How to determine winding material?
How to determine winding material?
(OP)
Referring to a GE 34.5-4160 3000kva substation transformer. I cannot determine the winding material. The nameplate does not indicate. I searched into company archives.It was ordered in 1951 and installed in 1952. The prints or bid specs do not indicate. Is there any posibility that there are aluminum windings in a unit of this vintage?
Any insight is appreciated.
Any insight is appreciated.






RE: How to determine winding material?
But I suspect that if you have a serial number from the nameplate, GE can track the information down. They have found information on much older equipment for me.
David Castor
www.cvoes.com
RE: How to determine winding material?
I agree on the date but unfortunately I need to prove this.
RE: How to determine winding material?
RE: How to determine winding material?
RE: How to determine winding material?
Thanks.
RE: How to determine winding material?
Reasons why I think it is copper:
1. Size is the overriding practical reason for using copper. Utility transformers are designed with very large short circuit tolerances, because of the size of the grid and the magnitude of the current flow in the event of a fault. The windings have to be both large enough to handle those currents and strong enough to withstand the mechanical loads they impose. Aluminum's (volumetric) conductivity and its strength are much lower than coppers, so an aluminum transformer that matched the kVA rating of, say, a 400-MVA copper unit would be huge! It would be too large to transport, and utility or substation transformers are not items that can be assembled on site. All of the transformers we make are copper-wound; even so, we have to ship the larger ones by rail. Size can also be important in transformers installed in high-rise buildings, where space is often at a premium.
2. Utilities did try aluminum back in the 1970s. Interest rates and inflation were high then, and first-cost considerations got in the way of conventional wisdom. Some utilities bought aluminum-wound transformers because they were initially less costly. They ended up having many more failures than with copper transformers, and, as a result, utilities won't touch aluminum today for transformers in our size range.
RE: How to determine winding material?
The type of query raised by linehand is raised quite often and I used to suggest to utilities to insist for a rating plate with all new transformers indicating the net weight of copper/aluminum, silicon steel, steel and oil contained in the transformer so that at the end of life, owner is aware of the salvagable value.