Daikin RXL25G2V1B, Service Manual

Page: 286 / 294

SiENBE04-925_A Application of Silicon Grease to a Power Transistor and a Diode Bridge
Trial Operation and Field Settings 271
3. Application of Silicon Grease to a Power
Transistor and a Diode Bridge
Applicable
Models
All outdoor units using inverter type compressor for room air conditioner.
When the printed circuit board (PCB) of an outdoor unit is replaced, it is required that silicon
grease (*1) is certainly applied to the heat radiation part (the contact point to the 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.
„
Wipe off the old silicon grease completely on a radiation fin.
„
Apply the silicon grease evenly to the whole.
„
Do not leave any foreign object such as solder or paper waste between the power transistor
and the radiation fin, and also the diode bridge, and the radiation fin.
„
Tighten the screws of the power transistor and the diode bridge, and contact to the radiation
fin without any gap.
<Example>
(R9056)
Take out a PCB
Not applied. Paper waste
NG : Foreign object
OK : Evenly applied
silicon grease.
NG : Not evenly
applied
Diode bridge
(Diode bridge, Rectifier stack, etc.)
Power transistor
(TRM, TPM, IGBT, IPM, SPM, etc.)
SIENBE04-925_A_FRONT.pdf 286 24/02/2011 13:54:20