The Southern California Edison Co. has replaced the noisy ground-mounted transformer behind John Davis’ house with a quieter, more expensive model ordered by the commission.

Q This is an old question, but I would appreciate additional input. We have a utility main service, wye-wye pad-mounted transformer, three-phase, four-wire secondary with ground ring and four rods, ...

A. No. The NEC requires the neutral conductor of a transformer that meets the definition of a separately derived system to be connected to the equipment-grounding conductor at the transformer or the ...