ECN Forum
Posted By: InspectorE Thousand Amp Fuse - DIY - 10/13/22 11:32 AM
This should be good for about 1000 amps! Unfortunately, the wire isn't and looks like it will fuse out soon...or burn down the house...

https://qph.cf2.quoracdn.net/main-qimg-3140904e27d2382a813e48e0b6e270eb-lq
Posted By: HotLine1 Re: Thousand Amp Fuse - DIY - 10/13/22 07:03 PM
I have seen a few with copper water pipe of the 1/2" and 3/4", on rooftop HVAC units. Usually with a few blown fuses laying around. Have not come upon any pipe nipples yet.

The disconnect in this pic would get a red sticker, unsafe, be shut down at the source of the feeder.
Posted By: Bill Addiss Re: Thousand Amp Fuse - DIY - 10/13/22 11:28 PM
Very Dangerous!

mad
Posted By: gfretwell Re: Thousand Amp Fuse - DIY - 10/14/22 02:42 AM
I am hoping that is just being used as a disconnect and there is OCP somewhere up stream. If so it is just a 110.3(B) but still worth a violation. They do make "Breakers" with about the same over current protection and they are legal (no numbers on the handle). It is just a switch that fits in a breaker slot. I always thought that was dangerous in the hands of the untrained.
Posted By: HotLine1 Re: Thousand Amp Fuse - DIY - 10/18/22 05:37 PM
OK, looking at the pic again, I would def red tag this and do an unsafe notice.

The disconnect is damaged besides the fuse issue. "A" phase will not open! Look carefully as the insulating mechanism that pulls out the cutout is damaged. The spring that tightens the cutout receiver is damaged.
"C" phase also looks like it also has issues, but I cannot enlarge the pic enough.

The conductors appear to have heat issues from the pic. An accident waiting to happen.
Posted By: NORCAL Re: Thousand Amp Fuse - DIY - 11/05/22 11:40 AM
The problem with all poles not being opened when shutting off the switch was not as prevalent in that generation of Cutler-Hammer safety switches, but was quite common in the version it replaced, the insulator would just break, not fail from overheating like the example above.
© ECN Electrical Forums