transformer
transformer
(OP)
problem that I had at work was I lost 1 of my 12470 to 480 transformers on the pole well I had another set in the power center after 12470 steped to 4160 so 4160 in it was hook wye with 5 taps on the primary most i could get out of it was 365 phase to phase at the time I couldn't remember how to hook it delta the secondary just had 3 bars for each phase couldn't change it there so i was wondering if I could have got 480 if I would have hooked it delta on the primary






RE: transformer
RE: transformer
Is this correct? :
A 12.47 kV - 480V transformer failed.
You also have a 12.47 kV- 4.160 V service and a transformer that puts out 385 volts when connected in a wye on the primary configuration to an unknown primary voltage source (12,470V, 4160V, 480V?).
You want to know what the voltage would be if you connected it in delta on the same unspecified primary voltage.
Switching the transformer primry connection from wye to delta will raise the output voltage by sqroot 3 = 1.732. (Assume no change on the secodnary wiring.)
1.732 x 385V= 666V. Even dropping 10% on the taps only gives 600V.
If you have any nameplate data on your available trasnformers and a better descriptionof what you are trying to do, we may be able to offer some guidance.
RE: transformer
So your telling me for it to even be possible the most I could have saw was around 310 volts phase to phase on the secondary with the primary connected wye?
RE: transformer
A 4160-480 V transformer is probably connected delta-delta. A wye connection on the 4160 V would be unusual. 4160V phase-phase is 2400 V phase-neutral. 2.4kV used to be a common industrial voltage. A 3-phase transformer with three 2400V-480V windings can be wired delta-delta for 480V delta output with 2400V primary or wye-delta for 480V output on a 4160V primary.
I can't envision how the 380V phase-phase output occurred unless there is a transformer problem.
Switching from wye primary to a delta primary connection will increase the secondary delta phase-phase voltage by a 1.732 factor (Square root of 3).
If you took that same 380V output and were able to rewire the secondary connections in wye, you would get about 600V phase-phase, 380V phase-neutral (great for Canadian industry but not much use to you.)
Sounds like its time for a new transformer.
RE: transformer
Rafiq Bulsara
http://www.srengineersct.com