Weird looking fuse

[Tainted]

I went to survey a building and found service switches that have a very thin piece of copper acting like a fuse.

Just wondering what are these called?

If the fuse is blown, is there a way to replace it? Would it be extremely difficult or impossible to get a replacement fuse of this kind?

 

[Eddie702]

Not sure looks like it has an amp rating on it though

 

[Tainted]

Not sure looks like it has an amp rating on it though

It does have it. It said 1200 amps.

 

[petersonra]

Are you sure it is a fuse? Might be a shunt resistor for measuring current.

If it is a shunt resistor it will likely have another marking on it like 100 mV. This would indicate 100 mVolt drop at 1200 Amps.

 

[LarryFine]

Are you sure it is a fuse? Might be a shunt resistor for measuring current.

If it was, there would be meter wires.

 

[petersonra]

If it was, there would be meter wires.

Maybe the meter was never installed. It does not look like anything I have seen before.

 

[Fred B]

looks like a fuse link similar to this bussman

 

[Tainted]

Maybe the meter was never installed. It does not look like anything I have seen before.

CT compartment is above the switch. So it’s not what you think

 

[Tainted]

looks like a fuse link similar to this bussman
View attachment 2570515

Do they make one that’s 1200 amps or more?

 

[jim dungar]

Very old open style overload fuse. Definitely not current limiting.
When it opens, the melted metal and combustion products will be everywhere in the switch.

 

[electrofelon]

That's wild, never heard of those before for LV applications. They do typically use a similar thing called a isolating link in series with the bayonet fuses in pad Mount transformers:

Isolation Link(CHIL) - Chardon Group

Product Code: CHIL The Chardon Isolation Link is used in series with bayonet type expulsion fuses to provide extra protection during re-fusing operations. Isolation links are not fuses and do not have an interrupting rating. During a low impedance transformer failure, the isolation link will...

www.chardongroup.com

 

[Fred B]

Do they make one that’s 1200 amps or more?

Very old open style overload fuse. Definitely not current limiting.
When it opens, the melted metal and combustion products will be everywhere in the switch.

That I think is why the newer ones for the higher ratings are more like an enclosed fuse to prevent it from flying all over the enclosure.

 

[ptonsparky]

It's pretty obvious that location has not been subject to a blown fuse.

 

[kwired]

looks like a fuse link similar to this bussman
View attachment 2570515

I opened up an 1800 amp fuse one time, had several parallel links similar looking to that inside all was encased in silica granules.

 

[tortuga]

Looks like a old Bussmann WHA-D-1200 'Open link' Fuse.
There is some interesting history there.
Easy to remember the part number becasue your like what da heck is that?

Service Equipment questions

Hey guys, I have the following 2 questions: 1. I'm sure the answer is yes, but just in case there's a code nuance that i'm unaware of: are you allowed to pull single phase service entrance conductors from a service end box (service end box is the NYC nomenclature for the 'service point') that...

forums.mikeholt.com

 

[Jraef]

It does have it. It said 1200 amps.

Bussman WHA-D-1200 open link fuse. Very old school. The one in the OPs pic is slightly different maybe due to age of brand.


Oops, didn't see Tortuga's post.