Comfort PRL-series, Installation Instructions Manual

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11.0 HIGH AND LOW PRESSURE CONTROLS
11.0 (HPC AND LPC)
These controls keep the compressor from operating in pressure ranges which can
cause damage to the compressor. Both controls are in the low voltage control cir-
cuit.
High pressure control (HPC) is an automatic-reset which opens near 610 PSIG and
closes near 420 PSIG.
The low pressure control (LPC) is an automatic-reset which opens near 15 PSIG
and closes near 40 PSIG.
NOTE: HPC and LPC are monitored by the Comfort Control
2
System™ . See
Section 12.0.
11.1 Evacuation Procedure
Evacuation is the most important part of the entire service procedure. The life and
efficiency of the equipment is dependent upon the thoroughness exercised by the
serviceman when evacuating air and moisture from the system.
Air in the system causes high condensing temperatures and pressure, resulting in
increased power input and non-verifiable performance.
Moisture chemically reacts with the refrigerant and oil to form corrosive hydrofluoric
and hydrochloric acids. These attack motor windings and parts, causing breakdown.
After the system has been leak checked and proven sealed, connect the vacuum
pump and evacuate system to 500 microns. The vacuum pump must be connected
to both the high and low sides of the system through adequate connections. Use
the largest size connections available since restrictive service connections may lead
to false readings because of pressure drop through the fittings.
IMPORTANT: Compressors (especially scroll type) should never be used to evacu-
ate the air conditioning system because internal electrical arcing may result in a
damaged or failed compressor.
With thermostat in the “Off” position, turn the power on to the furnace and the heat
pump. Start the heat pump and the furnace with the thermostat. Make sure the
blower is operating.
!
CAUTION
THE COMPRESSOR HAS AN INTERNAL OVERLOAD PROTECTOR. UNDER
SOME CONDITIONS, IT CAN TAKE UP TO 2 HOURS FOR THIS OVERLOAD
TO RESET. MAKE SURE OVERLOAD HAS HAD TIME TO RESET BEFORE
CONDEMNING THE COMPRESSOR.