said by tschmidt: said by leibold:
Utility companies are well aware that they can far exceed that rating at the expense of a shorter lifespan for the transformer.
Yup - I can attest to that from first hand experience.
When we built our house installed a 200A service plus 30A separately metered service for hot water. Except for kitchen stove appliances are electric. Even space heating is electric to backup wood stove.
We are 600 feet off the road so have our own pole pig. Power company installed a 10 KW transformer. Being the good engineer that I am felt obligated to point out that 200A x 240V is 48 KW. The supervisor smiled knowingly and said that was true but transformer has tremendous overload capacity. If we were able to overload it they would be happy to replace it.
Well that was 30+ years, a direct lightning strike, and two kids ago and the transformer is still going strong. It will probably still be there after I'm in the ground.
That's interesting since my transformer that feeds 4 homes started out at 15 kva, changed to 25 kva, then 50 kva and now 75 kva all without any problems I'm aware of. I'm sure my 300 amp upgrade didn't trigger it since the original drop wire from when the house was 60 amp was installed.