What voltage do the DC generators in locomotives present an electrical hazard during derailments?

What voltage do the DC generators in locomotives present an electrical hazard during derailments?

• A. 120 volt DC
• B. 220 volt AC
• C. 440 volt DC
• D. 12 volt DC

Answer: (C)

High-voltage DC traction power is what drives a locomotive’s motors, and in derailments this system can be a live electrical hazard. The nominal traction voltage around 440 volts DC is high enough to cause lethal shock, and DC current tends to create a sustained muscular contraction that can make it difficult to release a conductor if contact is made. The risk remains even after the locomotive is shut down, because the electrical network can still be energized or re-energized by motion or other connected equipment, and energy can be stored in capacitors and bus bars. Therefore, any exposed conductors should be treated as energized until properly isolated by qualified personnel. The other options don’t fit because they describe the wrong type (AC) or voltages that are far too low for main locomotive traction power.

High-voltage DC traction power is what drives a locomotive’s motors, and in derailments this system can be a live electrical hazard. The nominal traction voltage around 440 volts DC is high enough to cause lethal shock, and DC current tends to create a sustained muscular contraction that can make it difficult to release a conductor if contact is made. The risk remains even after the locomotive is shut down, because the electrical network can still be energized or re-energized by motion or other connected equipment, and energy can be stored in capacitors and bus bars. Therefore, any exposed conductors should be treated as energized until properly isolated by qualified personnel. The other options don’t fit because they describe the wrong type (AC) or voltages that are far too low for main locomotive traction power.