Service and Parts Manual (2018, 2019, 2020, 2021, 2022)

78 PB
WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation. Extreme care must be used, if it
becomes necessary to work on equipment with
power applied.
Failure to do so could result in serious injury or
death.
WARNING
HIGH PRESSURE HAZARD
Sealed Refrigeration System contains refrigerant
and oil under high pressure.
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with refrigerants.
Failure to follow these procedures could
result in serious injury or death.
Figure 705 (Compressor Windings)
COMPONENT TESTING
Compressor Checks
DC
INVERTER
&
R U( )
S V( )
CONTROLLER
T W( )
POWER
OVERLOAD PROT ECTION
Gain access to compressor and IPM PCB (Inverter
Board) by removing chassis from wall. Refer to
Figure 5xx
1) Disconnect terminals R(U), S(V), and T(W) from
the compressor.
Resistance Test.
2) Set Ohm meter to the lowest scale and check
continuity between pins R(U), S(V), and T(W).
At room temperature (70°- 95°F) the resistance
should be approximately 2.2 ohms. The Ohm values
will change signicantly at different temperatures.
This does not indicate that the compressor wind-
ings are faulty. A reading of open (innity), or a
signicant difference in the resistance between the
windings does indicate that the compressor wind-
ings are faulty.
3) Check for continuity from between pins R(U) to
ground, S(V) to ground, and T(U) to ground)
The compressor windings are faulty if the there is
continuity from the compressor windings to ground.
4)Common signs compressor is faulty:
• Compressor motor lock.
• Discharge pressure value approaches static
pressure value .
• Compressor motor winding abnormality.
Note:
• Don’t put a compressor on its side or turn over.
• Assemble the compressor quickly after remov-
ing the plugs. Prolonged exposure will damage
the internal components of the compressor
• Ensure wiring is correct before operating.
Reverse operation will permanently damage
the compressor.
• Electric Reactor
Common Problems:
• Sound abnormality
• Runs in a sporadic rhythm.