Ground-fault protection of equipment is required for which of the following systems?

A. 208Y/120 volt, 3-phase, 4-wire with an 800-ampere main breaker
B. 208Y/120-volt, 3-phase, 4-wire with a 1200-ampere main breaker
C. 480Y/277-volt, 3-phase, 4-wire with an 800-ampere main breaker
D. 480Y/277-volt, 3-phase, 4-wire with a 1200-ampere main breaker


D. 480Y/277-volt, 3-phase, 4-wire with a 1200-ampere main breaker

Trades & Technology

You might also like to view...

To find the total resistance in a series circuit, you would ____ the individual resistances.

A. add B. subtract C. multiply D. take the reciprocal of the sum of

Trades & Technology

Boiler water temperature is typically controlled by a(n) _____

a. aquastat b. thermostat c. limit switch d. bi-metal dis

Trades & Technology

A two-phase power system has two voltages that are _____ out of phase.

A. 60° B. 90° C. 180° D. 360°

Trades & Technology

Oil pressure safety controls measure the difference in pressure between the ____.

A. oil pump inlet and discharge pressures B. oil pump discharge pressure and compressor head pressure C. oil pump inlet pressure and compressor suction pressure D. oil pump discharge pressure and compressor crankcase pressure

Trades & Technology