CITB CITB Electrical and Mechanical Services 2 — Questions and Answers
Question 1: What is the purpose of a lockout/tagout (LOTO) procedure in construction electrical work?
- To secure site gates overnight
- To prevent accidental energization of equipment during maintenance (Correct answer)
- To label electrical panels for inspection
- To record power outages
Correct answer: To prevent accidental energization of equipment during maintenance
LOTO procedures ensure energy sources are isolated and cannot be re-energized while workers perform maintenance.
Question 2: What British thermal unit (BTU) rating indicates the heating or cooling capacity of HVAC equipment?
- Watts
- Amperes
- BTU/hr (Correct answer)
- Pascals
Correct answer: BTU/hr
BTU per hour (BTU/hr) is the standard US measurement of heating or cooling output for HVAC equipment.
Question 3: Which type of electrical conduit provides the best mechanical protection in exposed construction areas?
- PVC conduit
- Flexible metal conduit (FMC)
- Rigid metal conduit (RMC) (Correct answer)
- Electrical metallic tubing (EMT)
Correct answer: Rigid metal conduit (RMC)
Rigid metal conduit (RMC) offers the highest mechanical protection and is used in areas subject to physical damage.
Question 4: What is the minimum ampacity required for a 20-amp branch circuit conductor under NEC rules?
- 15 amps
- 20 amps (Correct answer)
- 25 amps
- 30 amps
Correct answer: 20 amps
Conductors for a 20-amp branch circuit must be rated at least 20 amps under NEC Article 210.
Question 5: In plumbing, what is the function of a P-trap?
- To filter sediment from water supply
- To hold a water seal preventing sewer gas entry (Correct answer)
- To regulate water pressure
- To connect copper to PVC pipe
Correct answer: To hold a water seal preventing sewer gas entry
A P-trap maintains a water seal in the drain line that blocks sewer gases from entering the building.
Question 6: Which test is performed on a new plumbing rough-in before walls are closed to verify no leaks exist?
- Pressure test (Correct answer)
- Smoke test
- Flow test
- Both pressure and air tests
Correct answer: Pressure test
A hydrostatic (water) pressure test pressurizes the system to check for leaks before walls are enclosed.
CITB CITB Electrical and Mechanical Services 2
What is the purpose of a lockout/tagout (LOTO) procedure in construction electrical work?