M mrlee Member Oct 10, 2007 #1 A building supplied with a 400-amp, 3-phase, 208Y/120V, 4-wire service with a underground conductor size of 500KC copper. The maximum calculated unbalanced load for the building is 20amps. What size copper neautral is required for the service.
A building supplied with a 400-amp, 3-phase, 208Y/120V, 4-wire service with a underground conductor size of 500KC copper. The maximum calculated unbalanced load for the building is 20amps. What size copper neautral is required for the service.
roger Moderator Staff member Location Fl Occupation Retired Electrician Oct 10, 2007 #2 See 220.61 Roger
radiopet Senior Member Location Spotsylvania, VA Oct 10, 2007 #3 And then don't forget to check 250.24(C)(1) as well....
