Service Manual

Silicone Grease on Power Transistor/Diode Bridge SiUS041638E
111 Trial Operation and Field Settings
5. Silicone Grease on Power Transistor/Diode Bridge
Outline
Apply the specified silicone grease to the heat radiation part of a power transistor/diode bridge when
you replace an outdoor unit PCB. The silicone grease encourages the heat radiation of a power
transistor/diode bridge.
Details 1. Wipe off the old silicone grease completely.
2. Apply the silicone grease evenly. See the illustrations below for examples of application.
3. Tighten the screws of the power transistor/diode bridge.
4. Make sure that the heat radiation parts are firmly contacted to the radiation fin.
Note: Smoke emission may be caused by bad heat radiation when the silicone grease is not
appropriately applied.

OK: Evenly applied

NG: Not evenly applied

NG: Foreign matter is stuck.
(R22541)
Power transistor
(or diode bridge)
Silicone grease
Radiation
fin
PCB
(R21866)
Foreign matter
(R21867)