WALMART MAINTENANCE Building Systems 3

Question 1

What is the purpose of an expansion tank in a closed-loop hydronic heating system?

Accepted Answer

Absorb pressure increases as water expands when heated

Answer

An expansion tank accommodates the increased volume of water as it heats up, preventing dangerous pressure spikes in a closed system.

Question 2

Which lighting control system automatically dims or turns off lights based on occupancy?

Accepted Answer

Occupancy sensor

Answer

Occupancy sensors detect motion or body heat to automatically control lighting, reducing energy waste in unoccupied spaces.

Question 3

What is the recommended minimum slope for a commercial flat roof to ensure proper drainage?

Accepted Answer

1/4 inch per foot

Answer

A minimum slope of 1/4 inch per foot (2%) is the standard requirement for flat roofs to prevent ponding water.

Question 4

In electrical systems, what does 'grounding' a circuit primarily protect against?

Accepted Answer

Electric shock and equipment damage from fault currents

Answer

Grounding provides a safe path for fault current to flow, tripping the breaker and protecting people and equipment from dangerous voltages.

Question 5

A building's exhaust fan is making excessive noise. Which component is most likely the cause?

Accepted Answer

Worn or loose bearings

Answer

Worn or loose bearings are the most common cause of excessive fan noise and require lubrication or bearing replacement.

WALMART MAINTENANCE Practice Test