Re: Big Variacs but are they useable?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

HI Matt,

At 07:06 PM 4/25/2003 -0400, you wrote:
>Hi All,
>I have been looking for some Big Variacs on eBay to control a 5KVA 240 V 
>piglet, but I suspect that what it not being said in these ads may make 
>these unsuitable for TC work. Knowledgeable input requested.
>
>This one
>http://cgi.ebay-dot-com/ws/eBayISAPI.dll?ViewItem&category=4665&item=2525401964&rd=1
>Says 220 volts 7.5 KVA. It also says 220/50 which might imply 220 V in and 
>50 V out.  The picture is just fuzzy enought for the meter scale to be 
>unreadable. Heavi-Duty Electric Corp does not show up in my web search.

I am not sure what that is.  Best not to get odd things unless you are 
sure.  Shipping may be like $50 to 100 so it is hard just to get it and see 
even if the price is great.  You may be able to write the sellers and ask 
questions if needed but may sellers don't no much about these things.  More 
pictures are best...


>The second one
>http://cgi.ebay-dot-com/ws/eBayISAPI.dll?ViewItem&category=11806&item=2524988160&rd=1
>is rated 0-560V 30A.. But what if it is used on 240 V single phase system?

That is a big 480V variac but it is taped well so you could use it for 
anything.  You can always use a variac at less that the rated voltage, but 
never more.



>The last one
>http://cgi.ebay-dot-com/ws/eBayISAPI.dll?ViewItem&category=11772&item=2526194124&rd=1
>says:
>"This Staco 2510-3 Variable Autotransformer / Power Supply appears to be 
>in good cosmetic condition. 240 V input 60 Hz 0-280V output, 25 Amps, 12.1 
>KVA."

That is a great thing there.  You get a nice case, meters, and a few 
breakers with it.  Probably remove much of the electronic stuff.  Not that 
you will have to pay shipping "also" on this.  That $10 is just to pack it 
up.  Probably a 150+++ pound item.


>But 240V -at- 25A is only 6KVA  Also the meters on the unit only go 0-15 Amp, 
>which doesn't make sense unless we are talking 3-phase system.

This is definitely a three phase setup. But you can use it for two and 
single phase.  Not sure what the meters were meant to do.  The variac may 
have been 5 times larger than what was needed for the original use (common).


>   Are any of these useable/modifiable? I don't want to spend big bucks 
> for a "boat anchor".

Not sure what is in the first one.  In general, if it is a "240 volt" type 
variac with say a 25 amp rating, it will work fine.  The last unit you list 
actually has three variacs in it that can be split apart. Sort of like mine:

http://hot-streamer-dot-com/temp/NewMag/0417-02.jpg

That thing weighs 110 pounds!  Be ready to pay some big shipping fees.

Cheers,

         Terry


>Thanks,
>
>Matt D.
>
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