3B Module 2 HW

A circuit breaker suitable for use as a motor disconnecting means must have a current rating of at least _____.

115% of the motor full-load current

If a squirrel cage induction motor draws 2A of current at 240V and is connected for use on 480V, the amperage will be _____.

1A

Of the following motors, the one most likely to have 15 or 18 motor leads is the _____.

2,400V three-phase motor

If two 10 Ω windings are connected in series for operation on 480V, the total impedance is _____.

20 Ω

The synchronous speed of a 60Hz, three-phase induction motor with two poles is _____.

3,600 RPM

The total resistance of the stator windings in a three-phase motor, if the windings are connected in parallel and the resistance of each winding is 96 Ω, is _____.

48 Ω

With 240V applied to a total parallel impedance of 5 Ω, the current is _____.

48A

If the stator windings of a dual-voltage motor both have an impedance of 10 Ω and they are connected in parallel, the total impedance is _____.

5 Ω

The most common number of motor leads found on a three-phase, wye wound motor is _____.

9

The type of a three-phase motor is determined by the _____.

Rotor

Stator windings can best be described as _____.

a structure of copper or aluminum wire coils

The main purpose of motor overload protection is to protect the motor _____.

from damaging overload currents

Doubling the voltage on a dual-voltage motor _____.

halves the full-load current

The synchronous speed of a motor is the _____.

speed at which the magnetic field rotates

the two most common three-phase motor configurations are _____.

wye and delta