American Voltage

[Sanditech]

Hi
I am trying to find the common voltage level(LV)of medium to large industrial plants in North America. All I can ascertain at present is a domestic level of 120V 60Hz P-N.
Which based on the standard UK distribution sytem would give 210V P-P ?
But do industrial (petro-chem) use this as there main LV distribution voltage level?

SANDITECH

 

[UKpete]

For domestic supplies worldwide:

http://kropla.com/electric2.htm

In terms of population, 50Hz wins (ok, China helps).

davidbeach - interesting theory, it is the two WWs after all that started the whole European Union thing.
Incidentally, everyone in Europe gets on fine now! except when we play football (that's soccer) and a few other occasions.

 

[mc5w]

We also have 240 volts corner grounded 3-wire 3-phase power and a smaller amount of 480 volts corner grounded.

We also have resistance grounded 3-wire 3-phase power in a few instances where reliability is important and a limited source of ground fault current is needed for tracing and disconnecting ground faults in a timely matter.The voltage levels in these cases are usually 480 volts, 600 volts, 1,040 volts, and 4,160 volts. The supply transformers would be 277Y480, 437Y600, 600Y1,040, and 2,400Y4,160 volts.

There are also a few places that do have oddball voltages or 25 Hertz power. Here is Cleveland the steel mills make their own 25 Hertz power for big motors using cycloconverters. When machine speed goes down and machine torque goes up the optimal frequency drops down to about 15 to 30 Hertz. In actuality, the cycloconverters for each motor are adjustanble in frequency both for starting purposes and to tweak the speed.

In 1 place where I worked some 40 Horsepower 10 pole 60 Hertz motors had been replaced with 4-pole 100 Horsepower or 125 Horsepower inverter duty motors. They then used variable frequency drives to feed 24 Hertz power into the motors. Thanks to VFDs you can generate any custom frequency you would want.