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Re: Ground Fault Interupters and RFI filters
---------- Forwarded message ----------
Date: Mon, 29 Sep 1997 21:45:11 -0600 (MDT)
From: Chip Atkinson <chip-at-pupman-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Ground Fault Interupters and RFI filters
Greetings,
I know for a shocking fact that the RFI filters bleed a little electricity
to ground. I was working on my power cabinet, which was not connected to
ground (yet), but was connected to the 220V mains. The cabinet is all
metal, including the start and stop buttons that close the contactors. I
had it all wired, pushed the start button and just about jumped to the
ceiling. It took me about 2 hours to debug the thing because my
multitester would show infinite resistance (DC ohms), but when I plugged
it in, I would measure a voltage of between 80 and 120v (working from
memory here). It wasn't until I was nearly done that I realized that the
DC from the ohmmeter would not go through the caps. Once I realized that
the problem was from the filters, I connected the ground and the problem
went away.
Chip
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Chip Atkinson
http://www.pupman-dot-com and http://bhs.broo.k12.wv.us/homepage/chip/info.htm
--- If I can't fix it, I can fix it so it can't be fixed --
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On Sun, 28 Sep 1997, Tesla List wrote:
>
>
> ---------- Forwarded message ----------
> Date: Sun, 28 Sep 1997 22:10:34 -0500 (CDT)
> From: Richard Wayne Wall <rwall-at-ix-dot-netcom-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Ground Fault Interupters and RFI filters
>
> 9/29/97
>
> I recently added a 30 A circuit breaker/GFI to my power cabinet. It's
> placed before the main contactor and variac. Following the variac
> there is a 100 A RFI filter. Without the main power transformer
> connected, the GFI trips when power is applied. It still trips when
> either the neutral or hot is disconnected and the other remains
> connected. Removing the RFI filter stops the GFI tripping. I replaced
> the RFI filter with two 200 A EMI filters on both the neutral and hot
> line. Same thing happens as with the RFI filter.
>
> Has anyone had this experience with GFIs and RFI filters? Anyone know
> what the mechanism is?
>
> RWW
>