Reznor PDH Operation Manual PreevA - Manual (Page 25)

Form O-PreevA, P/N 234661R8, Page 25
WARNING
Do not release refrigerant to the atmosphere. When adding or
removing refrigerant, the qualified technician must comply with
all national, state/province, and local laws.
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Step 10 . System Startup
Connect refrigerant pressure gauges and electric meters.
CAUTION: Be sure to connect pressure gauges to the suction and
discharge lines before start-up so that compressor rotation can be
checked immediately. Scroll compressors will be destroyed if al-
lowed to operate in reverse. See Hazard Levels, page 2.
Record the ambient temperature. Adjust the system controller so that a call for cool-
ing exists.
NOTE: If the system has digital controls, outdoor ambient lockouts may prevent
mechanical cooling. Temporarily override lockouts by lowering the cooling setpoint.
(Refer to the digital programmable control instruction manual.) When testing is com-
plete, reset the controller.
Because it is a possible to unknowingly connect 3-phase power in such a way
as to cause the scroll compressor to rotate in reverse, it is very important to
check this on startup.
Immediately at startup, observe the gauges. If the suction pressure rises and
discharge pressure drops, the compressor is operating in reverse and must
be shut down. Turn off the power and switch the 3-phase line voltage wiring
connections before restarting the unit.
(Important NOTE: If allowed to operate for several minutes in reverse, the com-
pressor’s internal protector will trip. If a compressor is repeatedly allowed to restart
and run in reverse, the compressor will be permanently damaged.)
WARNING
Do not apply voltage to the compressor when the plug is removed
or terminals disconnected. See Hazard Levels, page 2.
Crankcase Heater
Connect the crankcase heater. The crankcase heater is energized continuously and
is extremely important to proper compressor operation and long life.
The crankcase heater must be energized for at least 24 hours before starting the
unit or after a power outage of more than 8 hours. Be sure to disable reheat controls
before turning on power to warmup crankcase heater.
CAUTION: Crankcase heater must be allowed to warm up for at
least 24 hours prior to startup. Disable reheat controls before
turning on power to warmup crankcase heater. See Hazard Levels,
page 2.
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Step 9. Charge the Reheat Pump Circuit (R410A refrigerant
only.)
Follow the instructions below to charge the circuit. R410A refrigerant MUST BE
charged as a LIQUID.
NOTE: Outdoor temperature must be between 70-95°F (21-35°C) for verifying
superheat and subcooling. If temperature is not within this range, consult the factory
service department before charging.
Check the rating plate for the reheat circuit charge. Charge the refrigerant slowly
through the gauge port on the liquid line. R410A refrigerant must be charged as a
liquid. R410A refrigerant cylinders are rose colored (pink) and have a dip tube for
charging liquid from an upright position. If there is no dip tube, verify that the refriger-
ant is R410A and turn the cylinder upside down.