CEI CEI Motor & Motor Control Inspection

Question 1

According to NEC Article 430, what is the minimum branch-circuit conductor ampacity for a single motor?

Accepted Answer

125% of the motor full-load current

Answer

100% of the motor full-load current

Answer

150% of the motor full-load current

Answer

80% of the motor full-load current

Question 2

What device is required by NEC Article 430 to protect a motor from overheating under running conditions?

Accepted Answer

Overload protection device

Answer

Branch-circuit fuse

Answer

Ground-fault circuit interrupter

Answer

Short-circuit breaker

Question 3

Which NEC article governs the installation of motors and motor controllers?

Accepted Answer

Article 430

Answer

Article 410

Answer

Article 422

Answer

Article 440

Question 4

When inspecting a motor disconnecting means, what is the minimum horsepower rating requirement for motors rated over 2 hp at 600V or less?

Accepted Answer

The disconnect must be rated at least equal to the motor's hp

Answer

The disconnect must be rated at 115% of the motor's hp

Answer

The disconnect must be rated at 125% of the motor's hp

Answer

The disconnect must be rated at 150% of the motor's hp

Question 5

What is the maximum distance allowed between a motor disconnect and the motor controller, according to NEC 430.102?

Accepted Answer

Within sight from the controller

Answer

Within sight and within 50 feet

Answer

Within sight from the motor

Answer

No distance limit is specified

Question 6

During an inspection of a motor installation, you find the overload relay set at 140% of the motor's full-load current. This is most likely acceptable for which type of motor?

Accepted Answer

A motor with a service factor of 1.15 or greater

Answer

A standard Design B motor

Answer

A wound-rotor motor

Answer

A permanent split-capacitor motor