[AMPS] re: UTC cg-308 transformer used in FW bridge circuit

[gdaught6@leland.Stanford.EDU]

Bob wrote,

> I have a heavy UTC transformer with a designation (I believe) of CG-308 with
> taps for 7000, 6000, and 4800 vct. I intend to use the 4800 volt tap in a
> full wave bridge configuration in order to get approximately 6000 vdc (under
> load) for my 4-1000A amp. I read with some concern the feedback about the
> UTC S-47 transformer and the cautions not to use a FW bridge circuit with
> this model, because the center tap is intended to be operated at ground
> potential. Do the same reservations apply to my UTC CG-308? Thanks.

According to my UTC catalog (60's vintage) the CG308 should be run 
with the CT grounded.  If the model number has a "W" suffix, then the 
bridge configuration with an ungrounded CT is ok.  According to my 
version of the catalog, there wasn't a "CG308W" but there were CG305W 
and CG311W.  By the way, the "CG" designates "Commercial Grade" with 
a continuous rating (CCS rather than ICAS).

73,

George T. Daughters, K6GT

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