Service Monitor Board (Smb; Inverter Power Module (Ipm - GE ASH220NCDWA Service Manual

Service Monitor Board (SMB)

The SMB has important features including operational DIP switches, error code display, compressor speed, and diagnostic
capabilities.
The SMB is connected to the PCB via connections CN-2 and CN-3.
1
The SW1 DIP switches are OFF (default position for normal operation).
2
The digital display will indicate operating frequency of the compressor when no
3
error code is present, or will flash an error code if present.
A solid green LED indicates that the A, B, C, D or E unit is successfully
4
communicating with the outdoor unit.

Inverter Power Module (IPM)

2U & 3U
The Inverter Power Module generates 3-phase VDC
1
power to operate the variable speed compressor. The
compressor is connected to the IPM via terminals U, V
and W.
A Reactor Coil is connected to the IPM at terminals
2
RI and RO. The Reactor Coil will filter electrical noise
generated at high frequency operation that could
cause damage to the compressor windings.
IPM generates a large amount of heat during operation.
3
This heat is transfered to a heat sink behind the board,
then mixed with the outdoor air. The Tm temperature
sensor protects the IPM from excessive temperatures.
4U
The Inverter Power Module generates 3-phase
1
variable VDC power(60V-230V) to operate the
variable speed compressor. The compressor is
connected to the IPM via terminals U, Vand W.
A Reactor Coil is connected to the IPM at terminals
2
LI and LO.The Reactor (spec is 5mH,25A/5mH);
the reactor is one part of the PFC(power factor
chopper circuit). Its main function is to boost
the DC bus voltage with the PFC switches IGBT.
The PFC circuit will improve the power factor
and reduce electromagnetic noise caused by
harmonics.
IPM generates a large amount of heat during
3
operation. This heat is transferred to a heat sink
behind the board, then mixed with the outdoor air.
The Tfin temperature sensor is used to protects
4
the IPM from excessive temperatures.
Components
Topic Title
1
OUTDOOR TECHNICAL OVERVIEW
3
2
1
4
1
2
4
3
2
3
B-3