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Re: Variac arcing = kickback? (fwd)





---------- Forwarded message ----------
Date: Thu, 15 Jan 1998 04:51:15 EST
From: Mark S Graalman <wb8jkr-at-juno-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: Variac arcing = kickback? (fwd)

 Do you have a GOOD grounded line filter
in the AC line between the variac and the 
transformers?

Mark Graalman


On Wed, 14 Jan 1998 20:01:09 -0700 (MST) Tesla List <tesla-at-pupman-dot-com>
writes:
>
>
>---------- Forwarded message ----------
>Date: Wed, 14 Jan 98 21:46:42 -0500
>From: Adam <absmith-at-tiac-dot-net>
>To: tesla list <tesla-at-pupman-dot-com>
>Subject: Variac arcing = kickback?
>
>
>I decided to see what would happen if I added more transformer power 
>to 
>my project, and I got disturbing arcing in the variac.  The variac is 
>an 
>18 general radio 120V variac, which was feeding the two 9kV 60mA 
>transformers on my project without incident.  There is 8 feet of 14-3 
>cable between the variac and the project, and the ground wire in this 
>bundle is unused.
>
>When I added transformer number three and fired up the coil, I got 
>power 
>arcs between the variac's moving brush assembly and variac housing 
>above 
>it.  The arc is jumping about 3/16" so I'm pretty sure it's not just 
>the 
>normal 140V there!  What ever is sparking across this gap is followed 
>by 
>a power arc from the mains, which melted a bit from both parts of the 
>variac.  Somethings seems to be kicking back from the neons.  This 
>only 
>seems to happen when there is a breakout from the toroid.  I am 
>naturally 
>concerned for all appliances in the house, and I would like to correct 
>
>this problem ASAP.
>
>What's going on here?
>
>-Adam
>
>