"Asimov" wrote in message
...
Hi,

I was troubleshooting my sister's donated old Viking window AC which
....
I've heard of AC compressors locking up if not used for a very long
time. I'm guessing the oil drains out of the bearings. It seems it

+ Unusual for a sealed unit. It does need to sit in the normal working
position for a while before it is fired up.

....
I have a couple of question's about the defrost contact. Is it simply
a fail-safe device or is it needed to turn off the compressor as part
of normal operation? Are these pretty generic?

+ You don't want to freeze up the evaporator, so it's needed IMO.

This one clips onto the cold end return and made by Klixon (Made in
USA) # 20425F21-439-780 F56-3.0 6CV Not too sure about the F56-3.0 as
it was smudged. It was held in place by a thick tape ressembling
mastic, some kind of thermal insulation?

+ Possible tape that has dissolved over time? Double sided foam tape?

N