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Fig. 25 — Filter Installed On Outdoor Air Hood
PRE-START-UP
WARNING: Failure to observe the following warn-
ings could result in serious personal injury:
1. Follow recognized safety practices and wear pro-
tective goggles when checking or servicing refrig-
erant 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 have been disconnected.
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
refrigerant system is under pressure.
6. Do not use torch to remove any component. Sys-
tem contains oil and refrigerant under pressure.
To remove a component, wear protective goggles
and proceed as follows:
a. Shut off all power to unit.
b. Reclaim refrigerant to relieve all pressure from
system using both high- and low-pressure ports.
c. Cut component-connecting 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.
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, 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. If refrigerant leak is de-
tected, see Refrigerant Leaks section on page 31.
c. Inspect all field- and factory-wiring connections. Be
sure that connections are completed and tight.
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 is positioned cor-
rectly in fan orifice. Blades should clear fan motor
and fan orifice ring.
b. Make sure that air filters are in place. (See Table 1.)
Do not operate unit without return-air filters.
c. Make sure that condensate drain pan and trap are
filled with water to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose parts
have been removed.
e. Make sure outdoor-air inlet screens are in place.
5. Compressors are internally spring mounted. Do not loosen
or remove compressor holddown bolts.
6. Each unit system has 4 Schrader-type service ports: one
on the suction line, one on the liquid line and two on
the compressor discharge line. Be sure that caps on the
ports are tight.
Unit is now ready for initial start-up.
I. COMPRESSOR ROTATION
On 3-phase units, it is important to be certain the scroll com-
pressor 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 pres-
sure 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 (060 and 072 only) is prob-
ably also rotating in the wrong direction.
2. Turn off power to the unit.
3. Reverse any two of the unit power leads.
4. Turn on power to the compressor.
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 cooling.
—17—
START-UP
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