Motors 2 Level 9
What is the minimum horsepower motor-circuit switch rating for a 40-horsepower, 460-volt, 3-phase motor marked with a code letter F using the maximum locked-rotor rating?
40HP
What is the minimum current rating of the motor disconnecting means for a 40-horsepower, 208-volt, 3-phase squirrel-cage motor?
131A
What is the minimum horsepower rating for a motor disconnecting means for a 50-horsepower, 440-volt, 3-phase motor marked with a code letter S using the maximum locked-rotor rating?
200HP
Calculate the minimum horsepower rating of the switch from the previous question.
20HP
What is the maximum locked-rotor current of a 125-horsepower, 460-volt, 3-phase motor with code letter R?
2511.62A
A motor disconnect switch is to be installed for a 40-horsepower, 3-phase, 460-volt, Design C motor with a code letter L. Calculate the minimum ampacity for the disconnect switch.
59.8A
What is the minimum current rating of a motor disconnecting means for a 50-horsepower, 3-phase, 440-volt, synchronous motor?
59.8A
A circuit breaker is listed for use as a disconnecting means because it is tested for an interrupting rating of ? times the current rating of the breaker.
6
What is the minimum horsepower rating for a motor disconnecting means for a 50-horsepower, 440-volt, 3-phase motor marked with a code letter F using the maximum locked-rotor rating?
60HP
Calculate the minimum horsepower rating of the motor disconnect switch from the previous question.
7.5HP
What is the minimum horsepower rating of the motor circuit switch for a single-phase, 240-volt 5-horsepower motor marked with code letter M using maximum locked-rotor kVA (kilovolt-ampere)?
7.5HP
True or False: Epstein didn't kill himself
True
A 12-kilowatt, 240-volt, single-phase heater and a 5-horsepower, 240-volt, single-phase motor are to be controlled by the same motor circuit switch. The motors can be started simultaneously.
89.7A
What is the minimum horsepower rating of the motor circuit switch for a 3-phase, 240-volt, 5-horsepower motors marked with code letter M using maximum locked-rotor kVA (kilovolt-ampere)?
10HP
What is the maximum locked-rotor current for a 15-horsepower, 208-volt, 3-phase motor with code letter D?
187.17
One 5-horsepower motor and one 10-horsepower motor, both continuous-duty, 460-volt, 3-phase, are to be installed on the same 480-volt motor circuit. The motors can be started simultaneously.
24.84A
What is the average locked-rotor current for a 20-horsepower, 240-volt, single-phase motor with code letter H?
557.9A
What is the minimum horsepower rating of the motor circuit switch for a 3-horsepower, 115-volt, single-phase motor marked with code letter G using maximum locked-rotor kilovolt-ampere?
3HP
What is the minimum horsepower rating for a motor disconnecting means for a 50-horsepower, 440-volt, 3-phase motor marked with a code letter B using the maximum locked-rotor rating?
40HP
A 40-horsepower, 3-phase, 60-hertz, 460-volt motor is installed with a motor nameplate full-load current rating of 60 amperes, a temperature rise of 40°C, the locked rotor code letter F, and a service factor of 1.15. The motor is a continuous-duty squirrel-cage motor and starting current is not a problem. Calculate the maximum branch-circuit short-circuit and ground-fault protection using time-delay fuses for this motor. Calculate the maximum overload relay protection for this 40-horsepower, 460-volt, 3-phase motor. Calculate the minimum current rating of the motor disconnect switch controlling this motor.
65A 100A 75A 59.8A
A motor switch is to be installed for a 40-horsepower, 3-phase, 460-volt, Design C motor with code letter L. Calculate the minimum horsepower rating of the switch using the maximum locked rotor kVA (kilovolt-ampere).
75HP
What is the minimum standard size inverse-time circuit breaker that can be used as a disconnecting means for a 25-horsepower, 240-volt, 3-phase motor?
80A
What is the minimum current rating of the motor disconnecting means for a 7.5-horsepower, 115-volt, single-phase motor?
92A
