[BC] 110 V DC

[PeterH5322]

>I was questioning if the voltages that Peter quoted corresponded to our
>120-208 and 277-480 systems

North America is predominately a 120/240 single-phase system, which is 
inherently 240 three-phase delta.

EU (and others) is predominately a 220/230/340 system, which is 
inherently wye.


In North America, you get three wires: 120 volts to ground, neutral, and 
120 volts to ground.

240 is obtained from the two ungrounded conductors.

120 is obtained from either of the two ungrounded conductors to the 
neutral.

Three-phase 240 delta is possible, as is three-phase 480 delta.

Most three-phase, however, is 120/208 wye, or 277/480 wye.

(Almost all transmission is delta, as this requires only three 
conductors, and has no "zero sequence" currents. Wye transmission, which 
requires four conductors, and has "zero sequence" currents, is rare).


In Europe (and elsewhere) there is one ungrounded conductor and one 
grounded conductor.

The ungrounded single-phase conductor could be 220, 230 or 240, 
corresponding to a 380 wye, 400 wye or 415 wye three-phase system.