CPM CPM - Certified Plant Mechanic Electrical Systems and Controls

Question 1

What does NEC stand for in the context of US industrial electrical work?

Accepted Answer

National Electrical Code

Answer

NEC stands for National Electrical Code, the standard for safe installation of electrical wiring and equipment in the US.

Question 2

Which wire color designates a ground conductor in standard US wiring?

Accepted Answer

Green or bare copper

Answer

Green or bare copper wire designates the equipment grounding conductor per NEC standards.

Question 3

What device protects a motor from damage caused by sustained overload currents?

Accepted Answer

Overload relay

Answer

An overload relay monitors motor current and trips the starter circuit when current exceeds the setpoint for a defined time.

Question 4

What is the primary purpose of a GFCI outlet in an industrial plant environment?

Accepted Answer

Protect against ground fault electric shock

Answer

A GFCI (Ground Fault Circuit Interrupter) trips within milliseconds when it detects a difference between hot and neutral current, protecting personnel from shock.

Question 5

What condition results when a 3-phase motor loses one of its supply phases while running?

Accepted Answer

Single phasing occurs causing overheating

Answer

Single phasing causes the motor to draw excessive current on the remaining phases, leading to overheating and potential winding damage.

CPM - Certified Plant Mechanic Practice Test

CPM - Certified Plant Mechanic Practice Test

CPM CPM - Certified Plant Mechanic Electrical Systems and Controls