CFESA Electrical and Mechanical Systems 2

Question 1

What is the purpose of a contactor in commercial food equipment?

Accepted Answer

To switch high-current loads on and off via a low-current control circuit

Answer

A contactor uses a small control circuit to open and close contacts that switch heavy loads like compressors and heating elements.

Question 2

A commercial fryer's heating element reads infinite resistance with an ohmmeter. What does this indicate?

Accepted Answer

The element has an open circuit and must be replaced

Answer

Infinite resistance on an ohmmeter indicates an open (broken) circuit within the heating element, meaning current cannot flow.

Question 3

Which type of mechanical seal failure would cause refrigerant oil to appear on the outside of a compressor?

Accepted Answer

Shaft seal leakage

Answer

A leaking shaft seal allows refrigerant oil to migrate along the crankshaft and appear on the compressor exterior.

Question 4

When checking a three-phase motor for balance, what should the amperage readings between the three legs be?

Accepted Answer

Within 10% of each other

Answer

Amperage imbalance greater than 10% between legs indicates a problem with the power supply or the motor windings.

Question 5

What is the function of a pressure differential switch on a commercial ice machine?

Accepted Answer

To detect a dirty condenser or refrigerant restriction and shut the unit down

Answer

A pressure differential switch monitors the difference between high and low side pressures and shuts down the machine if the spread indicates a problem like a dirty condenser.

CFESA - Commercial Food Equipment Service Association Practice Test

CFESA - Commercial Food Equipment Service Association Practice Test

CFESA Electrical and Mechanical Systems 2