The cheapest way to fix the problem?

batcave · Jan 22, 2022

So, This is the Main disconnect for a Panel that provides Heat to units.
I shut off the Main. Worked on the panel. Went back to energize the Main Disconnect and this is What happened.

littlespark · Jan 22, 2022

“Holy arcing, Batman!”

And that’s why it’s known as the “bang test”

Sox how much was running through that when you closed it?

batcave · Jan 23, 2022

littlespark said:
“Holy arcing, Batman!”

And that’s why it’s known as the “bang test”

Sox how much was running through that when you closed it?

800 Amps
575 AC

pc1966 · Jan 23, 2022

If I understand those photos, the insulated "fingers" are actuating the knife switch aspect and one has failed mechanically, leading to the actuating bar shorting out the supply?

pc1966 · Jan 23, 2022

Looking at the snapped off bit I would be wary of what it is made of, as it looks a lot like the asbestos/cement roof tiles. I might be wrong, but be very careful not to breath in any dust just in case.

I can't see any option to repair it with glue, etc. I really doubt you would get enough strength and if it failed when supposed to be isolating, that is potentially a fatal fault. You might be able to find a scrapped board of the same sort to find some recoverable part, but equally I would be a bit worried that the other ones might fail the same way!

Megawatt · Jan 23, 2022

batcave said:
So, This is the Main disconnect for a Panel that provides Heat to units.
I shut off the Main. Worked on the panel. Went back to energize the Main Disconnect and this is What happened.

It looks to me like the stabs are loose and it has been pulled and thrown back in while being under a heavy load. It needs to be replaced

Megawatt · Jan 23, 2022

batcave said:
So, This is the Main disconnect for a Panel that provides Heat to units.
I shut off the Main. Worked on the panel. Went back to energize the Main Disconnect and this is What happened.

If that is one of the old bulldog switches, they are notorious for breaking

freddo · Jan 24, 2022

Looking at the photos, it really doesn't look like the most robust of designs!

batcave · Jan 27, 2022

pc1966 said:
If I understand those photos, the insulated "fingers" are actuating the knife switch aspect and one has failed mechanically, leading to the actuating bar shorting out the supply?

yes sir, indeed. Thank god the cover was closed and the lock hinges in place, or else well i dunno id be fried or damage goods.