Sorry - I have a picture but I can't seem to upload it. A while back there was a thread concerning the type of disconnect that looks like it can accomodate fuses but instead just has two brass or copper tubes. The one in the thread had failed, burnt, melted or whatever.
I came across last one last week whose contacts were corroded. I cleaned them up, popped it back in, amped the unit and all was well until I was called back today. Electric furnace service disconnect, panel breaker ahead and unit breaker after. As soon as I entered the condo I knew what happened, unmistakeable smell of burnt wiring. Thick. Disconnect was toasted.
Two questions (ok three): Is there something about this type of disconnect that lends itself to failure? Do they heat up and become loose or something? Why would they - looks like a regular nonfused disconnect? I called another tech after the first visit and he felt the set up was fine.
Why didn't the breakers before or after the disconnect trip?
How close did I come to burning down a luxury condo complex and ending my very short HVAC career?