New GFI with a Dead Short

[mkgrady]

I turned on a new circuit that included a feed to a brand new P&S GFI. The breaker tripped immediatley. I went to a JB and isolated the part of the circuit that had the short and went to work trying to figure out how to replace the piece of romex. I assumed somebody ran a screw into the wire. I finally thought to make sure the short was not internal to the GFI and to my surprise it was. Anybody else ever run into this?

 

[Dennis Alwon]

Nope-- never saw a gfci trip the overcurrent protective device.

 

[jeremysterling]

I turned on a new circuit..(and t)he breaker tripped immediately. Anybody else ever run into this?

What I quoted of you I've experienced many times with brand new SQD QOB breakers with no actual fault. I always cycle these breakers several times prior to commissioning. Are you sure your GFCI actually has a fault or could it be first time jitters for the breaker?

 

[GoldDigger]

Anybody else ever run into this?

Was the date of manufacture Jan 1?
Did you just return the GFCI or tear it apart to see what the failure was?

 

[p real]

i have not seen a gfci ever trip a breaker before itself, but every single p and s tr gfi that i put in, if you set it first, and then energize it, it immediately trips and you hear a little momentary buzzing at that second between it being energized and it tripping, almost like a fuse link that burns out to show if it has ever been energized because it onlydoes it the first time you energize a brand new one. Maybe your little fuse didnt burn out like it was sposed to... Anybody else noticed this? It does it on every single one, but only the pand s ones.

 

[jumper]

Was the date of manufacture Jan 1?

Why would this matter?:?

 

[sparkyrick]

I turned on a new circuit that included a feed to a brand new P&S GFI. The breaker tripped immediatley. I went to a JB and isolated the part of the circuit that had the short and went to work trying to figure out how to replace the piece of romex. I assumed somebody ran a screw into the wire. I finally thought to make sure the short was not internal to the GFI and to my surprise it was. Anybody else ever run into this?

I had a service call a few months ago in a commercial kitchen to fix a problem with a dead short on a circuit. Turned out to be a P&S GFI failing as a dead short. No, it wasn't new, but it wasn't used that often either, looked almost new. No external signs of charring or melting either, it just failed. And no, I didn't bother to take it apart to see why it failed.

 

[mkgrady]

I didn't check the date of manufacture of the gfi receptacle. I returned it this morning and did not take it apart. I will ask the supply house guy if he will give it back and I will try to take it apart.

I have noticed the P&S gfi recepts do have a weird buzzing that sometimes goes on when you first turn it on. I don't remember a pattern to when it happens but I will start to pay attention to that.

You guys have confirmed to me that a shorted gfi recept is pretty rare out of the box. Thanks to all.

 

[George Stolz]

Seems to me I remember tracking down the same problem once. I don't remember the event.

I've also seen GFCIs that had no power at the face of the device when energized, but worked perfectly on the load side.

I guess that's why we hot check!

 

[kwired]

i have not seen a gfci ever trip a breaker before itself, but every single p and s tr gfi that i put in, if you set it first, and then energize it, it immediately trips and you hear a little momentary buzzing at that second between it being energized and it tripping, almost like a fuse link that burns out to show if it has ever been energized because it onlydoes it the first time you energize a brand new one. Maybe your little fuse didnt burn out like it was sposed to... Anybody else noticed this? It does it on every single one, but only the pand s ones.

I don't know for certain, but I think the reason they trip is because of newer listing requirements for miswiring protection. There is some kind of latching relay that must have power when you reset it to remain latched. If it is reset with no power applied it will trip upon energization. This way if line/load are reversed it will not latch when resetting, and they are likely leave the factory in a tripped condition meaning power needs applied before they will reset. I have kind of come to this conclusion on my own and it is not something I can say I definitely am certain about. I do not know exactly what causes the buzzing sound, but have heard it myself many times.