240v Welder powered by portable generator?

kencaz · 05-22-2008, 01:52 AM

Quote:

Originally Posted by BigJimmy

Disagree. In a ground fault, i.e. fault between ungrounded/hot conductor and ground (as opposed to a phase to phase fault and yes I know that residential is split phase, thank you), the current flows back to the source via the EGC.

What? Do you really think that? Ground faults are cleared at the transformer through the Grounded Conductor NOT the EGC.

Your house has 4 wires: 2 Un-grounded conductors, 1 grounded conductor, and 1 Equipment Grounding Conductor.
Your house is fed 3 wires: 2 Un-grounded conductors, and 1 grounded conductor.

Please tell me how ground faults are cleared through the EGC?

Quote:

You're confusing main bonding jumper, grounding electrode conductor and equipment grounding conductor.

What did you read that made you think I was confused?

Quote:

GFCI's work on the "current in=current out" principle. If the current leaving is in excess of 5mA of that returning, the device will trip. It doesn't need to know where the fault current went nor does it require an EGC to do so. Read article 406. Why do you think it is acceptable to replace older, ungrounded receptacles with newer grounding types that are fed from a GFCI w/o an EGC??

I know how GFCI's work. That is why I brought it up in post 8 when "jrclen" was so sure the OP had a proper ground without really knowing.

Quote:

No, there are some appliances that require both 240 and 120 inputs (i.e. they do not have an internal transformer to create the 120 from the 240).

That has nothing to do with what I said...

KC

jrclen · 05-22-2008, 10:02 AM

Quote:

Originally Posted by kencaz

Your house is fed 3 wires: 2 Un-grounded conductors, and 1 grounded conductor.

Please tell me how ground faults are cleared through the EGC?

Through the main bonding jumper.

Quote:

What did you read that made you think I was confused?

your posts

My purpose in this thread was to give the OP a clear concise answer to his question that he was not getting, not to debate nor argue with you. I accomplished that.

If you wish to debate electrical theory or code I will be more than happy to do that in the proper forum. This is a DIY site where people come for answers. It is not a forum to show the world how much (or how little) knowledge one possesses.

The OP is happy, I am happy, and I am finished with this thread.

kencaz · 05-23-2008, 04:56 PM

Quote:

Originally Posted by jrclen

Through the main bonding jumper.

Great! That's good that you know that...

Quote:

My purpose in this thread was to give the OP a clear concise answer to his question that he was not getting, not to debate nor argue with you. I accomplished that.

If you wish to debate electrical theory or code I will be more than happy to do that in the proper forum. This is a DIY site where people come for answers. It is not a forum to show the world how much (or how little) knowledge one possesses.

Well, yes you gave the OP and answer, however, I questioned it and you could not accept that... You assumed in your post (#6) that the OP had a safe ground path which you did not, (and still do not), know.

I am not debating with you... code is not up for debate. My only point (I don't know where you thought it was confusing) was to make sure the OP had a safe electrical connection.

For others in a similar situation here is the reference:

250.30(A)(1) Bonding - Effective Fault Current Path. To provide the low impedance path necessary to clear a ground-fault on a separately derived system, the metal parts of electrical equipment must be bonded together (equipment grounding conductor) and connected to the system grounded conductor (X0 Terminal). The bonding jumper used for this purpose must be sized in accordance with Table 250.66

DANGER: Failure to provide a low impedance ground-fault path (no neutral-to-case bond) for the separately derived system can create a condition where a ground-fault (line-to-case fault) cannot be removed. The result is that all electrical metal parts, as well as the building structure will remain energized with dangerous line voltage if a ground-fault (line-to-case fault) occurs.

I may be beating a dead horse here! but there it is.

KC

loyd · 03-30-2009, 05:20 PM

Quote:

Originally Posted by MRJChannahon

I just bought a 240v MIG welder and want to run it off my 7K gasoline generator.
The welder has a 6-50P plug (three prong), drawing 20 amps or less and the generater has an L14-30R receptacle. The generator L14-30 ground connection is wired into a line leading to the frame & ground lug on the generator and is NOT connected to the generator's AC neutral wire.

My question is whether to wire the welder's ground prong to to "neutral" or the "ground" prong on the L14-30? If I'm correct/safer to wire it to the "ground", do I then have to ground the generator via plumbing or an earth rod to be able to use the welder?

Thanks!

I want the answer to this queston,also.

InPhase277 · 03-30-2009, 06:19 PM

Quote:

Originally Posted by loyd

I want the answer to this queston,also.

I've read the responses to the original post, and it appears everyone was misunderstanding everyone else. But to answer the question, you connect the ground terminal of the welder to the ground terminal of the receptacle. IF the generator is properly wired, the ground and neutral will be bonded inside the generator.

The OP's generator was not properly bonded, and that's where the confusion began. A plug tester should show everything as normal and properly wired. Connecting the generator to a ground rod or water pipe is not necessary for portable applications.