PTS Working Near Electrified Lines 2 — Questions and Answers
Question 1: What is the term used for the voltage that can pass through the ground from a downed electrified rail or wire, creating a hazard over a wide area?
- Ground potential rise
- Step potential (Correct answer)
- Touch voltage
- Induction voltage
Correct answer: Step potential
Step potential is the voltage difference between two points on the ground surface, which can cause current to flow through a person's legs.
Question 2: When working near a 750V DC electrified third rail, what is the minimum approach distance a worker must maintain without protective equipment?
- 6 inches
- 12 inches (Correct answer)
- 18 inches
- 24 inches
Correct answer: 12 inches
A minimum approach distance of 12 inches is generally required from a 750V DC third rail without special protective equipment.
Question 3: Which condition makes working near electrified lines MORE dangerous than usual?
- Dry weather
- Cold temperatures below freezing
- Wet or humid conditions (Correct answer)
- High winds with no rain
Correct answer: Wet or humid conditions
Wet or humid conditions lower the resistance of materials and the human body, increasing the risk of electrical shock.
Question 4: A train is approaching while a worker is within the electrified zone. What is the FIRST priority?
- Signal the train to stop
- Move to a place of safety immediately (Correct answer)
- Secure all tools and equipment
- Notify the supervisor
Correct answer: Move to a place of safety immediately
Personal safety is always the first priority — the worker must immediately move to a designated place of safety before the train arrives.
Question 5: What does 'bonding' a section of track mean in the context of electrified railway work?
- Connecting rails to increase signal strength
- Electrically connecting components to equalize potential and reduce shock risk (Correct answer)
- Attaching warning signs to the track
- Securing rail joints with adhesive compounds
Correct answer: Electrically connecting components to equalize potential and reduce shock risk
Bonding equalizes electrical potential between conductive components, reducing the risk of dangerous voltage differences during work.
Question 6: Who is responsible for issuing a 'Line Blockage' or electrical isolation before track workers enter an electrified work zone?
- The most senior track worker on site
- Any certified first aider
- An authorized controller or electrical supervisor (Correct answer)
- The train driver of the next scheduled train
Correct answer: An authorized controller or electrical supervisor
Only an authorized controller or electrical supervisor has the authority to issue a line blockage or confirm electrical isolation.
Question 7: What is 'induced voltage' and why is it a hazard near electrified lines?
- Voltage stored in capacitors within signal boxes
- Voltage generated in conductors near high-current lines without direct contact (Correct answer)
- Voltage created by static discharge from passing trains
- Voltage from underground power cables beneath the track bed
Correct answer: Voltage generated in conductors near high-current lines without direct contact
Induced voltage is created electromagnetically in nearby conductors (like long tools or equipment) due to proximity to high-current electrified lines, posing a shock risk even without direct contact.
PTS Working Near Electrified Lines 2
What is the term used for the voltage that can pass through the ground from a downed electrified rail or wire, creating a hazard over a wide area?