CITB CITB Electrical and Mechanical Systems 2 — Questions and Answers
Question 1: What type of fire extinguisher should NOT be used on an electrical fire on a construction site?
- CO2 extinguisher
- Dry powder extinguisher
- Water extinguisher (Correct answer)
- Electrical-rated dry chemical
Correct answer: Water extinguisher
Water conducts electricity and must never be used on live electrical fires as it creates a serious electrocution risk.
Question 2: What is the recommended safe approach distance from overhead power lines for construction equipment in the US?
- 1 foot
- 3 feet
- 10 feet (minimum) (Correct answer)
- 25 feet
Correct answer: 10 feet (minimum)
OSHA requires a minimum 10-foot clearance from overhead power lines for equipment up to 50kV, with greater distances for higher voltages.
Question 3: Which system distributes conditioned air throughout a building under construction?
- Potable water system
- HVAC ductwork (Correct answer)
- Drainage stack
- Electrical conduit
Correct answer: HVAC ductwork
HVAC (Heating, Ventilation, and Air Conditioning) ductwork distributes conditioned air for climate control in buildings.
Question 4: What does PAT testing stand for in the context of site tools and equipment?
- Portable Appliance Testing (Correct answer)
- Plant Assessment Testing
- Pressurized Appliance Tracking
- Personal Awareness Training
Correct answer: Portable Appliance Testing
Portable Appliance Testing (PAT) is a formal inspection of electrical appliances to ensure they are safe for use on site.
Question 5: A construction site's temporary power distribution board should be protected by which device to prevent overloads?
- Voltage regulator
- Circuit breakers or fuses (Correct answer)
- Capacitor bank
- Transformer only
Correct answer: Circuit breakers or fuses
Circuit breakers or fuses protect distribution boards by automatically interrupting the circuit when current exceeds safe levels.
Question 6: Which mechanical system on a construction site requires a pressure test before commissioning?
- Electrical conduit
- Plumbing and pipework (Correct answer)
- Scaffold system
- Hoarding panels
Correct answer: Plumbing and pipework
Plumbing and pipework systems must undergo pressure testing to verify they are leak-free and structurally sound before being put into service.
CITB CITB Electrical and Mechanical Systems 2
What type of fire extinguisher should NOT be used on an electrical fire on a construction site?