201174 Electrocution from unsafe plug

Edited from IMCA Safety Flash 02/10

An offshore installation was undergoing major refit works at a repair yard. There were a large number of sub-contractors working at many locations, including fitting a new detachable electrical power supply system to the temporary living quarters (TLQ). However, when it was observed that there was no power supply, the ship’s electrician was asked to investigate. He saw that the main power supply lead cable, terminating at a 4-pin-male plug, was disconnected from the socket/isolator. Without ascertaining that the terminals were not live, he grabbed the plug in an attempt to push it into the female socket and immediately received a 440 Volt electric shock, sustaining an electric burn on the left middle finger and an abrasion on the right palm. He was attended to by medical personnel onboard the vessel and an ECG (electrocardiograph) was recorded. He was admitted to hospital for 24 hours and subsequently placed on light duties for a few days.

Root cause/contributory factors
1. The TLQ’s wiring system was fitted with female sockets which resulted in the extension supply lead cable having live male ends;
2. The 440 Volt power supply was not isolated from the main switchboard prior to the re-connection attempt.

Corrective/preventative actions
1. The sockets on all the three TLQ modules were changed for male sockets so that the live supply wire terminals could be fitted with safer female  plugs;
2. The manufacturer of the TLQ modules was informed of this potentially hazardous arrangement of power supply sockets;
3. The importance of rigorous lock-out tag out procedures was reinforced to crew and fleet.

 

 

Editor’s note: Similar electrical plugs and connectors may be encountered on refrigerated (reefer) containers, portable blowers, pumps, welding  transformers and accessories (extension/jumper cables and ‘pigtails’ etc.). Mariners must exercise great caution before handling such cables and connectors, ensuring that the power has been switched off locally before making or breaking the circuit. In equipment incorporating a capacitor or electrical condenser, (e.g. motor starter), it is possible that residual potential difference or voltage may still exist between the terminals even when the equipment is switched off/circuit is broken/breaker is open.