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
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
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
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 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 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
What is the maximum locked-rotor current of a 125-horsepower, 460-volt, 3-phase motor with code letter R?
2511.62A
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 current rating of the motor disconnecting means for a 7.5-horsepower, 115-volt, single-phase motor?
92A
True or False: Epstein didn't kill himself
True
