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Re: MOT pig limiters



I have  two 1.5 KVA transformer -at- 8kv and I tried using a MOT to limit
current but limited current too much.  I used one for each transformer.  Is
there any certain type of MOT that is needed?  There are many types out
there.

Thanks,
Brian
-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Saturday, September 12, 1998 5:25 PM
Subject: Re: MOT pig limiters


>Original Poster: Bert Hickman <bert.hickman-at-aquila-dot-com>
>
>Tesla List wrote:
>>
>> Original Poster: "Bill the arcstarter" <arcstarter-at-hotmail-dot-com>
>>
>> It was written:
>> >Bill,
>> >
>> >I haven't tried it, but I would guess that you would use a microwave
>> oven
>> >transfromer as a current limiting inductor just as you would a welder.
>> Leave
>> >it intact, short the outputs and run the current to be limited through
>> the
>> >primary - and the shunts should come into play.
>> >
>> >Ed Sonderman
>>
>> Yes.  Thats also what we've been doing, but in light of my recent MOT
>> saturation tests (haven't yet eval'd a MOT with a shorted-out secondary)
>> it looks like we are getting more impedance due to the primary winding's
>> resistance (0.5 ohms measured) , as opposed to inductive limiting.  I
>> don't think that's really what we need, or is it?
>>
>> I do know that my particular MOT would draw over 30 amps at 120V with
>> the sec shorted out.  My 20 amp line fuses didn't like it much.
>>
>> More experiments are needed! Where's my 0.1 ohm 100W resistor at... :)
>>
>> I have a 10KVA 19900 (only 125 lb supposedly) pig coming to my doorstep
>> late next week!  Woo Hoo!
>>
>> Late friday Paul stumbled into a few (6 or 8?) 5KVA 14400 units, about
>> the size of a 5-gallon bucket, at a scrapyard.  Is there any good way to
>> ID these as to their PCB/no-PCB oil status, or is it a random risk?
>>
>> If I can get them for the right price, is there an interest on the
>> list??
>>
>> -Bill the arcstarter
>> Starting arcs in Cinci, OH
>> http://www.geocities-dot-com/CapeCanaveral/Hangar/6160
>>
>> ______________________________________________________
>> Get Your Private, Free Email at http://www.hotmail-dot-com
>
>Bill,
>
>Usually, there will be a "No PCB's" sticker on the case somewhere. The
>other option is to pop the lid on them, and take a look and a sniff. If
>the fluid looks and smells like mineral oil, you should be OK. If these
>have been in hard service, the oil may be a darker color, and may have a
>bit of a "burnt" odor, but avoid purchasing any with any signs of carbon
>in the oil.
>
>Transformer PCB's have a definate yellower color, and the odor is
>definately different NOT anything like mineral oil - it's more
>"solvent-like". Also, transformer PCB's are almost twice as heavy as
>mineral oil - mineral oil has a specific gravity of around 0.88, while
>PCB's are around 1.55. Finally, there's the burn test - PCB's will not
>burn. Period. Torture mineral oil enough and you can make it burn.
>
>Hope this helps,and happy hunting! I may be interested in one of these
>if they look good and contin no PCB's...
>
>-- Bert --
>
>
>
>