Electricity level 3 section 9

If a motor has a current draw of 20A at 240V, what will the amperage be if 480V is applied?

10A

The maximum recommended size of a dual-element, time-delay fuse for a 50hp, 460V, three-phase motor rated at 65 FLA is

125A

If the total resistance of two motor windings connected in parallel is 20ohms and 240V is applied to the circuit, how much current will flow?

12A

What is the maximum value for short circuit protection for multi-motor branch circuits?

250% of the smallest motor

For ordinary motors, the short circuit/ground fault protection for non-time-delay fuses are sized at what percentage of the motor full current?

300%

The requirements for torque motors, shaded-pole motors, permanent split capacitor motors, and AC adjustable-voltage motors can be found in

NEC section 430

Which of the following is true concerning the starting current of an induction motor at the moment the circuit is energized?

The current rises rapidly.

When sizing equipment grounding conductors for branch circuits of continuous duty motors,

combine the rating of each branch circuit OCPD and, when applicable, the rating of each overload protective device

Good electrical protection for a motor includes both proper overload protection and

current-limiting short-circuit protection

In addition to short circuit protection, MSCPs may also serve as a

disconnecting means

One of the three factors that will cause a three-phase motor's magnetic field to rotate is that the

stator windings around the inside of the motor are arranged in a specific manner to induce rotation

If the total resistance of two motor windings connected in parallel is 24ohms and 240V is applied to the circuit, how much current will flow?

10A

If a 480V, three-phase motor control center feeds a 50hp motor (65A), a 40hp motor (52A), and a 10hp motor (14A), the minimum feedee ampacity is

147.25A

The most effective method of power factor correction is the installation of

Capacitors

The synchronous speed of an induction motor is determined by the number of stator poles and the

Frequency in hertz

Which of the following describes MSCPs?

Fuse-like devices designed for use only in a special type of fusible-switch combination motor starter

When used for short circuit protection of motor branch circuits, which of the following must be adjustable and used in conjunction with combination motor starters?

Instantaneous trip circuit breakers

Which of the following lists the full-load currents for three-phase motors with a known winding type, horsepower, and voltage?

NEC Table 430.250

When a motor is oversized, a higher degree of overload protection can be provided by sizing the fuses based on the

full-load current

To calculate the maximum safe load that a motor may be expected to carry continuously at its rated voltage and frequency, the service factor is multiplied by the

horsepower rating