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b. Inspect for oil at all refrigerant tubing connec-
tions and on unit base. Detecting oil generally
indicates a refrigerant leak. Leak--test all refri-
gerant tubing connections using electronic leak
dete ctor, halide torch, or liquid--soap solution.
c. Inspect all field--wiring and factory-- wiring con-
nect ions. Be sure that connections are completed
and tight. Be sure that wires are not in cont act
with refrigerant 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 a re correctly
positioned in fan orifice. See Condenser--Fan
Adjustment section 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
installation instructions and applicable codes.
Gas Piping
Check gas piping for leaks.
UNIT OPERATION AND SAFETY HAZARD
Failure to foll ow this warning could result in personal
injury or death.
Disconnect gas piping from unit when leak testing at
pressure greater than 1/2 psig. Pressures greater than
1/2 psig will cause gas valve damage resulting in
hazardous condition. If gas valve is subjected to
pressure greater than 1/2 psig, it must be replaced
before use. When pressure testing field--supplied gas
piping at pressures of 1/2 psig or less, a unit connected
to such piping must be isola ted by manually closing
the gas valve.
!
WARNING
Return--Air Filters
Make sure correct filters are installed in unit (see
Appendix II -- Physical Data). Do not operate unit without
return--air filters.
Outdoor--Air Inlet Scr eens
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 two 1/4” SAE flare (with check
valve s) 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 com pressor is rotating in the proper
direction. To determine whether or not compressor is
rotating in the proper direction:
1. Connect service gauges to suction and discha rge pres-
sure 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 t he wrong
direc tion, 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 below room temperature.
Compressor starts on closure of contactor.
Check unit charge. Refer to Refrigerant Charge section.
Reset thermostat at a position above room temperature.
Compressor will shut off. Evaporator fan will shut off
afte r a 30--second delay.
To shut off unit, set system selector switch at OFF
position. Resetting t hermostat at a position above room
temperature shuts unit off temporarily until space
temperature exceeds thermostat setting.
Main Burners
Main burners are factory set and should require no
adjustment.
To check ignition of main burners and heating controls,
move the r mostat setpoint above room temperature and
verify that the burners light and evaporator fan is
energized. Check heating effect, then lower the thermostat
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