64
Proceed as follows to inspect and prepare the unit for initial
start-up:
1. Remove all access panels.
2. Read and follow instructions on all WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with, unit.
3. Make the following inspections:
a. Inspect for shipping and handling damages such as
broken lines, loose parts, or disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections
and on unit base. Detecting oil generally indicates a
refrigerant leak. Leak-test all refrigerant tubing con-
nections using electronic leak detector, halide torch,
or liquid-soap solution.
c. Inspect all field-wiring and factory-wiring connections.
Be sure that connections are completed and tight. Be
sure that wires are not in contact with refrigerant tubing
or sharp edges.
d. Inspect coil fins. If damaged during shipping and han-
dling, carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that condenser-fan blade are correctly posi-
tioned in fan orifice. See Condenser Fan Adjustment sec-
tion for more details.
b. Make sure that air filter(s) is in place.
c. Make sure that condensate drain trap is filled with water
to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose parts
have been removed.
START-UP, GENERAL
Unit Preparation
Make sure that unit has been installed in accordance with installa-
tion instructions and applicable codes.
In addition to the base unit start-up (unit with electro-mechanical
control), there are a few steps needed to properly start-up units
with optional direct digital controls (DDC). The DDC’s Service
Test function should be used to assist in the base unit start-up
and also allows verification of output operation. Controller con-
figuration is also part of start-up. This is especially important
when field accessories have been added to the unit. The factory
pre-configures options installed at the factory. There may also be
additional installation steps or inspection required during the
start-up process.
Additional Installation/Inspection
Inspect the field-installed accessories for proper installation,
making note of which ones do or do not require configuration
changes. Inspect the DDC Alarms for initial insight to any po-
tential issues. Refer to the Controls, Start-up, Operation and
Troubleshooting Instructions manual for the specific DDC. In-
spect the SAT sensor for relocation as intended during installa-
tion. Inspect special wiring as directed below.
Return-Air Filters
Ensure correct filters are installed in unit (see Appendix B —
Physical Data). Do not operate unit without return-air filters.
Outdoor-Air Inlet Screens
Outdoor-air inlet screen must be in place before operating unit.
Compressor Mounting
Compressors are internally spring mounted. Do not loosen or re-
move compressor hold down bolts.
Internal Wiring
Check all electrical connections in unit control boxes. Tighten as
required.
Refrigerant Service Ports
Each unit system has two 1/4-in. SAE flare (with check valves)
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
On 3-phase units with scroll compressors, it is important to be
certain compressor is rotating in the proper direction. To deter-
mine whether or not compressor is rotating in the proper
direction:
1. Connect service gauges to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge
pressure 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. Re-energize to the compressor. Check pressures.
The suction and discharge pressure levels should now move to
their normal start-up levels.
NOTE: When the compressor is rotating in the wrong direction,
the unit will make an elevated level of noise and will not provide
cooling.
Cooling
Set space thermostat to OFF position. To start unit, turn on main
power supply. Set system selector switch at COOL position and
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 on
page 17.
Reset thermostat at a position above room temperature. Compres-
sor will shut off. Evaporator fan will shut off after a 30-second
delay.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
The unit must be electrically grounded in accordance with lo-
cal codes and NEC ANSI/NFPA 70 (American National Stan-
dards Institute/National Fire Protection Association).
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.
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