acs 23V26 Packaged Rooftop Units Low Ambient Kit Instruction Manual

©2023

PACKAGED UNITS – KITS

507917-03
10/2023
Supersedes 507917-02

LOW AMBIENT KIT

INSTALLATION INSTRUCTIONS FOR LOW AMBIENT KIT (23V26; 619589-10)
USED ON KGC/KCC300 PACKAGED ROOFTOP UNITS

Shipping and Packing List

Package 1 of 1 contains:

2- Head pressure control (A190)
1- Temperature switch bracket
1- Wiring harness – A190 24V power
1- Wiring harness – A190 to K254
1- Wiring harness – A190 to K255
1- Bag assembly containing:

2-Pressure transducers (A188, A189)
2-Temperature switches (S201, S202)
10-Wire ties
1-Wiring diagram
2-Screws, #8-32 X 1/2 TFS
2-Screws, #8-32 X 1-1/4 TFS

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.

Application

This kit allows low ambient operation to 0°F (-17.8°C) unless otherwise noted in product specifications.

Operation

When ambient temperature drops below 55°F (adjustable), S201 and S202 temperature switches open to de-energize K10 and K150 relay coils. Condenser fans 1, 2, 4 & 5 are de-energized.

Liquid line pressure transducer A188 and A189convert the pressure to an analog signal which is sent to the head pressure controls (A190, A191). The head pressure control provides a variable output which slows Condenser Fan 3 & 6 operation at lower ambient temperatures.

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional installer (or equivalent), service agency or the gas supplier.

Installation

1 – Disconnect all power to unit and open access panels.
2 – Install head pressure controls (A190 & A191) in the control section as shown in figure 1. Secure with screws (provided).
3 – Install the temperature switch mounting bracket onto the mullion. Align the bracket with the 4th screw from the top of the unit; secure with provided screw. See figure 1.
4 – Install the temperature switches onto the bracket.
5 – Using the ICM Omni App, set the head pressure controller as follows:
Probe Type: Pressure
Setpoint: 355 psig
Hard Start: 0.1s
Minimum Voltage Output: 32%
6 – Set heat pump jumper to “CONTROL INPUT”.
7 – Install the pressure transducers on compressor 2 (stg. 2) and compressor 4 (stg. 4). liquid line pressure tap as shown in figure 2.

WARNING

To prevent serious injury or death:
1- Lock-out/tag-out before performing maintenance.
2- If system power is required (e.g., smoke detector maintenance), disable power to blower, remove fan belt where applicable, and ensure all controllers and thermostats are set to the “OFF” position before performing maintenance.
3- Always keep hands, hair, clothing, jewelry, tools, etc., away from moving parts.

HEAD PRESSURE CONTROL AND TEMPERATURE SWITCH LOCATION

FIGURE 1

1. A190
   HEAD PRESSURE CONTROL

2. A191
   HEAD PRESSURE CONTROL

3. K255

4. K254

5. K254, K255
   LOCATION ON REHEAT UNITS

6. TEMPERATURE SWITCH BRACKET

7. OUTDOOR SECTION

8. 4 TH SCREW FROM THE TOP

LIQUID LINE PRESSURE TAP LOCATION

FIGURE 2

1. LIQUID LINE PRESSURE TAPS
   STG. 2
   CIRCUIT 2

2. LIQUID LINE PRESSURE TAPS
   STG. 4
   CIRCUIT 4

3. ROUTE TEMPERATURE SENSOR WIRES THROUGH HOLE IN DIVISION PANEL

DISCONNECT UNIT WIRING FOR S201 & S202 TEMPERATURE SWITCHES
(UNIT CONTROL BOX)

FIGURE 3

1. DISCONNECT WIRES FOR S202
2. DISCONNECT WIRES FOR S201
3. K10

Temperature Switch Wire Connections

1 – Route temperature switch wires through the division panel between the compressor and outdoor coil sections. See figure 2.
2 – Disconnect male and female terminals from wires marked “S201” and “S202” near K10 relay. See figure 3.
3 – Make wiring connections as shown in figure 4.

TEMPERATURE SWITCH WIRING

FIGURE 4

1. DISCONNECT UNIT WIRES MARKED S201
2. DISCONNECT UNIT WIRES MARKED S202
3. S201 TEMPERATURE SWITCH

Low Voltage Wire Connections

Use the 24V harness, provided in this kit, to make transducer wire connections as shown in figure 5.

High Voltage Wire Connections

Note – K254 and K255 relay location is different for reheat units as shown in figure 1.

1 – Connect the harness wire labeled “A190-L1” to the terminal marked “Line 1” on the A190 control.
2 – Connect wires labeled “A190-M” & “A191-M” to the terminal marked “Motor 2” on ICM controllers A190 & A191 as shown in figure 6.
3 – Connect wires labeled “A190-L2” & “A191-L2” to the terminal marked “Line 2” on ICM controllers A190 & A191 as shown in figure 6.
4 – Disconnect factory wires to K254 terminals 4 & 6. Reconnect these wires to the kit harness as shown in figure 6.
5 – Disconnect factory wires to K255 terminals 4 & 6. Reconnect these wires to the kit harness as shown in figure 6.
6 – Make the rest of the K254 and K255 harness connections as shown in figure 6. Refer to the diagram in figure 7.
7 – Make sure all connections are secure.
8 – Bundle wiring and use wire ties to route wiring away from sharp edges.
9 – Place the wiring diagram provided in this kit on the inside of the control door.
10 – Close unit panels and restore power.

24V HARNESS WIRING

FIGURE 5

1. A190
   HEAD PRESSURE CONTROL

2. A188
   STG 1
   PRESSURE TRANSDUCER

3. A191
   HEAD PRESSURE CONTROL

4. A189
   STG 2
   PRESSURE TRANSDUCER

5. BLACK

6. RED

7. STG 1 GREEN

8. GREEN

9. A190-24V-1

10. A190-24V-2

11. TB1-C

12. TB1-R

K254 & K255 HARNESS WIRING

Kit Harness

FIGURE 6

1. Disconnect factory wire labeled “K254-4”

2. K254
   LOW AMBIENT RELAY

3. Disconnect factory wire labeled “K254-6”

4. Was connected to K254-6 relay

5. Was connected to K254-4 relay

6. Motor 2

7. Line 2

8. 120-600 VAC
   Line 1 / Motor 1

9. A190
   HEAD PRESSURE CONTROL

10. OUTDOOR FAN MOTOR 3

11. Disconnect factory wire labeled “K255-4”

12. K255
    LOW AMBIENT RELAY

13. Disconnect factory wire labeled “K255-6”

14. A191
    HEAD PRESSURE CONTROL

15. OUTDOOR FAN MOTOR 6

10 X 8 INCHES

FIGURE 7

DENOTES OPTIONAL COMPONENTS
LIVE VOLTAGE FIELD INSTALLED

WARNING-ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH.
UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES

FOR USE WITH COPPER CONDUCTORS ONLY

DISCONNECT ALL POWER BEFORE SERVICING

IF ANY WIRE IN THIS APPLIANCE IS REPLACED, IT MUST BE REPLACED WITH WIRE OF LIKE SIZE, RATING, INSULATION THICKNESS AND TERMINATION

REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM OVERCURRENT PROTECTION

F10 USED ON Y-VOLT UNITS ONLY

REFER TO INSTRUCTION SHEETS FOR LOW AMBIENT HARNESS INSTALLATION PROCEDURE

WIRING DIAGRAM

538043-02

| 10/23
---|---

COOLING – MSAV

KG/KC C-BOX – 300S – G, J, Y VOLT
LOW AMBIENT KIT

SECTION B

| REV. 2
Supersedes

538043-01

| New Form No.

538043-02

©                                                            Lennox Commercial

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>