Article 430 - Motors, Motor Circuits, and Controllers (QUARTER 2)

Each motor used in a continuous duty application and rated more than 1 hp shall be protected against overload by a separate overload device that is responsive to motor current. The overload device for motors with a marked temperature rise 40°C or less, shall be rated at no more than _____ percent of the motor nameplate full-load current rating.

125

Branch-circuit conductors supplying a single continuous-duty motor shall have an ampacity not less than _____ rating.

125 percent of the motor\'s full-load current rating as determined by 430.6(A)(1)

The maximum dual-element time-delay fuse branch circuit protection for a single-phase motor is _____ percent of the appropriate current rating found in Table 430.248.

175

The maximum rating or setting of an inverse time breaker used as the motor branch-circuit short-circuit and ground-fault protective device for a single-phase motor is _____ percent of the full-load current given in Table 430.248.

250

Article _____ covers motors, motor branch-circuit and feeder conductors and their protection, motor overload protection, motor control circuits, motor controllers, and motor control centers.

430

For stationary motors of 2 hp or less and 300V or less on ac circuits, the controller can be an ac-rated only general-use snap switch where the motor full-load current rating is not more than _____ percent of the rating of the switch.

80

The maximum instantaneous trip breaker branch circuit protection for a single-phase motor is _____ percent of the appropriate current rating found in Table 430.52.

800

For general motor applications, the motor branch-circuit short-circuit and ground-fault protection device shall be sized based on the _____ values.

NEC Table

A horsepower-rated _____ having a horsepower rating not less than the motor rating shall be permitted to serve as the disconnecting means.

attachment plug and receptacle or flanged surface inlet and cord connector

A _____ rated in amperes shall be permitted as a controller for all motors.

branch-circuit inverse time circuit breaker or molded case switch

A _____ shall be located in sight from the motor location and the driven machinery location.

disconnecting means

Overload devices are intended to protect motors, motor control apparatus, and motor branch-circuit conductors against _____.

excessive heating due to motor overloads and excessive heating due to failure to start

Conductors supplying several motors, or a motor(s) and other load(s), shall have an ampacity not less than the sum of 125 percent of the full-load current rating of the highest rated motor plus the sum of the full-load current ratings of all the other motors in the group and 100 percent of the remaining noncontinuous and continuous nonmotor loads.

false

In determining the highest rated motor for purposes of complying with 430.24, 430.53(B), and 430.53(C), the highest rated motor shall be based on the rated full-load current as selected _____.

from Tables 430.247, 430.248, 430.249, and 430.250

If a motor disconnecting means is a motor-circuit switch, it shall be rated in _____.

horsepower

A motor disconnecting means can be a listed _____.

molded case circuit breaker, motor-circuit switch rated in horsepower, molded case switch ( any of these)

Motors shall be located so that adequate _____ is provided and so that maintenance, such as lubrication of bearings and replacing of brushes, can be readily accomplished.

space

A branch-circuit overcurrent device can serve as the disconnecting means for a stationary motor of 1/8 hp or less.

true

Circuit conductors on the output of an adjustable-speed drive system are susceptible to breakdown under certain conditions due to the characteristics of the output waveform of the drive.

true

Motor control circuits shall be arranged so they will be disconnected from all sources of supply when the disconnecting means is in the open position.

true

Where more than one motor disconnecting means is provided in the same motor branch circuit, at least one of the disconnecting means shall be readily accessible.

true

Circuit conductors on the output of an adjustable-speed drive system are susceptible to breakdown under certain conditions. Factors affecting the conductors include but are not limited to the output _____.

voltage, frequency, or current (any of these)

Conductors supplying several motors shall not be sized smaller than _____ percent of the full-load current rating of the highest rated motor, plus the sum of the full-load current ratings of all other motors in the group, plus the ampacity of other loads.

125%

Motor control circuit conductors that extend beyond the motor control equipment enclosure shall have short-circuit and ground-fault protection sized not greater than _____ percent of the value specified in Table 310.16 for 60°C conductors.

300

Overcurrent protection for motor control circuits shall not exceed _____ percent if the conductor is based on Table 310.17 and does not extend beyond the motor control equipment enclosure.

400

An individual disconnecting means shall be provided for each motor controller and be located _____ from the controller location.

in sight

Part IV of Article 430 specifies devices intended to protect _____ against overcurrent due to short circuits or ground faults.

motor branch-circuit conductors, motor control apparatus, motors ( all of these)

A feeder supplying fixed motor load(s) shall have a protective device with a rating or setting _____ branch-circuit short-circuit and ground-fault protective device for any motor in the group, plus the sum of the full-load currents of the other motors of the group.

not greater than the largest rating or setting of the

The motor controller shall have horsepower ratings at the application voltage _____ the horsepower rating of the motor.

not lower than

A motor can be provided with combined overcurrent protection using a single protective device to provide branch-circuit _____ protection where the rating of the device provides the overload protection specified in 430.32.

short-circuit, ground-fault, motor overload ( all of these)

Where the motor short-circuit and ground-fault protection devices determined by Table 430.52 do not correspond to the standard sizes or ratings, a higher rating that does not exceed the next higher standard ampere rating shall be permitted.

true

Motors shall be located so that adequate _____ is provided and so that maintenance, such as lubrication of bearings and replacing of brushes, can be readily accomplished.

ventilation