Daikin FTXS30HVJU, Service Manual

Page: 192 / 202

SiUS04-924 Other Considerations
Others 185
1.3 Application of Silicon Grease to the 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.

Completely wipe off the old silicon grease from the heat radiation fin.

Evenly apply the silicon grease to the whole diode bridge and power transistor.

Do not have any foreign object such as solder or paper waste between the power transistor, the
diode bridge, and the heat radiation fin.

Firmly tighten the screws of the power transistor and the diode bridge to ensure 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 waste
OK : Evenly applied
silicon grease. NG : Not evenly
applied NG : Foreign object.
(R9056)