CITB Electrical and Mechanical Systems Flashcards
6 cards from real CITB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CITB Electrical and Mechanical Systems flashcards as text
What is the primary hazard when working near buried electrical cables during excavation?
Answer: Electrocution and arc flash
Striking a buried live cable during excavation can cause electrocution or an arc flash, which are potentially fatal hazards.
Before excavating, what document should a contractor obtain to identify underground utilities?
Answer: Underground utility survey or 'as-built' drawings
An underground utility survey or 'as-built' drawings identify the location of buried services to prevent accidental strikes during excavation.
What is the function of a step-down transformer commonly used on US construction sites?
Answer: Reduces voltage to safer working levels (e.g., 110V)
A step-down transformer reduces mains voltage to a safer level, typically 110V center-tapped, reducing the risk of fatal electric shock on site.
Who must sign off on a hot works permit before welding or cutting begins on a construction site?
Answer: An authorized supervisor or safety officer
An authorized supervisor or safety officer must sign the hot works permit, confirming fire prevention measures are in place before work begins.
Which regulation governs the safe use of electricity at work in construction in the United States?
Answer: OSHA 29 CFR 1926 Subpart K
OSHA 29 CFR 1926 Subpart K — Electrical — governs electrical safety standards for construction workers in the United States.
What action should a worker take if they discover a damaged electrical cable on a construction site?
Answer: Isolate the circuit and report to a supervisor immediately
A damaged cable must be immediately reported and the circuit isolated to prevent electrocution until a competent electrician makes a proper repair.