Look for a U/L or another Nationally Recognized Testing Lab sticker. Switching a neut by itself has been forbidden forever. Some of the Japanese equipt. I've run into has asked to switch both hot & neut.
Look out before you guys kill somebody!!
#6985 - 01/17/0208:39 AMRe: hot fuse on air conditioner caused by broken neutral?
As a maintenance electrician I've seen switched neutrals within UL approved appliances many times. It makes you wonder but there isn't a dern thing you can do about it. If you rewire the machine you've voided the UL. To answer the question ... I only have a "what if": If the current was arching or pulsing to ground at some point near the fuse you may produce heat that is transmitted to the fuse but not necessarily through the fuse. Any signs of arcing or sparking?
#6987 - 01/17/0207:57 PMRe: hot fuse on air conditioner caused by broken neutral?
I've seen this happen a few times at 600v.The fuse element will drop into the silica and turn into a resistor.When you pull out the fuse you shake it and it becomes open.I think the last time it was a CJ 400 amp fuse.