– 40 –
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 240 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.
Compressor speed is based on the temperature
set point in conjunction with the speci
fi
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.
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
BROWN
•
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 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
con
fi
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 opening 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.
Compressor operation is extremely smooth and
cool. The compressor exterior may be slightly higher
than room temperature while operating; therefore, it
may be dif
fi
cult to detect a running unit.
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.
