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CONNECT GROUND AND POWER WIRES

Connect ground wire to ground connection in control box for
safety. Connect power wiring to contactor as shown in Fig. 4.

NOTE:

Use No. 18 AWG (American Wire Gage) color-coded,

insulated (35° C minimum) wire. If thermostat is located more than
100 ft (30.5m) from unit as measured along the control voltage
wires, use No. 16 AWG color-coded wires to avoid excessive
voltage drop.

CONNECT CONTROL WIRING

Route 24-v control wires through control wiring grommet and
connect to brown and blue pigtails supplied in unit splice box. (See
Fig. 5.)
Use furnace transformer, fan-coil transformer, or accessory trans-
former for control power, 24-v/40-va minimum.

NOTE:

Use of available 24-v accessories may exceed the mini-

mum 40-va power requirement. Determine total transformer load-
ing and increase the transformer capacity or split the load with
accessory transformer as required.

Step 6—Compressor Crankcase Heat

When equipped with a crankcase heater, energize heater a mini-
mum of 24 hr before starting unit. To energize heater only, set
thermostat to OFF and close electrical disconnect to outdoor unit.
A crankcase heater is required if the refrigerant tubing is longer
than 50 ft (15.24m).

Step 7—Install Electrical Accessories, If Any

Refer to the individual instructions packaged with the kit or
accessory when installing.

Step 8—Start-Up and Check Charge

To prevent compressor damage or personal injury, observe
the following:
• Do not overcharge system with refrigerant.
• Do not operate unit in a vacuum or at negative pressure.
• Do not disable low-pressure switch.
In scroll compressor applications:
• Dome temperatures may be hot.

To prevent personal injury wear safety glasses, protective
clothing, and gloves when handling refrigerant and observe
the following:
• Back seating service valves are not equipped with Schrader
valves. Fully back seat (counter clockwise) valve stem before
removing gage port cap.
• Front seating service valves are equipped with Schrader
valves.

Do not vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.

1. Fully back seat (open) liquid and vapor tube service valves.

2. Unit is shipped with valve stem(s) front seated and caps

installed. Replace stem caps after system is opened to refrig-
erant flow (back seated). Replace caps finger-tight and tighten
additional 1/6 turn with wrench.

3. Close electrical disconnects to energize system.

4. Set room thermostat at desired temperature. Be sure set point

is below indoor ambient temperature.

5. Set room thermostat to COOL and fan to ON or AUTO mode,

as desired. Operate unit for 15 minutes. Check system
refrigerant charge.

6. Factory charge is shown on unit rating plate. Adjust charge by

following procedure shown on charging tables located on unit.

• 3-phase scroll compressors are rotation sensitive.
• A flashing LED on phase monitor indicates reverse rotation.
(See Fig. 6 and Table 3.)
• This will not allow contactor to be energized.
• Disconnect power to unit and interchange 2 field wiring
leads on unit contactor.

SEQUENCE OF OPERATION

Turn on power to indoor and outdoor units. Transformer is
energized.

On a call for cooling, thermostat makes circuits R-Y and R-G. On
three phase models with scroll compressors, the units are equipped
with a phase monitor to detect if the incoming power is correctly
phased for compressor operation. (See Fig. 5 and Table 2.)If the
phasing is correct, circuit R-Y energizes contactor, starting out-
door fan motor and compressor circuit. R-G energizes indoor unit
blower relay, starting indoor blower motor on high speed.

NOTE:

If the phasing is incorrect, the contactor will not be

energized. To correct the phasing, interchange any two of the three
power connections on the field side.

When thermostat is satisfied, its contacts open, de-energizing
contactor and blower relay. Compressor and motors stop.

If indoor unit is equipped with an off-delay circuit, the indoor
blower can run up to an additional 120 sec to increase system
efficiency.

Fig. 4—Line Power Connections

A96650

FIELD POWER

WIRING

DISCONNECT PER

IEC AND/OR

LOCAL CODES