AirStream 42WKN08-36 Hydronic Cassette Ceiling Fan Coil Units Instruction Manual

AirStream™
42WKN08-36
Hydronic Ceiling Cassettes
Installation, Operation and Maintenance Instructions

SAFETY CONSIDERATIONS

Installing and servicing air-conditioning equipment can be hazardous due to system pressure and electrical components. Only trained and qualified service personnel should install and service air-conditioning equipment. See Fig. 1 for Proposition 65 warning label. To assist in installation see Table 1 for conversion factors. Untrained personnel can perform basic maintenance such as cleaning and replacing filters. All other operations should be per- formed by trained service personnel. When working on air- conditioning equipment, observe safety precautions in literature and on tags and labels attached to the unit.

1. The equipment has been designed and manufactured to meet international safety standards but, like any mechani-cal/electrical equipment, care must be taken to obtain the best results.
2.  Service and maintenance of this equipment should only be carried out by skilled personnel.
3.  When working with any air-conditioning unit, ensure that the electrical disconnect supplying the unit is switched off prior to servicing or repair work and that there is no power to any part of the equipment.
4. Also ensure that there are no other power feeds to the unit such as fire alarm circuits, building management system (BMS) circuits, etc.
5.  Electrical installation, start-up and maintenance work on this equipment should be undertaken by competent and trained personnel in accordance with local relevant standards and codes of practice.

WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, injury or death, and could cause exposure to substances which have been determined by various state agencies to cause cancer, birth defects or other reproductive harm. Read the installation, operating and mainte- nance instructions thoroughly before installing or servicing this equipment.
IMPORTANT: The use of this manual is specifically intended for a qualified installation and service agency. A qualified installation and service agency must perform all installation and service of these appliances.
IMPORTANT:

• This appliance is not intended to be operated or serviced by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.
• Children should be supervised to ensure that they do not play with the appliance.

SPECIAL PRECAUTIONS

Special Precautions
The installation and maintenance instructions in this manual must be followed to provide safe, efficient, and trouble-free operation. In addition, particular care must be exercised regarding the special precautions listed below. Failure to properly address these  critical areas could result in property damage or loss, personal injury, or death. These instructions are subject to any more restrictive local or national codes.

Hazard Intensity Levels
DANGER: Indicates an imminently hazardous situation which, if not avoided, WILL result in death or serious injury.
WARNING: Indicates a potentially hazardous situation which, if not avoided, COULD result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided, MAY result in minor or moderate injury.
IMPORTANT: Indicates a situation which, if not avoided, MAY result in a potential safety concern.

DANGER
Appliances must not be installed where they may be exposed to potentially explosive or flammable atmosphere.

WARNING

• Disconnect power supply before making wiring connections or working on this equipment. Follow all applicable safety procedures to prevent accidental power up. Failure to do so can result in injury or death from electrical shock or moving parts and may cause equipment damage.
• All appliances must be wired strictly in accordance with the wiring diagram furnished with the appliance. Any wiring different from the wiring diagram could result in a hazard to persons and property.
• Any original factory wiring that requires replacement must be replaced with wiring material having a temperature rating of at least 221°F (105°C).
• Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not 5% greater than rated voltage.
• When servicing or repairing this equipment, use only factory-approved service replacement parts. Refer to the rating plate on the appliance for complete appliance model number, serial number, and company address. Any substitution of parts or controls not approved by the factory will be at the owner’s risk.

CAUTION

• Units not approved for use in potable water systems.
• Hot water supplied to the hot water heating option must not exceed 200ºF (93°C) temperature or 125 PSIG (862 kPa) pressure.
• Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not 5% less than the rated voltage.
• In order to avoid a hazard due to inadvertent resetting of the thermal cut-out, this appliance must not be supplied through an external switching device, such as a timer, or connected to a circuit that is regularly switched on and off by the utility.
• Do not attempt to reuse any mechanical or electrical component which has been wet. Such component must be replaced.
• When servicing the unit, some components may be hot enough to cause pain or injury. Allow time for cooling of hot components before servicing.

IMPORTANT:

• Unit Performance will be significantly reduced at or above 7215 ft (2200 m) and should not be operated above this altitude.
• For ceiling mounted units, check that the ceiling is capable of supporting the weight of the unit. If used within a ceiling grid, the ceiling grid is to be supported separately from the unit.
• No water-flow can cause a freeze condition resulting in damage to the coil.
• Never leave the unit filled with water in a building without heat unless antifreeze has been added.
• Start up and adjustment procedures, installation, and service of these appliances must be performed by a qualified installation and service agency.
• To check most of the Possible Remedies in the Troubleshooting guide, refer to the applicable sections of the manual.

CAUTION

Any original factory wiring that requires replacement must be replaced with wiring material having a temperature rating of at least 105°C. Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not more than 5% over rated voltage or  less than 5% under the rated voltage. When servicing or repairing of this equipment, use only factory-approved service replacement parts. Refer to the rating plate on the appliance for complete appliance model number, serial number and company address. Any
substitution of parts or controls not approved by the factory will be at the owner’s risk. Do not attempt to reuse any mechanical or electrical controllers which have been wet. Replace defective controller. Units not approved for use in potable water systems.
IMPORTANT: Make sure the ceiling grid is supported separately from the appliance. The ceiling must not be supported by any part of the appliance, fascia or any associated wiring or pipe work. Start-up and adjustment procedures should be performed by a qualified service agency.

www.P65Warnings.ca.gov

Table 1 — SI (Metric) Conversion Factors

INSPECTION

1. Inspect unit upon arrival. In case of damage, report immediately to transportation company and your local factory sales representative.
2. Check rating plate on unit to verify that the power supply meets available electric power at the point of installation.
3. Inspect unit received for conformance with description of product ordered (including specifications where applicable).

GENERAL

The 42WKN ceiling cassette units effectively make each area served an independently controlled temperature zone. Through thermostatic control of operations, conditions can be varied to suit diverse requirements or activities. Optional controls, plus outside and return-air connections, are available to provide for ventilation and recirculation of room air.
The 42WKN hydronic fan coil unit water connections are fixed to the unit body to avoid breaks when the pipes are connected. The upper coil connection is supplied with an air purge valve; the lower connection is supplied with a water purge valve. Minimum entering water temperature for the water circuit is 39°F (3.9°C); maximum is 180°F (82.2°C). If room temperature goes down to 32°F (0°C) or lower, it is advisable to empty the water circuit to avoid the potential for ice breaks. Refer to Tables 2 and 3 for unit physical data and Fig. 2-4 for unit dimensional data.

Table 2 — 42WKN Physical Data

Rating
Material: Fascia| Galvanized Steel
Material: Chassis| Finned Tube
CHILLED WATER COIL|
Type| Finned Tube
Quantity| 1
Face Area| ft²| 1.8| 2.8| 5.2
Nominal Airflow – Standard – H/M/L c| cfm| 330/300/260| 360/330/300| 600/540/460| 620/600/540| 940/850/740| 1080/940/850
Nominal Airflow – MERV 10 – H/M/Lc| cfm| 200/170/160| 520/490/450| 880/760/690
Discharge| 4-Way
Unit Water Volume| gal| 0.29| 0.45| 0.79
Maximum Inlet Water Pressure| psi| 125
FAN|
Type| Centrifugal
Quantity| 1| 2
Diameter| in.| 12| 15| 14
Horsepower (per fan)| hp| 1/8| 1/6
WEIGHTS|
Weight – Chassis| lb| 40| 64| 97
Weight – Fascia| lb| 5| 18| 21
CONNECTIONS|
Chilled Water Inlet| in.| 0.625| 0.875
Chilled Water Outlet| in.| 0.625| 0.875
Condensate (ID)| in.| 0.375
FILTRATION|
Type| Washable Polyester Foam (Standard)
Size| in.| 4.5 x 13.5 x 0.2| 11.6 x 23.2 x 0.2
Type| MERV 10
Size| in.| 13.0 x 13.0 x 1.0| 12.0 x 25.0 x 1.0
Quantity| 1| 2| 3
CONDENSATE PUMP|
Maximum Head| in.| 30
Nominal Flow-Rate| gpm| 0.1
OPTIONS|
Electric Heating Capacity| kW| 1.5| 3.0| 5.0
HW Heating Capacity d| BTU/hr| 17,100| N/A| 27,300| 27,900| 41,200| 45,200
HW Heating Capacity e| BTU/hr| 13,400| N/A| 24,800| 24,800| 42,300| 42,300
HW Coil Connection (OD)| in.| 0.625| N/A| 0.625
Max Supply Air Branch Duct| qty| 2
Supply Air Branch Duct Diameter| in.| 5| 6
Ducted Supply Air Volume f| cfm| 80| 100| 125| 200| 220
Fresh Air Connections| qty| 2| 3
Fresh Air Duct Diameter| in.| 3
Fresh Air Volume g| cfm| 40| 60| 65| 90| 95

NOTE(S):
a. Nominal cooling capacity based on 80/67°F (26.7/19.4°C) DB/WB, water temperature of 45ºF (7.2°C) inlet / 55ºF (12.8°C) outlet, 208V/1Ph/60Hz supply voltage, and Standard filters.
b. Nominal cooling capacity based on 80/67°F (26.7/19.4°C) DB/WB, water temperature of 45ºF (7.2°C) inlet / 55ºF (12.8°C) outlet, 208V/1Ph/60Hz supply voltage, and MERV10 filters.
c. Nominal airflow based on 208V/1Ph/60Hz supply voltage.
d. Nominal heating capacity based on 70/60°F (21.1/15.6°C) DB/WB, water temperature of 180ºF (82.2°C) inlet / 160ºF (71.1°C) outlet, 208V/1Ph/60Hz supply voltage, and Standard filters.
e. Nominal heating capacity based on 70/60°F (21.1/15.6°C) DB/WB, water temperature of 180ºF (82.2°C) inlet / 160ºF (71.1°C) outlet, 208V/1Ph/60Hz supply voltage, and MERV10 filters.
f. Maximum air volume available through one branch duct 6 ft (1.8m) long, with Cassette fan(s) at high speed and corresponding fascia aperture closed.
g. Maximum fresh air through all knockouts connected to one 10 ft (3.1 m) long duct with fan at high speed. Fresh air volume will depend on duct configuration, fan speed, and filter type.
LEGEND
ID — Inside Diameter
OD — Outside Diameter

Fire Rating
Material: Chassis| Galvanized Steel
CHILLED WATER COIL|
Type| Type Finned Tube
Quantity| 1
Face Area| m²| 0.17| 0.26| 0.48
Nominal Airflow – Standard – H/M/L c| m 3 /min| 9.3/8.5/7.4| 10.2/9.3/8.5| 17.0/15.3/13.0| 17.6/17.0/15.3| 26.6/24.1/21.0| 30.6/26.6/24.1
Nominal Airflow – MERV 10 – H/M/Lc| m 3 /min| 5.7 / 4.8 / 4.5| 14.7 / 13.9 / 12.7| 24.9 / 21.5 / 19.5
Discharge| 4-Way
Unit Water Volume| L| 1.1| 1.7| 3.0
Maximum Inlet Water Pressure| Pa| 861,845
FAN|
Type| Centrifugal
Quantity| 1| 2
Diameter| cm| 30.5| 38.1| 35.6
Horsepower (per fan)| W| 93.2| 124.3
WEIGHTS|
Weight – Chassis| kg| 18.1| 29.0| 44.0
Weight – Fascia| kg| 2.3| 8.2| 9.5
CONNECTIONS|
Chilled Water Inlet| cm| 1.6| 2.2
Chilled Water Outlet| cm| 1.6| 2.2
Condensate (ID)| cm| 0.95
FILTRATION|
Type| Washable Polyester Foam (Standard)
Size| cm| 36.8 x 34.2 x 0.5| 29.5 x 58.9 x 0.5
Type| MERV 10
Size| cm| 33.0 x 33.0 x 2.5| 30.5 x 63.5 x 2.5
Quantity| 1| 2| 3
CONDENSATE PUMP|
Maximum Head| cm| 76.2
Nominal Flow-Rate| l/m| 0.38
OPTIONS|
Electric Heating Capacity| kW| 1.5| 3.0| 5.0
HW Heating Capacity d| kW| 5.0| N/A| 8.0| 8.2| 12.1| 13.2
HW Heating Capacity e| kW| 3.9| N/A| 7.3| 7.3| 12.4| 12.4
HW Coil Connection (OD)| cm| 1.6| N/A| 1.6
Max Supply Air Branch Duct| qty| 2
Supply Air Branch Duct Diameter| cm| 12.7| 15.2
Ducted Supply Air Volume f| m 3 /min| 2.3| 2.8| 3.5| 5.7| 6.2
Fresh Air Connections| qty| 2| 3
Fresh Air Duct Diameter| cm| 7.6
Fresh Air Volume g| m 3 /min| 1.1| 1.7| 1.8| 2.5| 2.7

NOTE(S):
a. Nominal cooling capacity based on 80/67°F (26.7/19.4°C) DB/WB, water temperature of 45ºF (7.2°C) inlet / 55ºF (12.8°C) outlet, 208V/1Ph/60Hz supply voltage, and Standard filters.
b. Nominal cooling capacity based on 80/67°F (26.7/19.4°C) DB/WB, water temperature of 45ºF (7.2°C) inlet / 55ºF (12.8°C) outlet, 208V/1Ph/60Hz supply voltage, and MERV10 filters.
c. Nominal airflow based on 208V/1Ph/60Hz supply voltage.
d. Nominal heating capacity based on 70/60°F (21.1/15.6°C) DB/WB, water temperature of 180ºF (82.2°C) inlet / 160ºF (71.1°C) outlet, 208V/1Ph/60Hz supply voltage, and Standard filters.
e. Nominal heating capacity based on 70/60°F (21.1/15.6°C) DB/WB, water temperature of 180ºF (82.2°C) inlet / 160ºF (71.1°C) outlet, 208V/1Ph/60Hz supply voltage, and MERV10 filters.
f. Maximum air volume available through one branch duct 6 ft (1.8m) long, with Cassette fan(s) at high speed and corresponding fascia aperture closed.
g. Maximum fresh air through all knockouts connected to one 10 ft (3.1 m) long duct with fan at high speed. Fresh air volume will depend on duct configuration, fan speed, and filter type.
LEGEND
ID — Inside Diameter
OD — Outside Diameter

CONTROLS DESCRIPTION

Microprocessor Control Board
The PCB (printed circuit board) control board relays control the operation of the indoor-fan motor, outdoor-fan motor, compressor and electric heater (if fitted), to maintain room conditions at a user-defined set point. Temperature settings, fan speeds and other
control functions can be changed by the infrared (IR) transmitter or optional pendant. The controller PCB provides the following input/output facilities:

Inputs

•  T1 Return Air Temperature Sensor: 50K at 77°F (25°C)
• T3 Indoor Coil Temperature Sensor: 50K at 77°F (25°C)

Outputs
INDOOR FAN MOTOR
The controller will switch a combination of three 10 amp, 230-vac (3 speed settings) resistive rated relays to deliver the selected indoor fan speed.
CONDENSATE PUMP
The condensate pump will activate when unit is in cooling mode.
VANE MOTOR
A 10 amp, 230-vac resistive rated relay switches the vane motor on when Air Sweep is selected (unit sizes 18-36 only).
ELECTRIC HEAT
A 30 amp, 230-vac resistive rated relay switches the electric heater on when required.

External Connections

• Power input – Nominal 230-vac, 50/60 Hz
• Network connection – Twisted pair shielded cable

Refer to Fig. 5-34 for typical 42WKN unit wiring diagrams.

Microprocessor PCB Battery (P/N CR2032)
The microprocessor PCB is fitted with a battery backup system that maintains the CPU (central processing unit) memory and time clock settings during brief power outages. The battery is small, round and silver in appearance, similar to a wrist watch battery. When the unit is shipped, the battery is packed in a plastic bag and is placed inside the small rectangular box containing the infrared transmitter. The battery should be installed into the PCB’s battery holder approximately 5 minutes before main power is initially applied to the unit.
Controller
Before using the infrared transmitters, please read this handbook fully and ensure the batteries (supplied loose) are fitted into the IR transmitter.
A microprocessor mounted in a metal control box enclosure is used to control the entire unit operating functions with adjustments and settings being made from a hand-held IR transmitter or optional pendant.
The controls include the following basic components:

• PCB control board
•  Infrared transmitter or optional pendant
•  Infrared receiver (fascia)

See Fig. 35 on page 41 for controller button and icon information.

Infrared Receiver
The IR receiver (see Fig. 36 on page 41) is an extension of the control board and is located on the fascia of the unit, connected by a 7-pin plug and socket.
The green on/off indicator will be illuminated when the unit is running.
Yellow indicators show the present unit status, either “cool” or “heat.”
When both yellow indicators flash, the PCB control board battery needs to be changed.
NOTE: Be careful not to damage the holder when changing the battery.

Self Diagnostics
The microprocessor controller has a built-in diagnostics feature so that in the event of an alarm, the nature of the fault can be determined. The red timer/alarm LED (light-emitting diode) flashes on the fascia in a pre- determined frequency depending on the fault
as identified below:

1. Alarm LED flashes once every second: indoor coil sensor failure, low coil temperature or condensate high level trip.
2.  Alarm LED flashes once every 5 seconds: return air sensor failure.

Receiver Indicators
See Fig. 36 on page 41 and “Operation” on page 55 for an explanation of receiver indicators.

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2.  ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

WIRING LEGEND

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER
WIRING DIAGRAM
5H104889-1201
REV
R
Fig. 5 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 115v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1202

REV
R

Fig. 6 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 208v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1203

REV
R
Fig. 7 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 230v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1204

REV
R

Fig. 8 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 277v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1212

REV
R

Fig. 9 — 42WKN Unit 2-Pipe Cooling with Electric Heat, Microprocessor Control Wiring Diagram, 208v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1213

REV
R

Fig. 10 — 42WKN Unit 2-Pipe Cooling with Electric Heat, Microprocessor Control Wiring Diagram, 230v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1221

REV
R

Fig. 11 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 115v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1221

REV
R

Fig. 12 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 208v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1223

REV
R

Fig. 13 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 230v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104889-1224

REV
R
Fig. 14 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 277v, Sizes 08 and 12

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1201

REV
R
Fig. 15 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 115v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1202

REV
R
Fig. 16 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 208v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1203

REV
R
Fig. 17 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 230v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1204

REV
R
Fig. 18 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 277v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1212

REV
R
Fig. 19 — 42WKN Unit 2-Pipe Cooling Only with Electric Heat, Microprocessor Control Wiring Diagram, 208v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1213

REV
R
Fig. 20 — 42WKN Unit 2-Pipe Cooling Only with Electric Heat, Microprocessor Control Wiring Diagram, 230v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1221

REV
R
Fig. 21 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 115v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1222

REV
R

Fig. 22 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 208v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1223

REV
R
Fig. 23 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 230v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104890-1224

REV
R
Fig. 24 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 277v, Sizes 18 and 20

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1201

REV
R

Fig. 25 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 115v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1202

REV
R

Fig. 26 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 208v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1203

REV
R

Fig. 27 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 230v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1204

REV
R

Fig. 28 — 42WKN Unit 2-Pipe Cooling Only or 4-Pipe System with Microprocessor Control Wiring Diagram, 277v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1212

REV
R

Fig. 29 — 42WKN Unit 2-Pipe Cooling Only with Electric Heat, Microprocessor Control Wiring Diagram, 208v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1213

REV
R

Fig. 30 — 42WKN Unit 2-Pipe Cooling Only with Electric Heat, Microprocessor Control Wiring Diagram, 230v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1221

REV
R
Fig. 31 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 115v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1222

REV
R
Fig. 32 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 208v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1223

REV
R
Fig. 33 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 230v, Sizes 33 and 36

WARNING

1.  DISCONNECT POWER SUPPLY BEFORE MAKING CONNECTIONS TO PREVENT ELECTRICAL SHOCK AND EQUIPMENT DAMAGE.
2. ALL UNITS MUST BE WIRED STRICTLY IN ACCORDANCE WITH WIRING DIAGRAM  FURNISHED WITH THE UNIT. ANY WIRING DIFFERENT FROM THE WIRING DIAGRAM COULD RESULT IN A HAZARD TO PERSONS AND PROPERTY.
3. ANY ORIGINAL FACTORY WIRING THAT REQUIRES REPLACEMENT MUST BE REPLACED WITH WIRING MATERIAL HAVING A TEMPERATURE RATING OF AT LEAST 105°C.

IMPORTANT
INSTALLATION OF WIRING MUST CONFORM WITH LOCAL BUILDING CODES OR IN THE ABSENSE OF LOCAL CODES, OF THE NATIONAL ELECTRICAL CODE ANSI/NFPA 70
– LATEST EDITION. UNIT MUST BE ELECTRICALLY GROUNDED IN CONFORMANCE TO THIS CODE. IN CANADA, WIRING MUST COMPLY WITH CSA C22.1, PART 1, ELECTRICAL CODE.

FACTORY INSTALLED|
---|---
FIELD INSTALLED
TERMINAL BLOCK
COMPONENT TERMINAL
CONNECTED PATH
PLUG AND SOCKET
OPTIONAL COMPONENT

CHILLED WATER 2 POSITION
SMALL CASSETTE
MICROPROCESSOR CONTROLS
WITH OPTIONAL HOT WATER

WIRING DIAGRAM
5H104891-1224

REV
R
Fig. 34 — 42WKN Unit 2-Pipe Heating/Cooling Changeover with Microprocessor Control Wiring Diagram, 277v, Sizes 33 and 36

•      Power returned after break while Timer was active
Timer and On| Blinking synchronous| •      Fault F1 indication — error with unit mounted return air sensor
•      Fault on T4,0 input (input was opened for more than 10 seconds)
— Condensate high level
— Freeze stat alarm

Fig. 36 — Infrared Receiver

PRE-INSTALLATION

Unpack Unit
Remove the banding straps and lift the cardboard lid. Remove the fascia, packed in bubble wrap, and polystyrene packing pieces to expose the unit.
When removing the unit chassis from the box, the four corner brackets should be utilized for lifting. In order to protect the fascia from dirt and damage, it should be returned to the box until it is ready to be installed.
Blank Off Pieces
When branch ducting is to be used, polystyrene pieces for blanking off fascia openings are included with the fascia packing. Up to two opposing sides may be blanked off. See “Duct Collars” in Installation section, page 43.
Positioning

DANGER
Appliances must not be installed where they may be exposed to potentially explosive or flammable atmosphere.
IMPORTANT: Unit Performance will be significantly reduced at or above 7215 ft (2200 m) and should not be operated above this altitude.

The unit installation position should be selected with the following points in mind:

1. The appliance must be installed on a structure that is suitable to support the total weight of the appliance, piping, and condensate.
2. Piping, electrical panel and condensate pump access panel should be readily accessible for maintenance purposes. A 2 ft (0.61 m) clearance is recommended around the electrical panel and condensate pump access panel.
3. The unit should not be positioned less than 5 ft (1.5 m) from a wall or similar obstruction, or in a position where the discharge air could blow directly on to the thermostat. A 5 ft (1.5 m) clearance is required below the unit for service access.
4. The unit should not be positioned directly above any obstructions.
5. The unit must be installed square and level.
6. The condensate drain should have sufficient downward slope, 1 in. per 100 in. (2.5 cm per 254 cm), in any horizontal run between unit and drain. Maximum condensate pump lift is 30 inches (76.2 cm).
7. There should be sufficient room above the false ceiling for installing the unit. Minimum distance as shown in Fig. 37.
8. In case of high humidity, clogged or damaged condensate piping, incorrect installation or faulty condensate pump, water may drip from the unit. Do not install the appliance where dripping water can cause damage.

Ceiling Opening Sizes
An opening in the false ceiling will then have to be cut to the size shown in Table 4.

Fig. 37 — Minimum Distance to Ceiling
Table 4 — Ceiling Opening Dimensions

A cardboard template for ceiling cutout and rod positions is in- cluded with the unit.

Positioning the Electro-Mechanical Thermostat

In addition to positioning the unit correctly, it is very important to locate the wall-mounted thermostat in the optimum position to ensure good temperature control. Therefore, the installation should be selected with the following points in mind:

1.  Position the thermostat approximately 48 in. (122 cm) above floor level.
2. Do not position thermostat where it can be directly affected by the unit’s discharge airstream.
3.  Avoid external walls and drafts from windows and doors.
4.  Avoid positioning near shelves and curtains as these restrict air movement.
5.  Avoid heat sources e.g., direct sunlight, heaters, dimmer switches and other electrical devices.

INSTALLATION

IMPORTANT: Make sure the ceiling grid is supported separately from the appliance. The ceiling must not be supported by any part of the appliance, fascia or any associated wiring or pipe work.
IMPORTANT: For ceiling mounted units, check that the ceiling is capable of supporting the weight of the unit. If used within a ceiling grid, the ceiling grid is to be supported separately from the unit.

Step 1 — Hanger Bolts
The hanger bolts can now be installed at the centers shown in Fig. 38. Use 3/8 in. all thread rod.
Check the strength of the unit mounting hanger bolts. Refer to Tables 2 and 3 for unit weights.

Fig. 38 — Hanger Bolt Mounting Dimensions

Step 2 — Installation Guide
An installation guide is included in the Carrier Owner Information packet provided with the unit. Prepare the installation guide by folding the flat metal piece, by hand, along the perforations as shown in Fig. 39.

INSTALLATION GUIDE SETUP
Use an adequate number of personnel when moving the unit. A lifting device or at least two personnel should be used to lift the unit. The unit can be lifted onto the hanging rods and leveled at the correct distance from the ceiling with the aid of the installation
guide.

1. Hold the tab on the installation guide against the bottom of the cassette case with the guide pointing away from the cassette. See Fig. 40. Adjust the height of the cassette until the guide is level with the bottom of the false ceiling.
2. Secure the unit in position with locknuts and washers on both sides of the unit bracket. Ensure the threaded rod does not protrude more than 2 in. (5 cm) below the mounting bracket as shown in Fig. 41.

Step 3 — Condensate Piping

The unit is supplied with a 3/8 in. ID flexible hose for connection to copper or plastic drain piping.
When installing the unit, the following points should be remembered:

1.  Maximum pump lift is 30 inches (76.2 cm).
2. The highest point in the condensate piping should be as close to the unit as possible.
3. Condensate piping should slope downwards in the direction of water flow with a minimum gradient of 1 inch in 100 inches (2.54 cm per 254 cm). There must not be any uphill gradients other than in the first 30 in. (76.2 cm) of piping from the unit. Once the piping begins the downward gradient, the piping must continue to be in a downward gradient. See Fig. 42.
4. When multiple units are connected to a common condensate drain, ensure the drain is large enough to cope with the volume of condensate from all units. It is also recommended to have an air vent in the condensate piping to prevent any air locks.
5. Condensate piping must not be installed where it may be exposed to freezing temperatures.

Step 4 — Duct Collars
DUCT COLLARS
Supply air branch duct and outside air duct collars can be attached to the unit chassis by following the below steps:
SUPPLY AIR DUCT COLLARS

1. Up to two supply air ducts can be attached per unit.
2. Place the polystyrene blanking strip in the fascia supply air opening on the same side where the supply duct collar is to be installed.

OUTSIDE AIR DUCT COLLARS

1.  Two outside air openings are available on small casing sizes (size 08 and 12). Three outside air openings are available on medium and large casing sizes (size 18 and higher).
2. Replace the washable filter with the pleated filter provided with the fresh air duct collar kit.
3. To maximize the amount of outside air through the knockouts, use all available fresh air openings, the pleated filter, and high fan speed.

INSTALLING OUTSIDE AND/OR SUPPLY AIR DUCT COLLARS

1.  Refer to the dimensional drawings (Fig. 2-4 to for knock-out hole locations.
2. The insulation is pre-cut to aid location and removal of the relevant section. Rub hand across surface of insulation to reveal exact location of knock-out.
3. Remove the metal knockout from the chassis.
4.  Place the duct collar’s tabs inside the duct collar flange’s opening. Bend the tabs around the duct collar flange’s opening.
5. Using field provided self-tapping screws, attach the duct flange and collar to the chassis with the bent tabs being sealed in between the unit chassis and duct collar flange. See Fig. 43 for duct collar assembly.

NOTE: See Fig. 2-4 for branch duct and fresh air duct locations and dimensions.
Step 5 — Piping Installation

CAUTION

• Units not approved for use in potable water systems.
• Hot water supplied to the hot water heating option mustnot exceed 200ºF (93°C) temperature or 125 psig(862 kPa) pressure.

IMPORTANT:

• No water-flow can cause a freeze condition resulting in damage to the coil.
• Never leave the unit filled with water in a building without heat unless antifreeze has been added.

1. Branch piping to and from the unit should include swing joints to allow for expansion and contraction of the piping without placing a strain on the unit coil.
2. . Install pipe unions and shutoff valves in lines to and from each coil to allow maintenance or replacement of unit without shutting down and draining entire system. See Fig. 44.
3.  Include a circuit setter in return line for water flow regulation.
4. A drain valve (hose bib) should also be provided for each coil line to allow removal of water from the coil if located in an area subject to freezing.
5.  It is advisable to use a pipe line strainer before each coil.
6. Provide adequate pipe hangers, supports, or anchors to secure the piping system independently of the unit.
7. On 2-pipe systems with microprocessor controls, install the factory-provided Changeover Sensor on the main supply water line upstream from the unit where water maintains flow. This ensures accurate readings of water temperature. Wire extension and a plug are included.

PIPING INSULATION
Chilled water and condensate pipes should be insulated right up to the unit chassis to prevent condensation, which can damage the ceiling and objects located below the piping. Chilled water valves must also be insulated to prevent sweating.

Wiring

WARNING

• Disconnect power supply before making wiring connections or working on this equipment. Follow all applicable safety procedures to prevent accidental power up. Failure to do so can result in injury or death from electrical shock or moving parts and may cause equipment damage.
• All appliances must be wired strictly in accordance with the wiring diagram furnished with the appliance. Any wiring different from the wiring diagram could result in a hazard to persons and property.
• Any original factory wiring that requires replacement must be replaced with wiring material having a temperature rating of at least 221°F (105°C).
• Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not 5% greater than rated voltage.
• When servicing or repairing this equipment, use only factory-approved service replacement parts. Refer to the rating plate on the appliance for complete appliance model number, serial number, and company address. Any substitution of parts or controls not approved by the factory will be at the owner’s risk.

CAUTION

•  Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not 5% less than the rated voltage.
• In order to avoid a hazard due to inadvertent resetting of the thermal cut-out, this appliance must not be supplied through an external switching device, such as a timer, or connected to a circuit that is regularly switched on and off by the utility.

Installation of wiring must conform with local building codes, or in the absence of local codes, with the National Electric Code ANSI/NFPA (American National Standards Institute/National Fire Protection Association) 70 – Latest Edition. Unit must be electrically grounded in conformance to this code. In Canada, wiring must comply with CSA (Canadian Standards Association) C22.1, Electrical Code. Electric wiring must be sized to carry the full load amp draw of the motor, starter and any controls that are used with the unit. See Table 5 for electrical data. This equipment in its standard form is designed for an electrical supply of 208/230-1-60. When connection to a 115-1-60 supply is necessary, a factory-mounted step-up transformer must be fitted to the unit. Any damage to or failure of units caused by incorrect wiring of the units is not covered by warranty. Once the pipe work is complete, the electrical supply can be connected by routing the cable through the appropriate knockout and connecting the supply and ground cables to the unit’s power terminals. Low voltage control wiring can be run through alternate knockouts, provided in the side in the side of the control panel. NOTE: Low voltage control wiring can be run through alternate knockouts, provided in the side of the control panel.

Table 5 — Electric Data for All Voltages and for Units With or Without Electric Heat

42WKN NOMINAL CAPACITY

(DIGIT 6, 7)

| SUPPLY VOLTAGE (DIGIT 8)| PERFORMANCE (WITH ELECTRIC HEAT)| PERFORMANCE (NO ELECTRIC HEAT)
---|---|---|---
FLA| MCA| RECOMMENDED FUSE SIZE| FLA| MCA| RECOMMENDED FUSE SIZE

08 and 12 Small Chassis

| A: 115/60/1| —| —| —| 0.7| 0.9| 15
J: 110/50/1
B: 208/60/1| 6.2| 7.8| 15| ****

0.3

| ****

0.4

| ****

15

C: 230/60/1| 6.9| 8.6| 15
K:220/50/1| 6.6| 8.2| 15
H: 277/60/1| —| —| —| 0.3| 0.4| 15

18 and 20 Medium Chassis

| A: 115/60/1| —| —| —| 1.1| 1.4| 15
J: 110/50/1
B: 208/60/1| 12.3| 15.4| 20| ****

0.6

| ****

0.7

| ****

15

C: 230/60/1| 13.6| 17.0| 20
K: 220/50/1| 13.0| 16.3| 20
H: 277/60/1| —| —| —| 0.5| 0.6| 15

30 and 36 Large Chassis

| A: 115/60/1| —| —| —| 2.2| 2.8| 15
J: 110/50/1
B: 208/60/1| 20.8| 26.0| 30| ****

1.1

| ****

1.4

| ****

15

C: 230/60/1| 22.9| 28.6| 30
K: 220/50/1| 22.0| 27.4| 30
H: 277/60/1| —| —| —| 0.9| 1.1| 15

TERMINAL STRIP CONNECTIONS INSTALLATION

The terminal strip connections are designed to clamp down on the incoming building power and thermostat wiring connections. To properly connect the wires to the terminal strip:

1. Push a small flat head screwdriver into the square hole on the terminal. Press firmly until the screwdriver hits the back stop and opens the terminal. See Fig. 45.
2.  Remove approximately 3/8 in. (9.5 mm)of insulation from the end of the wire and push the stripped wire into the oval hole in the terminal.
3. Remove the screwdriver. Pull on the wire to make sure that it is securely clamped in the terminal.
4. Make sure that the terminal clamp is in contact with bare wire (insulation removed).

Disconnect Switch
For models with a factory installed disconnect switch (Digit 12 = D), the switch will be installed on the side of the control panel. See Fig. 46 and Fig. 2-4 dimensional drawings for the location of the control panel on the unit.

Refer to Fig. 47-52 for typical 42WKN unit wiring diagrams.

Fig. 47 — 42WKN Unit 2-Pipe (Cooling or Heating Only) or 4-Pipe with Electro-Mechanical Control Wiring Diagram, Sizes 08 and 12

Fig. 48 — 42WKN Unit 2-Pipe (Cooling or Heating Only) or 4-Pipe with Electro-Mechanical Control Wiring Diagram, Sizes 18 and 20

Fig. 49 — 42WKN Unit 2-Pipe (Cooling or Heating Only) or 4-Pipe with Electro-Mechanical Control Wiring Diagram, Sizes 33 and 36

Fig. 50 — 42WKN Unit 2-Pipe System with Heating/Cooling Changeover, Aquastat, and Electro-Mechanical Control Wiring Diagram, Sizes 08 and 12

Fig. 51 — 42WKN Unit 2-Pipe System with Heating/Cooling Changeover, Aquastat, and Electro-Mechanical Control Wiring Diagram, Sizes 18 and 20

Fig. 52 — 42WKN Unit 2-Pipe System with Heating/Cooling Changeover, Aquastat, and Electro-Mechanical Control Wiring Diagram, Sizes 33 and 36

Fascia Assembly

Once the piping and electrical services have been connected, the 4 fascia mounting bolts can be unscrewed approximately 1 in. (2.54 cm) from the condensate tray support channels. The fascia can now be unpacked for fitting to the unit chassis. Ensure the black fir tree fasteners holding the fascia polystyrene are pushed in firmly in case of transit vibration. If using branch ducting, the fascia aperture side opposite the ducting must be blanked off. Take one of the polystyrene blanking pieces and push it into the recess in the polystyrene fascia insulation. See Fig. 53. Install the fascia by removing the inlet grilles and filters, locating the 4 fascia mounting bolts on the chassis through the 4 keyhole brackets on the fascia and then sliding the fascia sideways until it locks into position. NOTE: Up to 2 non-adjacent sides can be blanked off.

NOTE: Make sure the foam insulating strip profile on the fascia matches the square and angled corners of the unit housing. Before tightening the fascia to the unit, connect the 2 halves of the vane motor’s plug and socket connection (unit sizes 18-36). On microprocessor-controlled units, ensure that the display panel cable is routed to the electrical panel and securely fastened to its connector on the microprocessor circuit board. (Refer to the unit’s electrical wiring schematic.) Take care to ensure that the connector is connected in the proper orientation and that the wires are not routed such that they may become trapped, cut, broken or chaffed. The fascia can now be tightened up to the unit chassis until a good seal is obtained between fascia and chassis.
NOTE: Do not over tighten the bolts. To do so may cause damage to the fascia. Reinstall filters in fascia. The inlet grilles can now be fitted to the fascia to complete the installation.

PRE-START-UP

IMPORTANT: Start up and adjustment procedures, installation, and service of these appliances must be performed by a qualified installation and service agency.
Pre-Start Checks
Once installation is complete, it is important that the following pre-start checks are made:

1. All piping is complete and insulated where necessary.
2. All fans are able to rotate freely.
3. All electrical connections (both power and control) are properly terminated.
4. All condensate drains are installed correctly.
5. The power supply is of the correct voltage and frequency.
6. The units are properly grounded in accordance with current electrical codes.
7.  For microprocessor-controlled units, check that the display panel cable is properly connected to the microprocessor main circuit board and that the jumper links are correctly set (refer to unit wiring schematic). If the links are set incorrectly, remove main power supply before making any changes.
8. For microprocessor-controlled units, check that the battery on the main circuit board is in place and properly connected. Check also that the batteries are installed in infrared/pendant transmitter. When a pendant transmitter is used, ensure it is properly located on to the wall mounting bracket.

Control Circuit Checks
A thorough pipe work check and pressure test should be performed before the unit controls are set up.

1. Isolate the unit from the chilled water supply. A system electrical check can now be carried out.

2. Switch on the indoor unit via the infrared/pendant transmitter or wall-mounted thermostat and check that the fan cycles correctly.
   NOTE: In some models there is a 2-minute fan run on time to remove residual heat from the unit if the unit is switched off during the heating mode.

3. On models with microprocessor controls, check that the high, medium and low fan speeds are operating correctly by changing the fan speed via the transmitter.

4. On unit sizes 18-36, check that the motorized vane sweep functions correctly by toggling the function on or off, either via the transmitter (microprocessor-controlled units) or via the toggle switch on the side of the electrical panel lid (electro-mechanical units).

5. On microprocessor-controlled units, if required, check that the built-in timer function is programmed and operating correctly. When the timer is activated, the yellow LED on the fascia display panel should be lit.

6. Check the operation of the condensate pump by pouring 7 to 8 ounces (198 to 277 grams) of water down the pump outlet, switch the unit on, select cooling mode and the lowest possible temperature set point, then observe the water being pumped from the unit. .

7. Check the operation of the chilled water valve by switching the system to the cooling mode and forcing a call for cooling.

8. Where fitted, check the operation of the hot water valve or the electrical heat elements by switching the system to the heating mode and forcing a call for heat.

9. Allow chilled water to enter the unit and vent air from the unit by opening the 1/4 in. (6.4 mm) air bleed. Re-tighten the bleed screw once all air has been removed. The units are now ready for the system balance to be performed.

NOTE: Any feedback may be submitted by fax to either the sale engineer or to the local Carrier office.
Fig. 54 — Start-Up Sheet Example

Sequence of Operation

ELECTRO-MECHANICAL CONTROLS

A 24-v signal from the thermostat to terminal G supplies power to the blower motor(s), condensate pump, and vane motor (if equipped). A toggle switch on the control box can be used to switch the oscillating vanes on or off. The condensate pump will run continuously during cooling operation, as long as there is a call for cooling. A call for heating, at terminal W, or cooling, at terminal Y, will energize the water valve actuator and allow water to flow through the cassette coil. When the call for heating or cooling is satisfied, the valve will close. If the temperature drops below the set point of the coil freezestat, the water valve with automatically open to circulate water through the coil. If the condensate float switch detects a high level of water in the condensate tray, the switch will open, activate the condensate pump and disable the heating/cooling signal until the water level drops down to normal.
MICROPROCESSOR CONTROLS
The microprocessor monitors indoor coil temperature and returnair temperature. The receiver contains a self-diagnostic feature. When a low indoor coil temperature is detected, the cooling action is stopped. If a sensor fails, then an alarm is displayed on the fascia mounted receiver.

OPERATION

When using the IR transmitter (see Fig. 35), always point the transmitter head directly at the receiver. At the time of transmission, the transmit indicator symbol will display and an audible alarm will be heard if the signal has been received. When the batteries are first installed, the transmitter or optional pendant default set point will be 64°F (17.8°C), low fan speed will be selected, and the system will be set to cool only mode.  When a parameter is changed in the Remote Control, it must be sent to the thermostat by pressing ON/SEND. Refer to Fig. 35 for button locations.

On/Off
Press the ON/SEND button to activate the air conditioner / fan coil unit and/or update information.

Fan Speeds
Press the FAN button to switch between fan speeds:

• High Speed|
---|---
• Medium Speed|
• Low Speed|
• Auto Speed|

Press the ON/SEND button to send information to thermostat.
Modes
Press the MODE button to switch between unit modes:

• Cool|
---|---
• Heat|
• Auto change-over|
•Fan only|

Press the ON/SEND button to send information to thermostat.

Temperature Setpoint

Adjust the desired temperature using the (+) or (–) buttons. Press the ON/SEND button to send information to thermostat.

Clock

1. Press the SELECT button. CLOCK SET will flash.
2. Press the (+) or (–) buttons. The hours will flash.
3. Adjust the hours using the (+) or (–) buttons.
4. Press the SELECT again. Minutes will flash.
5. Adjust the minutes using the (+) or (–) buttons.
6. Press the SELECT again to return to normal display mode.
7. Press the ON/SEND button to send information to the thermostat.

Timer
IMPORTANT: While setting the timer, if no button is pressed for 10 seconds, the display will return to normal display mode.

Start Time

1.  Press the SELECT button twice. PROGRAM and START (flashing) will appear on display.
2.  Press the SELECT button. The hours will flash.
3. Adjust the hours using the (+) or (–) buttons.
4. Press the SELECT button. The minutes will flash.
5. Adjust the minutes using the (+) or (–) buttons.

Stop Time

1. Press the SELECT button. PROGRAM and STOP (flashing) will appear on display.
2.  Press the SELECT button. The hours will flash.
3. Adjust the hours using the (+) or (–) buttons.
4.  Press the SELECT button. The minutes will flash.
5. Adjust the minutes using the (+) or (–) buttons.
6. Press the SELECT button. The TIMER will blink.
7.  Select TIMER ON (black timer icon) or OFF (white timer icon) using the (+) or (–) buttons.
8.  Press the ON/SEND button to send the information to the thermostat.

NOTE: When the Timer is active, and there is power failure to the thermostat, the display will show “ON” flashing.

Battery Replacement
When the batteries are low, the remote control display will dim. If the batteries are not replaced, the display will turn off completely.

1.  Pull the battery cover down to reveal the batteries.
2. Remove the old batteries.
3. Wait for 10 minutes before installing the new batteries.
4. Install 2 new AAA batteries. Pay attention to the polarity.
5. Replace the battery cover.

IMPORTANT: The remote control will not operate unless at least 10 minutes pass between removing the old batteries and installing the new ones.

CONTROLS

Setting Jumper Links

WARNING

•  Disconnect power supply before making wiring connections or working on this equipment. Follow all applicable safety procedures to prevent accidental power up. Failure to do so can result in injury or death from electrical shock or moving parts and may cause equipment damage.
• All appliances must be wired strictly in accordance with the wiring diagram furnished with the appliance. Any wiring different from the wiring diagram could result in a hazard to persons and property.
• Any original factory wiring that requires replacement must be replaced with wiring material having a temperature rating of at least 221°F (105°C).
• Ensure that the supply voltage to the appliance, as indicated on the serial plate, is not 5% greater than rated voltage.
• When servicing or repairing this equipment, use only factory-approved service replacement parts. Refer to the rating plate on the appliance for complete appliance model number, serial number, and company address. Any substitution of parts or controls not approved by the factory will be at the owner’s risk.

Table 6 — Jumper Link Control Features

mode, fan runs continuously. In heat mode, fan runs on demand.
**JMP2| 4-pipe configuration: Cool output connected to cooling device. Heat output connected to heating device.| 2-pipe configuration: Cooling and heating signals sent from cool output.
JMP3**| N/A| N/A

Jumper link settings must be made with the power turned off. Jumper link 1 will be factory set to SHORT, Jumper link 2 will be factory set to suit the type of unit, and Jumper link 3 will be factory set to OPEN.

Main Control Functions

INDOOR FAN OPERATION

The indoor fan will run continuously at the most recently set speed or will alter the speed according to the room temperature conditions when set to Auto mode. The indoor fan will continue to run until the unit is turned off by the user or via a pre-set time setting. When the unit is turned off during heating, the indoor fan will continue to run for approximately 2 minutes; this helps to dissipate residual heat from the electric heaters. In SLEEP mode the fan will cycle with a call for heating or cooling.
TEMPERATURE CONTROL
The controller will switch heating or cooling loads in order to maintain the temperature set point. The deadband is programmed to 4°F. Under normal operation, cooling or heating will be activated at the limits of the deadband and will continue to operate until set point is achieved. The temperature set point can be adjusted between 58ºF and 90ºF in 2ºF increments.
POWER FAILURE
The controller will auto restart in its previous mode of operation after a power failure, e.g., if the controller was turned on before power fail, after power is restored the controller will automatically turn on. Alternatively, if the controller was turned off before power fail after power is restored, the controller will remain off.

Alarms

The controller monitors the following alarm conditions:

• Return-air sensor failure
• Indoor coil under temperature (if freeze stat is on unit)
• Condensate high level

MAINTENANCE

CAUTION
When servicing or repairing this equipment, use only factory-approved service replacement parts. Refer to the rating plate on the appliance for complete appliance model number, serial number and company address. Any substitution of parts or controls not approved by the factory will be at the owner’s risk.

CAUTION

•  Do not attempt to reuse any mechanical or electrical controllers which have been wet. Replace defective controller.
• When servicing the unit, some components may be hot enough to cause pain or injury. Allow time for coolingof hot components before servicing.

Maintenance Schedule

EVERY 3 MONTHS
Check the air filter condition. Clean if necessary (see Filter Removal and Cleaning below).
EVERY 6 MONTHS

1.  Follow 3-month maintenance schedule in addition to below steps.
2.  Clean condensate tray with biocide suitable for polystyrene.
3.  Clean fascia.

EVERY 12 MONTHS

1.  Follow 6-month maintenance schedule in addition to below steps.
2.  Check all electrical connections for security.
3. Check condensate pump operation.
4. Check the heating and cooling action, to ensure proper operation.

Filter Removal and Cleaning

1. Disconnect power.
2.  Unclip the catches along the edge of each grille and allow them to hang from the fascia by the molded plastic hingeslocated along the opposite edge.
3. If desired, the grilles can be removed from the fascia com- pletely.
4.  Slide the filter out of the small plastic retaining clips on the back of each grille.
5. Gently vacuum clean the filters on a medium vacuum power.
6. When cleaned, reverse Steps 2-4 to replace the filters.

Recommended Spares
It is recommended that one complete set of air filters be kept on hand for use as needed.

DISASSEMBLY PROCEDURE

WARNING
Disconnect power supply before making wiring connections or working on this equipment. Follow all applicable safety procedures to prevent accidental power up. Failure to do so can result in injury or death from electrical shock or moving parts and may cause equipment damage.

Fan Removal

1. Unclip the grille catches and remove the grille(s) from the fascia.

2.  For unit sizes 08,12 only:
   a. Remove the fascia by loosening the 4 fascia mounting bolts and then slide the fascia horizontally until it releases from the chassis.
   b. Drain the condensate tray by removing the small black rubber drain plug, catching the condensate (if any) in a suitable container.
   c. Remove the self-tapping screws securing the two insulated metal condensate tray support channels and pull the channels away from the condensate tray.
   d. Pull the condensate tray downwards away from the chassis.
   For unit sizes 18-36 only:
   Remove the M6 screws from the black plastic inlet ring and pull the inlet ring downward from the condensate tray.

3.  Remove the electrical panel lid and disconnect the fan connections from within the electrical panel.

4.  Rotate the fan by hand until the 2 M6 nuts are visible through the fan mounting access holes. Remove the 2 nuts.

5. Rotate the fan 90 degrees until the remaining 2 nuts are visible and remove while supporting the fan to prevent it from falling. The fan can now be dropped down from the unit.

Condensate Tray Removal

1. Unclip the grille catches and remove the grille(s) from the fascia.
2.  Remove the fascia by loosening the fascia mounting bolts and then slide the fascia horizontally until it releases from the chassis. If the unit is microprocessor controlled, remove the display panel cable from within the electrical panel before removing the fascia.
3. Remove the self-tapping screws securing the 2 insulated metal condensate tray support channels and pull the channels away from the condensate tray. Pull the condensate tray, complete with inlet ring (inlet ring on unit sizes 18-36 only) downward away from the chassis. Be careful, as pan may still contain condensate.

Condensate Pump Removal

1.  Disconnect the condensate pump and float switch wires from inside the electrical panel.
2. Unscrew the 3 M4 screws holding the pump inspection plate in place and pull the pump and mounting bracket away from the chassis while feeding the pump wires between condensate tray and insulation.

TROUBLESHOOTING

See Table 7 for troubleshooting information.

WARNING

• Disconnect power supply before making wiring connections or working on this equipment. Follow all applicable safety procedures to prevent accidental power up. Failure to do so can result in injury or death from electrical shock or moving parts and may cause equipment damage.
• When servicing or repairing this equipment, use only factory-approved service replacement parts. A complete replacement parts list may be obtained by contacting the factory. Refer to the rating plate on the appliance for complete appliance model number,  serial number, and company address. Any substitution of parts or controls not approved by the factory will be at the owner’s risk.

CAUTION
Do not attempt to reuse any mechanical or electrical component which has been wet. Such component must be replaced.
When servicing the unit, some components may be hot enough to cause pain or injury. Allow time for cooling of hot components before servicing.

IMPORTANT:

•  Start up and adjustment procedures, installation, and service of these appliances must be performed by a qualified installation and service agency.
•  No water-flow can cause a freeze condition resulting in damage to the coil.
• Never leave the unit filled with water in a building without heat unless antifreeze has been added.
•  To check most of the Possible Remedies in the Troubleshooting guide, refer to the applicable sections of the manual.

Table 7 — Troubleshooting

Two LEDs Flashing (Microprocessor Units Only)

| Faulty float switch

(Connected to microprocessor terminals ‘T4’)

| See Condensate High Level section in this table.
Fan thermal trip (Connected to microprocessor terminals ‘T4’)| See Fans Will Not Run section in this table.
Freeze stat alarm (Connected to microprocessor terminals ‘T4’)| —
Return air sensor failure (Connected to microprocessor terminals ‘T1’)| After checking the above, use the unit wiring schematic to isolate the return air sensor and measure the resistance. Sensor is 50K at 72°F type. Check and replace if necessary.

Unit Will Not Operate

|

No power mains power

| Check power supply to the unit. For microprocessor units, check power to the microprocessor and check the on-board microprocessor fuse.
No 24-v control circuit power| Check the 24-v feed from the control transformer. If not present, check transformer windings and replace if necessary.

Control circuit disabled by unit protection device

| In some models, particularly electro-mechanical units, some protection devices (such as freezestats, fan trips, etc.) are wired in line with the 24-v control circuit feed to cause the unit to shut down in an alarm condition . Use the unit’s wiring schematic to identify these devices and investigate accordingly.

Infrared receiver failure (microprocessor units only)

| If the green LED is lit or flashing, receiver is OK. If there are no lit LEDs and the unit will not respond to the transmitter, press the on/off button on the fascia display panel. If the unit responds to the on/off button receiver is OK. Check transmitter.
Transmitter failure (microprocessor units only)| Try new batteries first. If no response, press on/off button on unit fascia. If the unit responds to the on/off button transmitter is faulty.
Microprocessor failure (microprocessor units only)| The microprocessor is the least likely component to be at fault. Investigate all other possibilities in every section of this troubleshooting guide first. Replace the microprocessor only after all other avenues of investigation are exhausted.

Fans Will Not Run

| Loose wire| Check all fan wire connections. Use unit’s electrical schematic to verify that fan is wired correctly.
Faulty fan capacitor| Check fan capacitors and replace if necessary.
Faulty fan motor| Check fan motor protector for open circuit, and replace if necessary.
Fan thermal trip| Motor temperature limits exceeded. Check fan motor protector for open circuit, and replace if necessary.

Faulty PCB

| On electro-mechanical units check for a signal at “G” terminal.
On microprocessor units check for steady green light on display panel.

No Cooling

| Incorrect MODE setting (microprocessor units only)| Check that the transmitter MODE is set to Cooling or Auto Mode.
Set point too high| Check the set point on the transmitter or wall-mounted thermostat and adjust if necessary.
Dirty or blocked air filter| Check filter condition.
High condensate level trip| Drain the condensate tray and investigate. See Condensate High Level section.
Sensor failure (microprocessor units only)| If any of the sensors are faulty, the microprocessor will disable the cooling operation. (See the “Self Diagnostics” section on page 10.)
Faulty valve actuator (chilled water units only)| Check cooling signal present at actuator. Check actuator by manually opening the valve. Replace actuator if necessary.

Condensate High Level (Microprocessor Units: LEDs Will Flash)

| Maximum pump lift exceeded| Check that the condensate pump head is no greater than 30 in. (See page 42 of this manual for installation guide.)
Blocked/kinked condensate pipe| See Water Leaking from Unit section in this table.
Condensate pump blocked or failed| See Water Leaking from Unit section in this table.
Coil freeze up| A coil freeze condition may have caused excessive condensate to collect in the drip tray.

LEGEND
LED — Light-Emitting Diode
PCB — Printed Circuit Board

Table 7 — Troubleshooting (cont)

Water Leaking from Unit (also see Condensate High Level Section)

| Condensate plug loose or missing| Check that the rubber condensate plug is securely fitted to the underside of the unit’s polystyrene drip tray. On some models this is located underneath the fascia support rails on the pump side of the unit.

Unit installed unevenly

| With fascia removed, ensure that the unit chassis is level (at the face) both front to back and left to right, to ensure correct condensate flow.
Condensate drain piping installed incorrectly| Check that the site installed condensate gravity drain slopes ‘downhill’ away from the unit. (See page 42 of this manual for installation guide.)
Blocked/kinked condensate pipe| Check condensate piping for blocks/kinks, clear as necessary. Check for a water tight connection between the condensate outlet and the site installed condensate gravity drain.
Condensate pump blocked or failed| Clear any blockages and ensure that power is being applied to the pump. If the pump still does not run, replace the pump.

Float switch failure

| Check that the float switch operates correctly and is properly positioned. Float switch is normally closed, opens on rise of water level.

No Heating (Hot Water)

| Incorrect MODE setting (Microprocessor units only)| Check that the transmitter MODE is set to Heat or Auto Mode.
Set point too low| Check the set point on the transmitter or wall mounted thermostat and adjust if necessary.
Blocked or dirty filters causing low airflow| Check condition of filters. (See page 57 for filter removal and cleaning instructions.)
No hot water/pumps failed| Check hot water source and supply to unit.
Faulty valve/actuator| Check actuator by manually opening and closing valve, replace if faulty.
Faulty heater relay| Check signals to relay and check action of relay contacts. Replace relay or PCB if necessary.

No Heating (Electric Heat)

| Incorrect MODE setting (microprocessor units only)| Check that the transmitter MODE is set to Heat or Auto Mode.
Set point too low| Check the set point on the transmitter or wall-mounted thermostat and adjust if necessary.

Overheat cutout tripped (Also see Electric Overheat section)

| Investigate cause of over heat condition. Possible low airflow, check filter condition.
(See page 57 for filter removal and cleaning instructions.) Possible fan failure. Check fans.
(See Fans Will Not Run section.)
Remove power from unit and reset manual overheat cutout by rubbing. DO NOT PRESS. Consult Factory for instruction if necessary.
Heater element failed| Investigate and replace if necessary.
Faulty heater relay| Check signals to relay and check action of relay contacts. Replace relay or PCB if necessary.
Electric Overheat| Automatic or manual reset overheat cutout tripped| The electric heat circuit contains one automatic reset and one manual reset overheat cutout protection switch for each electric heat element fitted to the unit. The cutouts are wired in line with the main power flowing in each element and operate as described below.
Automatic cutout: If the auto cutout trips, the electric heat is temporarily disabled until the unit temperature falls and causes the overheat cutout to automatically reset.
Manual cutout: If the manual cutout trips, the electric heat is disabled until the unit temperature falls and the overheat cutout is manually reset. It will typically take five minutes for the unit temperature to fall sufficiently to allow the cutout to be reset. The cutout should only be reset by a qualified and competent electrician and with the main power switched off. Ensure the elements have cooled sufficiently.

LEGEND
LED — Light-Emitting Diode
PCB — Printed Circuit Board

REPLACEMENT PARTS
Please quote the unit type and unit serial number when ordering replacement parts or contacting the factory about the unit. This information can be found on the serial plate attached to the unit. See Fig. 55.
When a component part fails, contact your local Carrier representative to order a replacement part. See Fig. 56 for the 42WKN unit exploded views and parts lists. If the part is considered to be under warranty, the following details are required to process this requirement:

1. Full description of part required, including the unit’s part number, if known.
2.  The original equipment serial number.
3. An appropriate purchase order number.

DESCRIPTION

1| Cassette Chassis
2| Chilled  Water Coil
3| Electric Heater Element Assembly
4| Condensate Tray
5| Condensate Tray Supports (2)
6| Condensate Pump
7| High Level Switch
8| Condensate Pump Assembly (Shown Inverted)
9| Fan/Motor Assembly
10| Coil/Return Air Sensors (Microprocessor Only)
11| Grille
12| Label
13| Air Deflector Vanes (4)
14| Freeze Protection Thermostat
(Electro-Mechanical version only)
15| Filter
16| Fascia Assembly
17| Receiver (Microprocessor Only)
18| Terminal Rail, Relays and Timer
(Micro and Electro-Mechanical Version)
19| Control Box Lid
20| Control Box
21| PCB Controller (Microprocessor Only)
22| Coil Support Brackets
23| Remote Handset (Microprocessor Only)

Fig. 56 — 42WKN08, 12 Unit Exploded View and Parts List

© 2023 Carrier
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53420027-01
Printed in U.S.A.
Form 42WKN-11SI
11-23
Replaces: 42WKN-10SI

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