Protecting conductors For a 1,200-ampere (A), three-phase, 120/208-volt (V) service, can I run three sets of 500 kcmil underground from the transformer pad to the main 1,200A switch, or does it have to be 600 kcmil?
Article 240 in the National Electrical Code (NEC) provides general requirements for overcurrent protection and overcurrent protective devices.





