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Refrigerant Service Ports
Each unit system has two
1
service ports: one on the suction line, and one on the compressor
discharge line. Be sure that caps on the ports are tight.
Compressor Rotation
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature wear and
damage to equipment.
Scroll compressors can only compress refrigerant if rotat-
ing in the right direction. Reverse rotation for extended
times can result in internal damage to the compressor.
Scroll compressors are sealed units and cannot be repaired
on site location.
NOTE: When the compressor is rotating in the wrong direction,
the unit will make an elevated level of noise and will not provide
cooling.
On 3-phase units with scroll compressors, it is important to be cer-
tain compressor is rotating in the proper direction. To determine
whether or not compressor is rotating in the proper direction:
1.
Connect service gages to suction and discharge pressure
fittings.
2.
Energize the compressor.
3.
The suction pressure should drop and the discharge pres-
sure should rise, as is normal on any start-up.
If the suction pressure does not drop and the discharge pressure
does not rise to normal levels:
1.
Note that the evaporator fan is probably also rotating in
the wrong direction.
2.
Turn off power to the unit and install lockout tag.
3.
Reverse any two of the unit power leads.
4.
Reapply electrical power to the compressor.
5.
The suction pressure should drop, and the discharge pres-
sure should rise, which is normal for scroll compressors on
start-up.
6.
Replace the compressor if suction/discharge pressures are
not within specifications for the specific compressor.
Cooling
Set space thermostat to OFF position. To start unit, turn on main
power supply. Set system selector switch at COOL position and
/
-in. SAE flare (with check valves)
4
fan switch at AUTO. position. Adjust thermostat to a setting be-
low room temperature. Compressor starts on closure of contactor.
Check unit charge. Refer to Refrigerant Charge section.
Reset thermostat at a position above room temperature. Com-
pressor will shut off. Evaporator fan will shut off after a
30 second delay.
To shut off unit, set system selector switch at OFF position. Reset-
ting thermostat at a position above room temperature shuts unit off
temporarily until space temperature exceeds thermostat setting.
NOTE: The default value for the evaporator-fan motor on/off de-
lay is 45 seconds. The Integrated Gas Unit Controller (IGC) modi-
fies this value when abnormal limit switch cycles occur. Based
upon unit operating conditions, the on delay can be reduced to 0
seconds and the off delay can be extended to 180 seconds. When
one flash of the LED is observed, the evaporator-fan on/off delay
has been modified.
Ventilation (Continuous Fan)
Set fan and system selector switches at ON and OFF positions, re-
spectively. Evaporator fan operates continuously to provide con-
stant air circulation. When the evaporator-fan selector switch is
turned to the OFF position, there is a 30 second delay before the
fan turns off.
FASTENER TORQUE VALUES
Table 28 — Torque Values
LOCATION
Supply fan motor mounting
Supply fan motor adjustment plate 120 in.-lb (13.6 Nm) ± 12 in.-lb
Motor pulley setscrew
Fan pulley setscrew
Blower wheel hub setscrew
Bearing locking collar setscrew
Compressor mounting bolts
Condenser fan motor mounting
bolts
Condenser fan hub setscrew
56
TORQUE VALUE
120 in.-lb (13.6 Nm) ± 12 in.-lb
(1.4 Nm)
(1.4 Nm)
72 in.-lb (8.1 Nm) ± 5 in.-lb
(0.6 Nm)
72 in.-lb (8.1 Nm) ± 5 in.-lb
(0.6 Nm)
72 in.-lb (8.1 Nm) ± 5 in.-lb
(0.6 Nm)
50 in.-lb (6.2 Nm) — 60 in.-lb
(6.8 Nm)
65 in.-lb (7.3 Nm) — 75 in.-lb
(8.5 Nm)
20 in.-lb (2.3 Nm) ± 2 in.-lb
(0.2 Nm)
84 in.-lb (9.5 Nm) ± 12 in.-lb
(1.4 Nm)
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Troubleshooting
