DIYbanter - View Single Post - Converting Compressor motor from 220 v to 110 v

Dean Hoffman[_12_]

On 3/3/17 4:28 PM, wrote:

There is no "phase issue" at all. There is no such thing as "two
phase" power, at least not in common North American use. All 120
volt power in north american distribution systems is derived from
center tapped 240 volt single phase transformers except in a 3 phase
distribution system, where you get 120 and 208 (120 across 1 phase,
and 208 across 2 phases of the 3 phase supply).

The REAs in rural Nebraska also supply three phase power to
irrigation well motors. I've seen center tap delta which is basically
double what you referenced. There is the Y configuration, 277 volts
each line to ground. Lastly is the corner ground delta. Two lines read
480 to
ground, the third line reads 0 to ground. All of those read 480 line
to line.
Some grain bin drying systems are wired with the three phase you
mentioned.
That lets the electricians use common 120 volt controls. There is also
enough
power with the three phase to run drying fans.