Working Near Electrified Lines Flashcards

A worker needs to cross over a live electrified third rail. What is the correct method?

Answer: Use an approved insulated crossing board placed over the rail

An approved insulated crossing board must be placed over the third rail to provide a safe, non-conductive path across it.

What is the purpose of a 'short circuit device' applied to an isolated section of electrified track?

Answer: To provide a visible and functional earth that protects against accidental re-energization

A short circuit device provides both a visible indicator and a functional earth connection, ensuring that any accidental re-energization trips protection systems immediately.

At what voltage does the US National Electrical Safety Code classify overhead transmission lines as 'high voltage' requiring strict clearance protocols?

Answer: Above 600V

NESC generally classifies lines above 600V as high voltage, requiring strict minimum approach distances and additional safety protocols.

Which of the following is NOT a valid method for confirming electrical isolation before beginning work?

Answer: Assuming isolation because no train is scheduled for the next hour

Assuming isolation based on train schedules is never acceptable — formal confirmation through authorized channels and physical verification is always required.

Why must workers avoid touching two conductive objects simultaneously when working near electrified infrastructure?

Answer: A worker can become part of a circuit if the objects are at different potentials, causing electrocution

Simultaneously touching two objects at different electrical potentials completes a circuit through the worker's body, allowing potentially fatal current to flow.

What action is required before using any electrical test equipment near a live electrified line?

Answer: Verify the equipment is rated for the voltage present and has a current calibration certificate

Electrical test equipment must be rated for the voltage level present and must have a valid calibration certificate to ensure accurate and safe readings.

During a PTS briefing, a supervisor states that the adjacent line remains live while work proceeds on the isolated line. What must all workers do?

Answer: Maintain required clearance from the live adjacent line and avoid any equipment encroachment

Workers must maintain required approach distances from any adjacent live line at all times, ensuring no person or equipment encroaches on the live line's danger zone.