Precautions For Exchange Of 4 Way Valve A Assy; Fusible Plug; Location Of Fusible Plug - Fujitsu Airstage VR-II Series Service Manual

18. Precautions for exchange of 4 way valve A Assy

4 way valve A assy includes a " Fusible plug ". Be aware of the followings when repairing.

1. Fusible plug

Plug made of fusible alloy.
When a temperature inside equipment extreamly rises by fire disaster,
fusible alloy of plug will melt and make a hole.
And refrigerant inside equipment will be discharged
for preventing a burst of pressure vessel coming from pressure increase.

2. Location of Fusible plug

<Precautions>
(1) When a temperature reaches to 167 degrees F (75 degrees C),
fusible alloy in the center of plug will melt and make a hole.
(2) When you replace a fusible plug, make sure to replace
"4 way valve A assy" extensively.
(3) When you replace a "4 way valve A assy", make sure to
drape a wet rag on it for keeping it cool.
If fusible alloy melts and makes a hole from heat,
vacuum drawing and refrigerant charging will be not available.
Also refrigerant inside will be discharged swiftly.
(4) When you weld pipes or parts near fusible plug, make sure to
insulate plug and pipes from fire and guard a plug using
a wet rag.
(5) Do not unclench a fusible plug. Airtightness will be compromised.
If a plug is unclenched
(In order to keep high airtightness, it is controlled strictly
by tightening torque, seal tape and Loctite.)
06-13
"4 way valve A assy"
( P/N 9379052092 )