LENNOX MCB and MWCB Single Zone Mini Split System Instruction Manual

MCB and MWCB Single Zone Mini Split System
Instruction Manual

MCB and MWCB Single Zone Mini Split System

WARNING
Improper installation, adjustment, alteration, ser vice or maintenance can cause property damage, personal injury or loss of life.
Installation and service must be performed by a li censed professional HVAC installer (or equivalent) or a service agency.

General
Refer to the Product Specifications bulletin (EHB) for more product information.
These instructions are intended as a general guide and do not supersede local or national codes in any way. Authorities having jurisdiction should be consulted before installation.
The MFMA Floor Mount Console unit is matched with an outdoor heat pump unit to create a mini-split system that uses HFC-410A refrigerant.

Use of Mini-Split System During Construction
Lennox does not recommend the use of its mini-split systems during any phase of construction. Very low return air temperatures, harmful vapors and operation of the unit with clogged or misplaced filters will damage the system.
However, mini-split systems may be used for cooling of buildings under construction, if the following conditions are met:

• Air filter must be installed in the system and must be maintained during construction.
• Air filter must be replaced upon construction comple-tion.
• The indoor wall unit assembly must be thoroughly cleaned following final construction clean-up.
• All mini-split operating conditions must be verified ac-cording to these installation instructions.

Included Parts
Package 1 of 1 contains the following: 1 – Assembled Indoor Unit

Optional   Accessories

Indoor / Outdoor Unit Match-Ups

WARNING
The clean Air Act of 1990 bans the intentional venting of refrigerant (CFCs, HCFCs, and HFCs) as of July, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.

CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.

Model Number Identification

CEILING/FLOOR NON-DUCTED INDOOR UNITS

Typical Single-Zone System Components

System Dimensions
Outdoor Units

Indoor Units

Torque Requirements for Caps and Fasteners

When servicing or repairing HVAC components, ensure the fasteners are appropriately tightened. “Table 1. Torque Requirements” provides torque values for fasteners.

IMPORTANT

Only use Allen wrenches of sufficient hardness (50Rc – Rockwell scale minimum). Fully insert the wrench into the valve stem recess.
Service valve stems are factory-torqued from 9 ft.-lbs. (12 N) for small valves, to 25 ft.-lbs. (34 N) for large valves) to prevent refrigerant loss during shipping and handling. Using an Allen wrench rated at less than 50Rc risks rounding or breaking off the wrench, or stripping the valve stem recess.
See the Lennox Service and Application Notes C-08-1 for further details and information.

Torque Requirements

CAUTION

In order to avoid injury, take proper precaution when lifting heavy objects.

Unit Placement Considerations

AVOID
Do not install the unit in the following locations:

• Areas exposed to petrochemicals or petrochemical products.

• Areas exposed to salt or other corrosive materials or caustic gases.

• Areas exposed to extreme voltage variations (such as factories.
  Tightly enclosed areas that may impede service of the unit.
  Areas exposed to fossil fuels (such as oil or gas in kitchens).

• Areas exposed to strong electromagnetic forces.

• reas exposed to acids or alkaline detergents.

•  Place the unit so that it is not exposed to direct sun-light.

•  Ensure the structural ceiling can support the weight of the unit.

• Select a location where condensate line will have the shortest run to a suitable drain per local codes.

• Allow sufficient space around unit for proper operation and maintenance.
  Install unit a minimum of 3 feet (1m) away from any antenna, power cord (line) radio, telephone, security system, or intercom. Electrical interference and radio frequencies from any of these sources may affect op-eration.

• Be sure to instruct customers how to properly operate the unit (especially maintenance of air filter, and operation procedure) by having them carry out operations themselves while looking at the manual provided with the controller Floor Installation

• Locate a suitable position within the space where maintenance access and supply air will not be restrict-ed or affected by obstacles. See “Figure 6. Indoor Unit Clearances – Inches (mm)” on page 7 for minimum clearances.

• Place the MFMA on a wall which is both capable of supporting the unit’s weight and which is constructed to enable the unit to fit flush on the wall. An uneven wall may lead to vibration and subsequent unit dam-age.

Units are wall mounted using two factory-provided hanging brackets.

IMPORTANT

Make sure that drain piping is properly routed and insulated to prevent both leaks and condensation.

1. Use a field-provided hose clamp to secure the drainline stub on the side of the cassette base to a field-supplied 1” (25 mm) drain line.
   NOTE:  Take care not to over-tighten the hose clamp as
   this may damage the drain line stub.
   NOTE:  Connection between stub and drain line must be watertight. Apply non hardening plumbing joint compound if needed to ensure a watertight seal.

2. Confirm proper slope (not less than 1/4 inch per foot (18 mm per m)) and routing of condensate lines to ensure moisture is drained away from the indoor unit.

3. Drain should be as short as possible and should not have any droops or kinks that would restrict condensate flow and shall be approved resistant pipe. There must be a 2-inch (51 mm) space between the end of the condensate drain and the final termination point (ground, open drain, etc.) to ensure that the line will drain freely.

4. After the system installation is complete, the condensate drain line must be checked for leaks and proper drainage. If a field-provided condensate pump has been installed, it must be checked to ensure proper operation. This check is part of the start-up process which must be done by the installing contractor.

IMPORTANT
Drain should have a slope of at least ¼ inch per foot and should be approved corrosion-resistant pipe. You must confirm operation of every drain and pump in the system as part of the commissioning procedure.

Outdoor Unit Installation
Placement Considerations

CAUTION

In order to avoid injury, take proper precaution when lifting heavy objects.

Consider the following when positioning the unit:

• In coastal areas or other places with salty atmosphere of sulfate gas, corrosion may shorten the life of the unit. In coastal areas, the coil should be cleaned with potable water several times per year to avoid corrosive buildup (salt).

• Some localities are adopting sound ordinances based on the unit’s sound level registered from the adjacent property, not from the property where the unit is in-stalled. Install the unit as far as possible from the prop-erty line.

• When possible, do not install the unit directly outside a window. Glass has a very high level of sound trans-mission.

• Install unit level.

• Choose a place solid enough to bear the weight and vibration of the unit, where the operation noise will not be amplified.

• Choose a location where the hot air discharged from the unit or the operation noise will not be a nuisance to neighbors.

• Avoid installing the outdoor unit near a bedroom or other places where noise may cause a problem

• There must be sufficient space to carry the unit into and out of the site.

• There must be unobstructed air flow around the air in-let and the air outlet.

•  The unit must not be installed in areas where a flam-mable gas leak may occur.

• Install the outdoor unit a minimum of 3 feet (1m) away from any antenna, power cord (line), radio, telephone, security system, or intercom. Electrical interference and radio frequencies from any of these sources may affect operation.

• Since water drains from the outdoor unit during vari-ous stages of operation, do not place anything which may be damaged by moisture under the unit.

Direct Sunlight, Rain, Snow and Ice Protection

• If the outdoor unit is subjected to prolong exposure to direct sunlight with temperatures over 100°F (38°C) a canopy is suggested as illustrated in “Figure 9. Out-door Unit on Pedestal (Stand) and Protective Canopy” or “Figure 14. Dog House-Style Shelter” on page 10.

IMPORTANT
The construction of a canopy or shade is necessary because of an ambient limit control set to 122°F (50°C) to protect the electronics. If the outdoor unit is placed in direct sunlight it is possible that the limit may activate and shut down the unit.

• Place unit away from overhanging roof lines which would allow water or ice to drop on, or in front of, coil or into unit. Construct a canopy as illustrated in “Fig-ure 9. Outdoor Unit on Pedestal (Stand) and Protec-tive Canopy”.
• The unit base should be elevated above the depth of average snows as illustrated in “Figure 10. Outdoor Unit on Brackets above Snow Line”.
• In heavy snow areas, do not place the unit where drift-ing will occur as illustrated in “Figure 11. Outdoor Unit Air Flow Obstructed by Snow” on page 10.
• Carefully consider how to manage defrost water dis-posal to prevent ice from blocking walkways or creat-ing a safety hazard near the outdoor unit as illustrat-ed in “Figure 12. Avoid Defrost Water Ice Hazard” on page 10.

Prevailing Winds

Normally wind baffles are not required for a outdoor unit. However, in order to maximize reliability and performance, the following best practices should be followed.
If unit coil cannot be installed away from prevailing winter winds, some method of protecting the coil is recommended. However, minimum clearances as reference in “Figure 5. Outdoor Unit Clearances – Inches (mm)” on page 6 must be observed at all times.
Common application examples are:

• When prevailing winds are from the air inlet side, then position the wind barrier a minimum of 12 inches (305 mm) from the unit as illustrated in “Figure 13. Wind Barrier”.
• When prevailing wind is into the discharge side, then position the wind barrier a minimum 79 inches (2007 mm) from the front of the unit as illustrated in “Figure 13. Wind Barrier”.
• Outdoor unit can be installed in a dog house style shelter as illustrated in “Figure 14. Dog House-Style Shelter”.
• a roof overhang as illustrated in “Figure 15. Unit in-stalled in Alcove”.

Buried Refrigerant Pipe Protection

• All refrigerant lines must be insulated regardless of if it is buried.
• In addition to insulating each line of piping, buried lines must rest inside a sealed, watertight conduit.
• The conduit must be designed so it cannot collect and retain water.

Outdoor Unit Condensate Piping

Condensate formed during the heating and defrost processes must be drained from heat pump units. Drain holes are provided in the base of the units to ensure proper drainage.

• Heat pumps must be raised when installed on a con-crete pad or the ground to allow drainage to occur.
• If the heat pump unit is installed on wall mounting brack-et, insert the provided drain connector into one of the 1 inch (25 mm) drain holes and attached a field-provided insulated drain hose to the connector. Use field-provid-ed rubber plugs to cover any unused drain holes if the unit is installed over a walk way or door.

Slab or Roof Mounting
Install the unit a minimum of 4 inches (102 mm) above the roof or ground surface to avoid ice build-up around the unit. Place the unit above a load bearing wall or area of the roof that can adequately support the unit. Consult local codes for rooftop applications.

CAUTION

This system contains both refrigerant and oil. Some rubber roofing material may absorb oil. This will cause the rubber to swell when it comes into contact with oil. The rubber will then bubble and could cause leaks. Protect the roof surface to avoid exposure to refrigerant and oil during service and installation. Failure to follow this notice could result in damage to roof surface.

Securing Outdoor Unit to Slab, Frame, or Rails
If the outdoor unit is installed on a field-provided slab or frame, use lag bolts or equivalent to secure the outdoor unit to the slab or frame.

Securing Outdoor Unit To Hanging Brackets
If the outdoor unit is installed on field-provided wall mounting brackets, use lag bolts or equivalent to secure the outdoor unit to the bracket. Minimum rear clearance can be reduced to 6 inches (152 mm) when mounted on brackets and with no obstructions on the other three sides. Allow for condensate disposal when placing units above one another.

Refrigerant Piping Connections

Line sets consists of two copper pipes connecting the outdoor unit to the indoor unit. “Table 3. Refrigerant Piping and Indoor Unit Connection Sizes” lists the connection sizes. The connections are made using the provided brass flare nuts at the end of the refrigerant piping connections.

1. Choose the correct pipe sizes for your application using “Table 3. Refrigerant Piping and Indoor Unit Connection Sizes” on page 12.

2. Confirm that you are using the correct diameter piping.

3. Determine the necessary piping length required for the application.

4. Cut the selected pipes with a pipe cutter. Make the cuts flat and smooth as illustrated in “Figure 20.

5.  Insulate the copper piping.

6. Insert a flare nut onto each pipe before flaring.

7. Use “Table 2. Flaring Piping” on page 12 to properly

8. After flaring the pipe, temporarily sealed pipe ends with adhesive tape to avoid contaminants from entering the pipes.

9. The seal on the unit refrigerant piping connections should remain in place until the last possible moment.

10.  This will prevent dust or water from getting into the refrigerant piping before it is connected.

11. CAREFULLY  adjust refrigerant piping connections to suit the application.

12. Slowly loosen one of the flare nuts to release the factory nitrogen charge from the indoor units only.

13. Remove the flare nuts from the connections on the unit and discard the seal from each of the piping connections.

14. Slide the flare nuts onto the ends of the field-provided refrigerant piping before using a suitable flaring tool to flare the end of the copper pipe.

15. Apply recommended HFC-410A refrigerant lubricant to the outside of the flared refrigerant lines.
    IMPORTANT
    The compressor in this unit contains PVE oil (Polyvinylether). PVE oil is formulated for hydrofluorocarbon (HFC) refrigerants, such as HFC-410A, which this system contains. While it may have some miscibility properties with mineral-based oil and POE oil (Polyolester), it is not recommended to mix PVE oil with any other type of refrigerant oil.

16. 16. Align the threaded connections with the flared refrigerant lines. Tighten the flare nuts lightly at first to obtain a smooth match as illustrated in “Figure 21. Making Connections (Male to Female Connection)”.

17. Once snug, continue another half-turn on each nut which should create a leak-free joint. A torque wrench may be used to tighten flare nuts using “Table 4. Flare Nut Torque Recommendations” on page 13. Do not over-tighten a flared joint. Flared connections should always be accessible and must be insulated to prevent condensation.

18.  After refrigerant piping has been installed and checked for leaks, apply insulation over all flared connections.

**Outside Diameter| Recommended Torque| No torque wrench available Finger tighten and use an appropriately sized wrench to turn an additional:
---|---|---
Inches**
1/4| 15 ft.-lb. (20 N)| 1/4 turn
1/2| 41 ft.-lb. (56 N)| 7/8 turn

Leak Test and Evacuation

Air and moisture remaining in the refrigerant system will have undesirable effects as indicated below:

• Pressure in the system rises.
• Operating current rises.
• Cooling or heating efficiency drops.
• Moisture in the refrigerant circuit may freeze.
•  Water may lead to corrosion of parts in the refrigera-tion system.

The line set between the indoor and outdoor units must be leak tested and evacuated to remove any non-condensables and moisture from the system.

Leak Test
Use the following procedure to test for system leaks:

1. Connect the manifold gauge set and dry nitrogen gas cylinder to the liquid and gas service ports.
2. Open valve on nitrogen cylinder.
3. Pressurize the system per the pressure test specifications in “Table 6. Pressure Test Specifications”.
4. Check that the system pressure remains stable. If there is any movement check system for leaks.
5. After the system is found to be free of leaks:

• Close valve on nitrogen cylinder
• Relieve the nitrogen pressure by: loosening the charge hose connector at the nitrogen cylinder
• When the system pressure is reduced to normal, disconnect the hose from the cylinder

| Bar| Psig| kPa| Duration
---|---|---|---|---
1| 3| 44| 303| Minimum of 10 minutes
2| 15| 220| 1517| Minimum of 10 minutes
3| 32| 470| 3241| Minimum of 10 minutes
4| 45| 650| 4482| 1 hour. Stress test to prove the integrity of the complete installation.
5| 32| 470| 3241| 24 hours. Lower system pressure test, after confirmation No. 4 was successfully completed.

IMPORTANT

Use only oxygen-free nitrogen (OFN).
Triple Evacuation Procedure
A Micron or Torr gauge must be used for this procedure.

1. Discharge the oxygen-free nitrogen and evacuate the system to a reading of 8000 Microns (8 Torr) using all service valves.
2. Break the vacuum by allowing nitrogen into the port connections (liquid and gas line pipes) until a positive pressure is achieved.
3. Evacuate the system to a reading of 5000 Microns (5 Torr).
4. Break the vacuum by allowing nitrogen into the port connections (liquid and gas line pipes) until a positive pressure is achieved
5. Evacuate the system to a minimum reading of 500 Microns (0.5 Torr).
6. For a moisture-free system, ensure the vacuum is held without movement for a minimum of 4 hours.
7. If vacuum fails to hold, carry out steps 2 through 6 until vacuum holds.

Wiring Connections

WARNING
Electric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national and local codes.
Line voltage is present at all components when unit is not in operation. Disconnect all remote electric power supplies before opening access panel. Unit may have multiple power sources.

CAUTION
All terminal connections must be made as illustrated in the following diagrams. Improperly connected wiring could damage unit or cause communication errors between indoor and outdoor units.
In the U.S.A., wiring must conform with current local codes and the current National Electric Code (NEC). In Canada, wiring must conform with current local codes and the current Canadian Electrical Code (CEC).

Outdoor Unit

• Refer to unit nameplate for minimum circuit ampacity and maximum over-current protection size.
• Make all electrical power wiring connections at the out-door unit.
• Be sure to reattach all electrical box covers after con-nections are complete.

Indoor Unit

• All indoor units are powered by the outdoor unit.
• Communication Wiring (Indoor Units 30K and Below): Use one stranded 4-conductor wire to provide power and communication.
• Communication Wiring (Indoor Units 36K and Above): Use one stranded 3-conductor wire to provide power and one stranded 2-conductor wire to provide communication.
• Use minimum of 15 GA stranded wiring.
• When installing a condensate pump, wire in-line with the CN5 float switch.

IMPORTANT
This unit must be properly grounded and protected by a circuit breaker. The ground wire for the unit must not be connected to a gas or water pipe, a lightning conductor or a telephone ground wire.
Do not connect power wires to the outdoor unit until all other wiring and piping connections have been completed.
Do not install the unit near a lighting appliance that includes a ballast. The ballast may affect remote control operation.

IMPORTANT
All diagrams are typical. Refer to the wiring diagram on the unit for actual wiring.

IMPORTANT
Install unit so that unit disconnect is accessible.
Use specified wiring and cable to make electrical connections. Clamp cables securely and make sure that connections are tight to avoid strain on wiring. Insecure wiring connections may result in equipment failure and risk of fire.
Wiring must be installed so that all cover plates can be securely closed.

System and Terminal Designations| System Capacity| System Voltage| Number of Conductors| Wire Type| Wire Gauge/MCA
---|---|---|---|---|---
Indoor to Outdoor Wiring (Communication/  Power)1, 2, 3 and GND| 12K| **** 208/230VAC| 4| Stranded and unshielded| 16AWG
Outdoor to Main Power L1, L2 and GND| 12K| 208/230VAC| 3| Stranded and unshielded| 16AWG / 9A

Unit Start-Up

IMPORTANT
Units should be energized 24 hours before unit start-up to prevent compressor damage as a result of slugging.

1. Inspect all factory- and field-installed wiring for loose connections.
2. Verify that the manifold gauge set is connected.
3. Add additional refrigerant charge if required before opening valves and while system is still under a vacuum.
4. Open the liquid and gas line service valves to release the refrigerant charge contained in outdoor unit into the system.
5. Replace the stem caps and tighten to the value listed in “Table 4. Flare Nut Torque Recommendations” on page 13.
6. Check voltage supply at the outdoor unit terminal strip. The voltage must be within the range listed on the unit’s nameplate. If not, do not start the equipment until you have consulted with the power company and the voltage condition has been corrected.
7.  Refer to the included user guide to operate the system using the provided remote control.
8. Visually check for binding of both indoor and outdoor fans.

Adding Refrigerant for Longer Line Set

The outdoor unit is factory-charged with refrigerant. Calculate the additional refrigerant required according to the diameter and the length of the liquid pipe between the outdoor unit and indoor unit connections.
Be sure to add the proper amount of additional refrigerant. Failure to do so may result in reduced performance.
Additional Refrigerant Charge

System Size (KBtu)| Pipe Length (feet / meters)| Amount of Refrigerant to add
---|---|---
12| >25 (7.5)| 0.161 oz/ft (15g/m)

Troubleshooting

See “Error Codes” on page 19 for details on troubleshooting.

Test Run
Pre-Checks

Only perform test run after you have completed the following steps:

• Electrical Safety Checks – Confirm that the unit’s elec-trical system is safe and operating properly
• Refrigerant Leak Checks – Check all flare nut connec-tions and confirm that the system is not leaking
• Confirm that liquid and gas valves are fully open

Procedure

You should perform the Test Run for at least 30 minutes.

1. Connect power to the unit.
2. Press the ON/OFF button on the remote controller to turn it on.
3.  Press the mode button to scroll through the following functions, one at a time:
   • COOL – Select lowest possible temperature
   • HEAT – Select highest possible temperature
4. Let each function run for 5 minutes, and perform the following checks:

Dry Mode Operation (Dehumidification)

Procedure

1. Using the provided wired remote control, press the MODE button and select DRY mode.
2. Press the UP/ DOWN button to select the desired temperature. The temperature setting range is from 62°F (17°C) to 86°F (30°C) in one degree increments.

NOTE : The blower is preset at a low speed and cannot be changed therefore it will get cold and most likely will surpass the temperature setting and will run down to 50°F (10°C) room temperature depending on the room size or other various factors. Also the Follow Me mode does not operate in this mode.

NOTE : In addition, the indoor units do not have a humidistat installed therefore they are unable to determine humidity levels. This product is not recommend as a main source for dehumidification.

Sequence of Operation

When in dry mode operation the unit is actually in cooling mode with a low speed blower operation. Set remote temp to a lower room temp to begin the dry mode operation. The compressor will stop when the room temperature is 50°F (10°C) lower than the temperature setting.
System will not resume unit until room temperature rises above 53.6°F (12°C).

Default Settings
When the system restarts after a power failure, it will default to the factory settings – AUTO mode, AUTO fan, 24°C (76°F). This may cause inconsistencies on the remote control and unit panel. Use your remote control to update the status.

Auto – Restart
In case of power failure, the system will immediately stop. When power returns, the Operation light on the indoor unit will flash. To restart the unit, press the ON/OFF button on the remote control. If the system has an auto restart function, the unit will restart using the same settings.
Louver Angle Memory Function
Some models are designed with a louver angle memory function. When the unit restarts after a power failure, the angle of the horizontal louvers will automatically return to the previous position.
The angle of the horizontal louver should not be set too small as condensation may form and drip into the machine. To reset the louver, press the manual button, which will reset the horizontal louver settings.
The louvers can be in automatic swing function and will swing with in a preset open and close in both heat and cooling. If you chose to position the louvers in one place. see manual mode.

Refrigerant Leak Detection System
In the event of a refrigerant leak, the LCD screen will display “EC” and the LED indicator light will flash.

Manual Operations
This display panel on the indoor unit can be used to operate the unit in case the remote control has been misplaced or is out of batteries.

• MANUAL  – This button selects the mode in the follow-ing order: AUTO, FORCED COOL and OFF.
• FORCED COOL  – In FORCED COOL mode, the Operation light flashes. The system will then turn to AUTO after it has cooled with a high wind speed for 30 minutes. The remote control will be disabled during this operation.
• OFF  – When the panel is turned OFF, the unit turns off and the remote control is re-enabled.

Adjusting Airflow Direction
Manual Swing –  Press Air Direction to put the louver at a desired angle. The louver swings (upward or downward) at a different angle with each press of the button.

The vertical blades are not automatic and can be adjusted manually as shown below. Adjust the louver vertically.

To adjust the horizontal louvers, hold the knob and move the louver. You will find a knob on the left-side and the right-side blades.

How to Clean the Air Filter

The filter prevents dust and other particles from entering the indoor unit. Dust buildup can reduce the efficiency of the air conditioner. For optimum efficiency, clean the air filter every two weeks or more frequently if you live in a dusty area. Replace the filter with a new one if it’s heavily clogged and cannot be cleaned.

1. Open the front panel.
   

2. Remove the Air Filter: Press the clamps on the right and left sides of the air filter down slightly, then pull upward to remove the air filter.
   

Indoor Unit Troubleshooting Codes

Optional Programmable Wired Controller
Programmable
If your chose is to use the programmable wired controller then connect the wired controller to the adapter board’s CN4 connector.

Non-Programmable
This unit is not compatible with the M0STAT61Q-1 non-programmable wired controller.

Read User Manual Online (PDF format)

Download This Manual (PDF format)

Download this manual  >>