Help getting welder wired in!

[Inspector507]

I know that you are a professional electrician but I am suprised that you agreed with this. Forget about the welder itself what if you have something shorted maybe something as simple as a mouse chewing the wire or something shorting in the welder. My impression of 12 gauge wire is that it could flame on before it tripped that 50 amp breaker. I would never ever ever consider running a wire with less ampacity than the breaker that feeds it.

There's a big difference between an overload on a breaker and a fault to ground or a line to line fault. Most likely that 50A breaker is rated to work somewhere between 10,000 and 22,000 amps short-circuit current. Now that'll cook your hotdogs for ya

It's not that I merely agree with it, the engineers at Hobart, the engineers at UL who tested it and the code making panels of the NEC are a heck of a lot smarter than I am.
You can always go better than recommended. And if that's what you want to do, go for it. Poor old fishpick was just asking if he was missing something and I answered his question based upon what the real experts determined was safe.

 

[hitekcountry]

There's a big difference between an overload on a breaker and a fault to ground or a line to line fault.

I don't understand that statement, an over current condition is an over current condition no mater what the cause. And any wire is limited by it's cross sectional area as to the amount of current it can carry. The purpose of a breaker/fuse is to limit the current for a specific wire size, It's the amount of current that maters, what causes the current is irrelevant. So if you're going to use 12 gauge wire then use a 20 amp breaker or at most 25 but not a 50 amp.

Most likely that 50A breaker is rated to work somewhere between 10,000 and 22,000 amps short-circuit current. Now that'll cook your hotdogs for ya

10,000 to 22,000 Amps!! .. No way!! I think you meant to say watts.

 

[Inspector507]

I don't understand that statement, an over current condition is an over current condition no mater what the cause. And any wire is limited by it's cross sectional area as to the amount of current it can carry. The purpose of a breaker/fuse is to limit the current for a specific wire size, It's the amount of current that maters, what causes the current is irrelevant. So if you're going to use 12 gauge wire then use a 20 amp breaker or at most 25 but not a 50 amp.



10,000 to 22,000 Amps!! .. No way!! I think you meant to say watts.

Yes the purpose of a breaker/fuse is to limit the current/load it can carry for a definate time period. It also has a limit as to the fault current rated in AIC or Amps Interrupting Current. It is the amount of current allowed during a fault to ground or fault line to line. And yes I meant Amps not watts.

 

[hitekcountry]

And yes I meant Amps not watts.

So a 50 amp breaker is designed to trip at between 10,000 and 22,000 amps???

 

[SnowRidge]

So a 50 amp breaker is designed to trip at between 10,000 and 22,000 amps???

I believe he means it will briefly handle that much current without damage, while it opens up. It will trip at a nominal 50 amps. It will take longer to trip with a slight overload than it will with a large overload.

 

[Inspector507]

So a 50 amp breaker is designed to trip at between 10,000 and 22,000 amps???

Yes 10,000-22,000 AIC or Amps Interrupting Current, or short circuit current, same thing. They could be rated higher than that. I've seen them over 65,000 AIC.
It's not even related to overload amps. 50A overload is 50A.
What I was responding to is a hypothetical mouse chewing into a wire or a welder shorting out causing a fault not an overload.

There's a big difference between an overload on a breaker and a fault

 

[hitekcountry]

I believe he means it will briefly handle that much current without damage, while it opens up. It will trip at a nominal 50 amps. It will take longer to trip with a slight overload than it will with a large overload.

What it can handle without damage and what current it will trip at are two totally different things.

 

[hitekcountry]

So to answer Gemini5362's example a mouse chews through the wire and you have a wire to wire short, you're saying it ok to have a 12gauge wire protected with a 50A breaker?

 

[SnowRidge]

What it can handle without damage and what current it will trip at are two totally different things.

Which is exactly what I said.

 

[hitekcountry]

Which is exactly what I said.

Yes I know.

What I was Commenting on was the statement by the inspector that

"That 50a breaker is rated to work somewhere between 10,000 and 22,000amps short-circuit current"

That sounds like it is designed to trip at the level more than that it is able to survive at the level.