Motor calculations

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

Dual- element, time delay fuses may be sized up to

175% of the motors full load next standard breaker size

Three phase motor with four stator poles has a synchronous speed of

1800 rpm

If the current drawn by a three phase motor operating at 480 volts is 10.2 ampere what will the current most likely be if the motor is reconnected to run and is operated at 240 volts with all conditions being the same

20.4 amperes the amps double with

15 to 18 motor leads

2400b three phase motor

Non time delay fuses can be sized at

300% find next standard breaker size

The most common number of leads found on a three phase wye round motor is

9

Mscps are designed for use in

A special type of fusible switch combination motor starter

Stator windings can be described as

A structure of copper or aluminum wire coils

A synchronous motor is a type

AC motor

A dual voltage motor, delta connected motor always has nine leads

False it can have 12 leads

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

From damaging overload currents

Time delay delays do not

Provide over current protection

Nec section ______ requires that the ampaxity of branch circuit conductors supply a single continuous duty motor must not be less than 125% of the full load current rating.

Section 430.22(A)

Two or more motors of any rating each with its own overload protection can be connected to one branch circuit if

They have individual short circuit protection devices w

The most common three phase motor configuration are

Wye and delta