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To avoid property damage, personal injury or death due to
fire or explosion, a qualified servicer must investigate the
reason for the rollout protection device to open before
manually resetting the rollout protection device.
Refrigeration System Checks
This unit is equipped with thermal expansion valves.
Ensure the hold-down bolts on the compressor are secure
and have not vibrated loose during shipment. Check that
the vibration grommets have been installed and visually
check all piping for damage and leaks and repair if
necessary. The entire system has been factory charged
and tested, making it unnecessary to field charge. Factory
refrigerant charge is shown on the unit's nameplate.
To confirm charge levels or, if a leak occurs and charge
needs to be added to the system, it is recommended to
evacuate the system and recharge refrigerant to the unit's
nameplate specifications. This unit has been rated in the
cooling mode at the AHRI rated conditions of: indoor (80°F
db/67°F wb) and outdoor (95°F db). While operating at this
condition, the superheat should range from 9°F to 11°F for
each refrigeration circuit measured at the suction service
port located near the compressor.
Start-Up Procedure and Checklist
Begin with power turned off at all disconnects.
1. Turn thermostat system switch to "Cool," and fan
switch to "Auto" and turn temperature setting as high
as it will go.
2. Inspect all registers and set them to the normal open
position.
3. Turn on the electrical supply at the disconnect.
4. Turn the fan switch to the "ON" position. The blower
should operate after a 7 second delay.
5. Turn the fan switch to "Auto" position. The blower
should stop after a 60 second delay.
6. Slowly lower the cooling temperature until the unit
starts. The compressor, blower and fan should now be
operating. Allow the unit to run 10 minutes, make sure
cool air is being supplied by the unit.
WARNING
7. Turn the temperature setting to the highest position,
stopping the unit. The indoor blower will continue to
run for 60 seconds.
8. Turn the thermostat system switch to "OFF" and
disconnect all power when servicing the unit.
Refrigeration Sequence Check
1. 24VAC control voltage is provided by the control
transformer to terminal XS. The control voltage is
passed through any installed safety shutdown devices
such as the smoke detector before providing 24VAC
to terminals ES and R.
2. To simulate a mechanical call for cooling lower the
room cooling setpoint to a value below the current
room temperature. The cooling is energized when the
room temperature is above the setpoint for cooling.
3. UNIT WITH ECONOMIZER OPTION: The
compressor circuit is interlocked through of the
economizer module. If the outdoor air enthalpy
(temperature and humidity) is not suitable for cooling,
the economizer will permit the compressor to be
energized.
4. The blower motor is operated to provide cool supply
air to the space.
5. Compressor contactor closes its contacts to provide
power to the compressor motor. In addition, the
condenser fan motor is energized through the
compressor contactor.
DO NOT TOUCH! DISCHARGE LINE MAY BE HOT!
6. Check that the compressor is operating correctly.
The scroll compressors in these units MUST operate
in the proper rotation. To ensure the compressor
is operating in the correct direction, check the
compressor discharge line pressure or temperature
after the compressor is started.
The discharge pressure and discharge line temperature
should increase. If this does not occur and the compressor
is producing an exceptional amount of noise, perform the
following checks.
7. If the compressor is operating backward, disconnect
the unit power supply and lock it in the "OFF" position.
Switch two leads of the power supply at the unit
Single Point Power Block. Reconnect power and
check for compressor and condenser fan motor
operation.
8. With all safety devices closed, the system will
continue cooling operation until the room temperature
is satisfied.
20
WARNING
BURN HAZARD!
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