43
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.
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-wiring and factory-wiring connec-
tions. Be sure that connections are completed and
tight.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
4. Verify the following:
a. Make sure that condenser-fan blades are correctly
positioned in fan orifice. Refer to Condenser-Fan
Adjustment section on page 48 for more details.
b. Make sure that air filters are 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.
e. Make sure that the start-up checklist has been per-
formed and filled out.
NOTE: Ensure wiring does not contact any refrigerant tubing.
START-UP
Unit Preparation —
Make sure that unit has been in-
stalled in accordance with these installation instructions and
applicable 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 screens
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 refrigerant sys-
tem has 4 Schrader-type service gage ports: one on the suction
line, one on the liquid line, and 2 on the compressor discharge
line. Be sure that caps on the ports are tight.
High Flow Valves —
Two high flow refrigerant valves
are located on the compressor hot gas and suction tubes. Large
black plastic caps distinguish these valves with o-rings located
inside the caps. These valves can not be accessed for service in
the field. Ensure the plastic caps are in place and tight or the
possibility of refrigerant leakage could occur.
Compressor Rotation —
On 3-phase units, it is impor-
tant to be certain the scroll 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 pres-
sure 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. Turn on power to the unit.
The suction and discharge pressure levels should now move
to their normal start-up levels.
NOTE: When the compressor is rotating in the wrong direc-
tion, the unit makes an elevated level of noise and does not
provide heating or cooling.
Cooling —
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 below room
temperature. Compressor starts on closure of contactor.
Check unit charge. Refer to Refrigerant Charge section on
page 48.
Reset thermostat at a position above room temperature.
Compressor will shut off.
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 and properly
tagged.
4. Relieve all pressure from system before touching or
disturbing anything inside terminal box if refrigerant
leak is suspected around compressor terminals. Use
accepted methods to recover refrigerant.
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 to unit and install
lockout tag.
b. Relieve all pressure from system using both
high and low-pressure ports. Use accepted
methods to recover refrigerant.
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.
Compressor damage will occur if rotation is not immedi-
ately corrected.
