Billy_Bob
In the Trades
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Why is a ground wire required from a generator to a building's main electric panel, yet no ground wire is provided from the electric company's transformer?
Why does the electric company not provide a ground wire either with a pole mounted transformer or a pad mounted transformer on the ground? (I was thinking that the electric company reason was that their transformers are up high in the air and no one can touch these (except qualified persons). But then there is the case of pad mount transformers which are on the ground...
I see with the following that pad mount transformers are grounded using a special method...
"Provide a 1/0 bare copper-ground girdle around transformer. Girdle shall
be buried 305 mm one foot deep and placed 915 mm 3 feet laterally from the
transformer enclosure. Connect girdle to enclosure at two opposite places
using 1/0 copper. Exothermically weld joints."
http://www.wbdg.org/ccb/DOD/UFGS/UFGS 26 12 19.20.pdf
Picture...
Then another difference would be the wiring from a generator to a building. The wiring from a generator would tend to be temporary - perhaps strung on the ground. The electric company's wiring would be high in the air or far underground in well protected conduit.
Then people would tend to have their hands all over a generator, especially if there is an electrical problem. For the electric company transformer, only qualified persons would work on these.
And is the neutral bonded to ground at a pad mounted transformer? Or is just the case grounded?
Why does the electric company not provide a ground wire either with a pole mounted transformer or a pad mounted transformer on the ground? (I was thinking that the electric company reason was that their transformers are up high in the air and no one can touch these (except qualified persons). But then there is the case of pad mount transformers which are on the ground...
I see with the following that pad mount transformers are grounded using a special method...
"Provide a 1/0 bare copper-ground girdle around transformer. Girdle shall
be buried 305 mm one foot deep and placed 915 mm 3 feet laterally from the
transformer enclosure. Connect girdle to enclosure at two opposite places
using 1/0 copper. Exothermically weld joints."
http://www.wbdg.org/ccb/DOD/UFGS/UFGS 26 12 19.20.pdf
Picture...
Then another difference would be the wiring from a generator to a building. The wiring from a generator would tend to be temporary - perhaps strung on the ground. The electric company's wiring would be high in the air or far underground in well protected conduit.
Then people would tend to have their hands all over a generator, especially if there is an electrical problem. For the electric company transformer, only qualified persons would work on these.
And is the neutral bonded to ground at a pad mounted transformer? Or is just the case grounded?