Services, Grounding & BondingPregunta 55 de 120
Ground-fault protection of equipment is required for a solidly grounded wye service with more than 150 volts to ground when the disconnect is rated at least what value?
a.800 amperes
b.1,000 amperes
c.600 amperes
d.1,200 amperes
Explicación
The threshold is a service disconnect rated 1,000 amperes or more on a solidly grounded wye system of more than 150 volts to ground but not exceeding 1,000 volts phase-to-phase, which describes a typical 480Y/277-volt service. The 1,200-ampere figure is the maximum permitted setting of the ground-fault protection, not the threshold at which it is required.
Referencia Legal: 2023 NEC §230.95Practica las 120 preguntas gratis — sin registro.
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