SiUS04-904 Other Considerations
256 Other Considerations
1.3 Application of Silicon Grease to Power Transistor and
Diode Bridge
Applicable
Models
All outdoor units using inverter type compressor for room air conditioner.
When the printed circuit board of an outdoor unit is replaced, it is required that silicon grease (*1) is
applied to the heat radiation part (the contact point to the heat radiation fin) of the power transistor
and diode bridge.
*1: Parts number of the silicon grease – 1172698 (Drawing number 3FB03758-1)
Details The silicon grease is an essential article for encouraging the heat radiation of the power transistor
and the diode bridge. Applying the paste should be implemented in accordance with the following
instruction.
Remark: There is the possibility of failure with smoke in case of bad heat radiation.
ompletely wipe off the old silicon grease heat radiation fin.
venly apply the silicon grease to the whole.
Do not have any foreign object such as solder or paper waste between the power transistor, the
diode bridge and the heat radiation fin.
irmly tighten the screws of the power transistor and the diode bridge contact to the heat
radiation fin without any gap.
<Example>
Take out a PCB
Diode bridge
(Diode bridge, Rectifier stack, etc.)
Power transistor
(TRM, TPM, IGBT, IPM, SPM, etc.)
Not applied.
Paper wastage
OK : Evenly applied
silicon grease.
NG : Not evenly
applied
NG : Foreign object.
(R9056)