Site Safe Electrical Safety on Construction Sites 2 — Questions and Answers
Question 1: What must you check on a portable power tool before using it on a NZ construction site?
- That it has a current in-date test and tag (Correct answer)
- That it is a recent model from a reputable brand
- That it was purchased locally within NZ
- That its colour matches site equipment standards
Correct answer: That it has a current in-date test and tag
Before using any portable electrical equipment on site, you must verify it has a current (in-date) test and tag confirming it has been inspected and is safe.
Question 2: What action should you take if a portable power tool has a damaged or frayed power cord?
- Repair the cord with electrical tape and continue use
- Remove the tool from service and tag it as faulty (Correct answer)
- Only use the tool while wearing rubber-soled boots
- Ask a colleague to hold the cord away from wet areas
Correct answer: Remove the tool from service and tag it as faulty
Any electrical equipment with damaged insulation must be immediately removed from service and tagged as faulty until repaired by a qualified person.
Question 3: What does the 'lock out, tag out' (LOTO) procedure achieve in electrical safety?
- It locks storage areas containing electrical equipment
- It ensures equipment is isolated and cannot be accidentally energised during maintenance (Correct answer)
- It tags cables to identify their purpose and voltage
- It locks electrical panels from access by unauthorised personnel
Correct answer: It ensures equipment is isolated and cannot be accidentally energised during maintenance
Lock out, tag out is a safety procedure that isolates and de-energises electrical equipment so it cannot be accidentally restarted while a worker is performing maintenance.
Question 4: In NZ, what voltage threshold defines 'extra low voltage' (ELV)?
- Below 50V AC or 120V DC (Correct answer)
- Below 240V AC
- Below 110V AC
- Below 400V AC
Correct answer: Below 50V AC or 120V DC
Extra low voltage (ELV) in NZ is defined as not exceeding 50V AC or 120V DC under the Electricity (Safety) Regulations 2010.
Question 5: When working in wet conditions on a construction site, what additional electrical precaution is required?
- Use longer extension leads to distance yourself from water
- Ensure all electrical equipment is double insulated or protected by an RCD (Correct answer)
- Work more quickly to reduce your time in wet conditions
- Only battery-operated tools may be used during rainfall
Correct answer: Ensure all electrical equipment is double insulated or protected by an RCD
Wet conditions greatly increase electric shock risk, so all equipment must be double insulated or RCD-protected when working in wet environments.
Question 6: Which of the following is NOT a warning sign of an electrical hazard on a construction site?
- A tingling sensation when touching equipment
- A burning smell from an electrical panel
- Equipment that repeatedly trips the RCD
- A power tool with a current green test tag (Correct answer)
Correct answer: A power tool with a current green test tag
A current green test tag indicates the equipment has been inspected and passed safety testing, making it a sign of safety rather than a hazard.
Question 7: What is the correct response when an RCD trips on a construction site?
- Reset it immediately and continue working
- Reset it once; if it trips again, investigate the fault before using the circuit (Correct answer)
- Bypass the RCD using an extension lead from another circuit
- Remove the RCD as it may be faulty and replace with a standard plug
Correct answer: Reset it once; if it trips again, investigate the fault before using the circuit
If an RCD trips, you may reset it once, but if it trips again this indicates a fault that must be investigated by a qualified person before the circuit is used again.
Site Safe Electrical Safety on Construction Sites 2
What must you check on a portable power tool before using it on a NZ construction site?