LENNOX 23V25 Low Ambient Kit Instruction Manual

LENNOX 23V25 Low Ambient Kit

INSTALLATION INSTRUCTIONS FOR LOW AMBIENT KIT (23V25; 619589-09) USED ON KGC/KCC240 PACKAGED ROOFTOP UNITS

Shipping and Packing List

Package 1 of 1 contains:

• 1- Head pressure control (A190)
• 1- Temperature switch bracket
• 1- Wiring harness – A190 24V power
• 1- Wiring harness – A190 to K254
• 1- Bag assembly containing:
  • 1-Pressure transducer (A188)
  • 1-Temperature switch (S201)
  • 10-Wire ties
  • 1-Wiring diagram
  • 2-Screws, #8-32 X 1/2 TFS
  • 2-Screws, #8-32 X 1-1/4 TFS

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 temperature switch opens to de-energize K10 relay coil. Condenser fans 1 & 3 are de- energized.

Liquid line pressure transducer A188 converts the pressure to an analog signal which is sent to the head pressure control (A190). The head pressure control provides a variable output which slows Condenser Fan 2 & 4 operation at lower ambient temperatures.

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 HVAC installer or equivalent, service agency, or the gas supplier.

Installation

1. Disconnect power to unit and open access panels.

2. Install the head pressure control (A190) in the control section as shown in figure 1. Secure with self-tapping 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 switch onto the bracket.

5. Set the head pressure control as follows:
   Setpoint: 355 psig
   Hard Start: Min.
   Cut-out Speed: Set to 5th marker from minimum Heat Pump Pin set to: N.O.

6. Install the pressure transducer on compressor 2 liquid line pressure tap as shown in figure 2.
   
   To prevent serious injury or death:

7. Lock-out/tag-out before performing maintenance.

8. 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.

9. Always keep hands, hair, clothing, jewelry, tools, etc., away from moving parts.

HEAD PRESSURE CONTROL AND TEMPERATURE SWITCH LOCATION

LIQUID LINE PRESSURE TAP LOCATION

TEMPERATURE SWITCH WIRING

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” near K10 relay. See figure 3.
3. Make wiring connections as shown in figure 4.
   TEMPERATURE SWITCH WIRING
   

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

1. Disconnect factory wires to K254 terminals 4 & 6. Reconnect these wires to the kit harness as shown in figure 6.
2. Check the voltage to the unit. Connect the harness wire labeled “A190-L1” to EITHER the 460-600VAC terminal OR 120-277VAC terminal.
3. Make the rest of the K254 harness connections as shown in figure 6. Refer to the diagram in figure 7.
4. Make sure all connections are secure.
5. Bundle wiring and use wire ties to route wiring away from sharp edges.
6. Place the wiring diagram provided in this kit on the inside of the control door.
7. Close unit panels and restore power.

24V HARNESS WIRING

K254 HARNESS WIRING

UNIT WIRING

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

538041-02

| 10/22
---|---
COOLING – MSAV
KG/KC C-BOX – 240S – G, J, Y VOLT LOW AMBIENT KIT
SECTION B| REV. 1
Supersedes
538041-01| New Form No.
538041-02

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