GE PSH23PGR Series, Technical Service Manual

Page: 26 / 62

– 26
• 3°F to 5°F above refrigerator set point -
medium speed.
• 5.5°F to°7 F above refrigerator set point - high
speed.
Note: The compressor will run at medium speed
if the freezer temperature is 20°F or more above
the setpoint.
The use of 3-phase power eliminates the need
for the PTCR relay, capacitor, and individual
start and run windings; therefore, the start,
run and common pins found on conventional
compressors are not applicable on this 3-phase
model. Compressor pin functions are identical
and compressor lead wire confi guration is of no
importance. A resistance of 9
Ω
to 11
Ω
should be
read between any 2 of the 3 pins. Should an open
occur in the compressor winding or should one
of the compressor lead wires become open or
disconnected, the inverter will stop voltage output
to the compressor.
High compressor torque enables the compressor
to start against high pressure in the sealed
system. When power has been disconnected
from an operating unit, the high torque will enable
the compressor to start immediately upon power
restoration.
Compressor and sealed system operation is
extremely smooth and cool. The compressor
exterior may be room temperature while
operating; therefore, a running unit may be
diffi cult to detect.
To verify that the compressor is running:
Disconnect power from the unit and place a hand
on the compressor. Reconnect power and feel for
a vibration when the compressor tries to start. It
may take up to 8 seconds before the compressor
attempts to start.
Note:
When ordering a replacement compressor,
order both the compressor and inverter.
Replace the compressor fi rst. If, after
compressor installation, the compressor fails
to start, replace the inverter.
When servicing the compressor, it is important
to dress the wiring to keep low voltage DC
wiring and 120 VAC wiring separate.
•
•
Inverter Compressor
Caution: Do not attempt to direct-start the
compressor. The compressor operates on a
3-phase power supply. Applying 120 VAC to the
compressor will permanently damage the unit. It
is not possible to start the compressor without an
inverter.
The compressor is a reciprocating, variable
speed, 4-pole type. It operates on 3-phase, 80 to
230 VAC within a range of 57 to 104 Hz.
Note: Certain voltmeters will not be able to read
voltage output or frequency from the inverter.
Compressor wattages at various speeds are:
• LOW - 65 watts
• MED - 100 watts
• HIGH - 150 watts
The compressor is controlled by the inverter,
which receives its signal from the main control
board. Varying the frequency to the inverter
changes the compressor speed.
TA
B
1
J15-1 J15-2
AC
BROWN
BLACK
BROWN
COMPRESSOR
BLACK
BLUE
ORANGE
WHITE
RED
INVERTER
ORANGE
WHITE
RED
10
10
10
Main Control
Board
Compressor speed is based on the temperature
set point in conjunction with the specifi c cabinet
temperature. Speeds are selected according to
the following cabinet temperatures, with freezer
temperature being the primary:
• 7°F to 19.5°F above freezer set point = high
speed.
• 4.5°F to 6.5°F above freezer set point =
medium speed.
• 1°F to 4°F above freezer set point = low
speed.
• 1°F to 2.5°F above refrigerator set point = low
speed.