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Re: Transformers
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To: tesla-at-grendel.objinc-dot-com
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Subject: Re: Transformers
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From: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
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Date: Thu, 8 Feb 1996 13:01:25 +1200
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Steve writes...
> What is the best way to try to see if a transformer (pole or potential)
> is good using only a DVOM? Is it just a matter of making sure the
> terminals aren't open circuited, and that the LV and HV sides aren't
> shorted together (assuming they're really not electrically connected),
> or is there more to it than that?
A few ideas from me (NOT an exhaustive list) :
Check the turns ratio using a 50/60Hz signal from a signal generator
Check for o/c windings
Check for pri leakage to case - a megger should be adequate for the
low voltage side
A DVOM measuring in the 10's of MOhms range is OK for a cursory look-
see for pri/sec leakage but not a definitive test where 20kV+ of
isolation is concerned.
A winding resistance check is probably a worthwhile exercise
An idea might be to contact a power utility or transformer company
and find out what tests they do. They probably have a printed schedule
Malcolm