Transformer

Westinghouse would be the first place I'd call ;-)

I don't believe they exist anymore, the Westinghouse name was bought by somebody else and gets slapped on various Chinese consumer goods.

Specialty Transformers in Salt Lake City makes some old Westinghouse designs, they're good guys and might be able to point you in the right direction.

What do you need to know about the transformer? Most things can be figured out by looking at it and taking measurements, and looking at literature for similar products.

James Sweet wrote:

The Reagan/post-Reagan years were a complete switch for that giant of manufacturing:

distribution books and some met their generalized lab machine which, while it demonstrated the theory, as a one size fits all device didn't quite work out as a teaching device (but with modifications helped with a Phd thesis) It appears that Westinghouse expanded beyond their basic strength and lost this core.

I have seen but not followed this thread for quite a while. What is so difficult, I would think anyone who took a first year of electrical ac machinery AND UNDERSTOOD IT would be able to get any important information by taking their own measurements. With good luck, there might even be nameplate information. Westinghouse probably did not not make large numbers of transformers with complicated winding arrangements.

An ohmeter can tell you which terminals are connected by windings. Applying a low voltage to two terminals on one winding and taking measurements with a voltmeter will give you all the winding configuration you need.

If that is not enough, you could go into open circuit (with no load) and short circuit (with full load current) tests. What am I missing?

Bill

You aren't missing anything but the equipment to do this with larger transformers. I believe that this one was in the 5MVA range. where most utilities can cobble together a test setup but may not want to. The nameplate information will give rated voltage current and MVA ratings (which can depend on the approach to cooling) as well as nominal % reactance- nothing more of use.

A reasonable guestimate would be to look up another manufacturer's unit in the same MVA range as nearly all transformers by different manufacturers for a given voltage and MVA level will be in the same ballpark- say 10% impedance (which may be all that is needed). However, there are questions remaining from the original thread- voltages?, polyphase? The manual will include other information that may well be of concern and not readily tested -impulse tests, etc are specialized.

Having said this, my regret is that they are not in the business that was their bread and butter for many years has nothing to do with the original question of this thread.-

OK. My memory was faulty. I incorrectly thought that I had read 5kVA instead of 5MVA. A factor of 1000 might change one's pragmatic approach. :-)

Nevertheless, I would think that any enterprise using transformers of such capability would be able to get sufficient engineering talent together so that USENET, and its vagaries, would not be needed,

Bill

Agreed and the instrumentation as well as the open circuit test would be no problem. The short circuit test might be and one would have to make a guess as to the expected impedance level because you do want a short circuit current at or below the rated current. It would be necessary to then supply the SC test with about 5% (to be safe ) of rated voltage so the options depend on the unspecified rating of the transformer. Voltage control with a variac as done in a university lab is not practical.