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PRE-START-UP
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, CAU-
TION, 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
connections using electronic leak detector, halide
torch, or liquid-soap solution.
c. Inspect all field- and factory-wiring connections.
Be sure that connections are completed and tight.
Be sure that wires are not in contact with refriger-
ant tubing or sharp edges.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that condenser-fan blade are correctly
positioned in fan orifice. See Condenser-Fan
Adjustment section on page 34 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
Unit Preparation —
Make sure that unit has been in-
stalled in accordance with installation instructions and applica-
ble codes.
Return-Air Filters —
Make sure correct filters are in-
stalled in unit (see Table 1). 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 remove compressor hold-
down bolts.
Internal Wiring —
Check all electrical connections in
unit control boxes. Tighten as required.
Refrigerant Service Ports —
Each unit system has
3 Schrader-type service ports: one on the suction line, one on
the liquid line, and one on the compressor discharge line. Be
sure that caps on the ports are tight. Two additional Schrader
valves are located under the high-pressure and low-pressure
switches, respectively.
HIGH FLOW REFRIGERANT VALVES — Two high flow
valves are located on the hot gas tube coming out of the com-
pressor and the suction tube going into the compressor. Large
black plastic caps identify these valves. These valves have
O-rings inside which screw the cap onto a brass body to pre-
vent leaks. No field access to these valves is available at this
time. Ensure the plastic caps remain on the valves and are tight
or the possibility of refrigerant leakage could occur.
Compressor Rotation —
On 3-phase units with scroll
compressors, it is important to be certain compressor is rotating
in the proper direction. To determine whether or not compres-
sor 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 pres-
sure does not rise to normal levels:
1. Note that the evaporator fan (006 and 007 only) is proba-
bly also rotating in the wrong direction.
2. Turn off power to the unit, tag disconnect.
3. Reverse any two of the unit power leads.
4. Reenergize to the compressor. Check pressures.
The suction and discharge pressure levels should now move
to their normal start-up levels.
Failure to observe the following warnings could result in
serious personal injury:
1. Follow recognized safety practices and wear protec-
tive goggles when checking or servicing refrigerant
system.
2. Do not operate compressor or provide any electric
power to unit unless compressor terminal cover is in
place and secured.
3. Do not remove compressor terminal cover until all
electrical sources are disconnected.
4. Relieve all pressure from system before touching or
disturbing anything inside terminal box if refrigerant
leak is suspected around compressor terminals.
5. Never attempt to repair soldered connection while re-
frigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To remove
a component, wear protective goggles and proceed as
follows:
a. Shut off electrical power and then gas to unit.
b. Reclaim refrigerant to relieve all pressure from
system using both high- and low-pressure ports.
c. Cut component connection tubing with tubing
cutter and remove component from unit.
d. Carefully unsweat remaining tubing stubs
when necessary. Oil can ignite when exposed
to torch flame.