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#127137 - 05/08/01 12:31 PM 240 V GFCI
Anonymous
Unregistered


Can a two-pole 240 V GFCI detect a ground fault that draws equal amounts of leakage current (e.g., 1.0000 A) from both poles?



[This message has been edited by Dspark (edited 05-08-2001).]

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#127138 - 05/08/01 03:32 PM Re: 240 V GFCI
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2342
Loc: West Virginia
If you wired it as per the diagram, you'd probably kill someone.

But this was mentioned in the other thread...
_________________________
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Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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#127139 - 05/08/01 04:27 PM Re: 240 V GFCI
Anonymous
Unregistered


I'm hoping that Bill fixes the image.
The diagram, I think, will show how the manufacturer wires it.

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#127140 - 05/08/01 08:49 PM Re: 240 V GFCI
Bill Addiss Offline
Member

Registered: 10/07/00
Posts: 4196
Loc: NY, USA
Wiring Diagram Fixed!

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#127141 - 05/09/01 03:21 AM Re: 240 V GFCI
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
ok, thanks Bill...

now can someone explain this??


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#127142 - 05/09/01 05:50 AM Re: 240 V GFCI
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2342
Loc: West Virginia
The way I understand it is that all three conductors pass through the coil, and the current should balance to zero under normal operation. When a fault occurs, there is an imbalance that is detected by the coil and opens the line.

I was thinking before that it would take one coil for each pair (Line "A" to Ground, Line "B" to Ground, Line "A" to Line "B") but I'm mistaken.

As far as getting deeper into how they work... Better let Scott handle it!

_________________________
-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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#127143 - 05/09/01 12:23 PM Re: 240 V GFCI
Anonymous
Unregistered


That's right about how it works in a nutshell.

But I am not clear on whether a symmetrical fault to earth would be detected.

Such a fault is improbable in a hot tub. But I want to know whether it would be detected, if, for instance, a 240 V floor outlet were filled with Pepsi causing a symmetrical fault to ground on both poles.

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#127144 - 05/09/01 12:37 PM Re: 240 V GFCI
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Dspark;
i never heard of a "symetrical fault" , but theoretically, if both conductors climbed the trip curve equally..???>>>

that would be the pepsi challenge

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#127145 - 05/09/01 01:07 PM Re: 240 V GFCI
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Well everyone, if the leakage current to ground was exactly equal from both Ungrounded conductors and at the same time, that would not trip the device!!

It would be similar to someone grabbing both lines [L1 and L2], then getting the ever loved 240 VAC barbeque. The device would not see that as an inbalanced current, so no trip.

Kind of sucks, doesn't it?

Scott SET
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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#127146 - 05/09/01 02:34 PM Re: 240 V GFCI
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
yeah, ouch....
but in the practical world, the probability is slim.
So a good point of discussion is the noodle, gotta have it , straight 240V or not right?

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