Components And Controls; Compressor Crankcase Heat (Cch); High- And Low-Pressure Controls (Hpc And Lpc) - Rheem RA17 Series Installation Instructions Manual

Compressor Crankcase Heat (CCH)

While scroll compressors usually do not require
crankcase heaters, there are instances when a
heater should be added. Refrigerant migration
during the off cycle can result in a noisy start up.
Add a crankcase heater to minimize refrigerant
migration and to help eliminate any start up noise
or bearing wash out.
NOTE: A crankcase heater should be installed if:
• The system charge exceeds the values listed in
the adjacent tables,
• The system is sub ect to low voltage variations,
or

High- and Low-Pressure Controls (HPC and LPC)

HPC and LPC are factory installed on
RA17**AJ2CB. 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 circuit.
The high-pressure control (HPC) is an automatic-
reset which opens near 610 PSIG and closes near
420 PSIG.

COMPONENTS AND CONTROLS

• hen a low ambient control is used for system
operation below 55°F.
All heaters are located on the lower half of the
compressor shell. Its purpose is to drive refrigerant
from the compressor shell during long off cycles,
thus preventing damage to the compressor during
start-up.
At initial start-up or after extended shutdown
periods, make sure the heater is energized for at
least 12 hours before the compressor is started.
(Disconnect switch is on and wall thermostat is off.)
MAXIMUM SYSTEM CHARGE VALUES
RA17
Model
Size
24AJ
36AJ
48AJ
60AJ
The low-pressure control (LPC) is an automatic-
reset which opens near 15 PSIG and closes near
40 PSIG.
CAUTION:
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.
Charge Limit
Compressor Without Crankcase
Model Number Heat (1 Phase)
ZPS20K5E-PFV-130 9.6 lbs.
ZPS30K5E-PFV-130 9.6 lbs.
ZPS40K5E-PFV-130 12 lbs.
ZPS49K5E-PFV-130 12 lbs.
The compressor has
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