User`s manual

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21
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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
connections using electronic leak detector, halide
torch, or liquid-soap solution. If refrigerant leak is
detected, see Service, Refrigerant Leaks section on
page 33.
c. Inspect all field- and factory-wiring connections.
Be sure that connections are completed and tight.
Ensure that no electrical wiring is in contact 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 gas supply has been purged, and
that all gas piping has been checked for leaks.
b. Make sure that condenser-fan blade is correctly
positioned in fan orifice. Blades should clear fan
motor.
c. Make sure that air filters are in place.
d. Make sure that condensate drain pan and trap are
filled with water to ensure proper drainage.
e. Make sure that all tools and miscellaneous loose
parts have been removed.
5. Compressors are internally spring mounted. Do not
loosen or remove compressor holddown bolts. On size
150 units, remove the tiedown bands that hold the
compressors together.
6. Each unit system has 4 Schrader-type gage 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.
High Flow Valves
Located on the compressor hot gas and suction tubes are
High Flow Valves. 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.
Unit is now ready for initial start-up.
START-UP
I. HEATING SECTION START-UP AND ADJUSTMENTS
Do not jumper any safety devices when operating the unit.
Ensure that burner orifices are aligned properly. Unstable
operation may occur when the burner orifices in the mani-
fold are misaligned.
Follow the lighting instructions on the heating section opera-
tion label (located inside the burner access door) to start the
heating section.
NOTE: When lighting the unit for the first time, perform the
following additional steps: If the gas supply pipe was not
purged before connecting the unit, it will be full of air. It is
recommended that the ground joint union be loosened and
the supply line be allowed to purge until the odor of gas is
detected. Never purge gas lines into a combustion chamber.
Immediately upon detection of gas odor, retighten the union.
Allow 5 minutes to elapse, then light unit in accordance with
Checking Heating Control Operation section below.
A. Checking Heating Control Operation
Start and check the unit for proper heating control operation
as follows: (Also see furnace lighting instructions located
inside the burner access panel.)
1. Turn on unit electrical supply and manual gas valve.
2. Set system switch selector at HEAT position and fan
switch at AUTO. or ON position. Set heating temper-
ature lever above room temperature.
3. The induced-draft motor will start immediately.
4. After a call for heating, the main burners should light
within 5 seconds. If the burner does not light, then
there is a 22-second delay before another 5-second
try. If the burner still does not light, the time delay is
repeated. If the burner does not light within 15 min-
utes there is a lockout. To reset the control, break the
24-v power to W1. See note.
NOTE: The default value for the evaporator-fan motor ON/
OFF delay is 45 seconds. The Integrated Gas Unit Controller
(IGC) modifies this value when abnormal limit switch cycles
occur. Based upon unit operating conditions, the ON delay
can be reduced to 0 seconds and the OFF delay can be
extended to 180 seconds.
When one flash of LED is observed, the evaporator-fan ON/
OFF delay has been modified. If the limit switch trips at the
start of the heating cycle during the evaporator ON delay,
the time period of the ON delay for the next cycle will be 5
seconds less than the time at which the switch tripped.
EXAMPLE: If the limit switch trips at 30 seconds, the evapo-
rator-fan ON delay for the next cycle will occur at 25 seconds.
To prevent short-cycling, a 5-second reduction will only occur
if a minimum of 10 minutes has elapsed since the last call for
heating.
The evaporator-fan OFF delay can also be modified. Once the
call for heating has ended, there is a 10 minute period dur-
ing which the modification can occur. If the limit switch trips
during this period, the evaporator-fan OFF delay will
increase by 15 seconds. A maximum of 9 trips can occur,
extending the evaporator-fan OFF delay to 180 seconds. To
restore the original default value, reset the power to the
unit.
5. The evaporator fan will turn on 45 seconds after a
call for heating.
6. The evaporator fan will turn off 45 seconds after ther-
mostat temperature has been satisfied.
7. Adjust airflow to obtain a temperature rise within
the range specified on the unit nameplate.
To shut off unit, set system selector switch at OFF position
or set heating selector lever below room temperature.
DANGER: Do not purge gas supply into the com-
bustion chamber. Do not use a match or other open
flame to check for gas leaks. Failure to adhere to this
warning could result in an explosion causing personal
injury or death.
CAUTION: Complete the required procedures
given in Pre-Start-Up section on page 20 before start-
ing unit.