CONDENSING UNIT INSTALLATION INSTRUCTIONS Table of Contents

6

Single-Stage Thermostat with 2 Low Voltage Wires to

Remote

Y

A

W1

O Y

G R

B/C G R W1

NOTE: For 2-stage condensing units, refer to the Installation

Instructions supplied with the variable-speed indoor units for field wiring connections.

2-Stage Thermostat with 3 Low Voltage Wires to Remote

System Start-Up

W2 YL0/Y1

Y/Y2 W1

A

G R

DEHUM

TWIN

B

O YLO/YI Y/Y2 B/C G R W1 W2

DEHUM

TWIN

B

Y

C

C

A. Thermostat—single-stage heating with single-stage cooling

B. Furnace or air handler

C. Remote

YLO/YI Y/Y2

C R

C

A. Thermostat—2-stage heating with 2-stage cooling

B. Furnace or air handler

C. OD unit

SYSTEM START-UP

■

■

Power must be supplied to the 18 SEER outdoor units containing ECM motors before the power is applied to the indoor unit. Sending a low-voltage signal without highvoltage power present at the outdoor unit can cause a malfunction of the control module on the ECM motor.

Adequate refrigerant charge for a matching evaporator and

15 ft (4.6 m) lineset is supplied with the condensing unit. If line set exceeds 15 ft (4.6 m) in length, refrigerant should be added at 0.6 oz per foot of liquid line.

IMPORTANT: Open the suction service valve first. If the liquid service valve is opened first, oil from the compressor may be drawn into the indoor coil TXV, restricting refrigerant flow and affecting operation of the system.

NOTE: These are not back-seating valves. It is not necessary to force the stem tightly against the rolled lip.

After the refrigerant charge has bled into the system, open the liquid service valve. The service valve cap is the secondary seal for the valves and must be properly tightened to prevent leaks.

Make sure the cap is clean and apply refrigerant oil to the threads and sealing surface on the inside of the cap. Tighten the cap finger tight, and then tighten an additional

¹⁄₆ of a turn (1 wrench flat), or to the following specification, to properly seat the sealing surfaces.

■

³⁄₈" valve to 5 to 10 in.-lbs

■

³⁄₄" valve to 5 to 20 in.-lbs

■

⁵⁄₈" valve to 5 to 20 in.-lbs

■

⁷⁄₈" valve to 5 to 20 in.-lbs

CAUTION

NOTE: Do not introduce liquid refrigerant from the cylinder into the crankcase of the compressor as this may damage the compressor.

To avoid a possible refrigerant leak, open the service valves until the top of the stem is

¹⁄₈

" (3.2 mm) from the retainer.

CAUTION

To avoid a possible refrigerant leak, open the service valves until the top of the stem is

¹⁄₈

" (3.2 mm) from the retainer.

When opening valves with retainers, open each valve only until the top of the stem is

¹⁄₈" (3.2 mm) from the retainer.

NOTE: To avoid loss of refrigerant, do not apply pressure to the retainer.

When opening valves without a retainer, remove the service valve cap, and insert a hex wrench into the valve stem. Back out the stem by turning the hex wrench counterclockwise. Open the valve until it contacts the rolled lip of the valve body.

1. Break the vacuum by fully opening suction and liquid base valves.

2. Set thermostat to call for cooling.

3. Check indoor and outdoor fan operation and allow system to stabilize for 10 minutes for fixed orifices and 20 minutes for expansion valves.