Monday, August 5, 2013

SHORT CIRCUIT IN DB PANEL


INCIDENT DETAILS:

A contractor working at the site installed a new temporary supply from an "Existing DB Panel" to provide power to their temporary site office. As shown in the above photo, the electrician positioned the new cable directly behind the bottom left hand side screw fixing point for DB cover. By the time the work has been completed he closed the panel and everything went fine.
Two working days after, another MEP contractor has been deployed to site to solve some lighting issues. Their electrician opened the existing DB Panel, troubleshoots and make some wiring modifications without requesting first a Permit To Work prior commencing his activity. When the electrician finishes his work, he placed the cover back on the DB Panel and began to insert the screws. When inserting the bottom left hand screw (which was incorrect type of screw), it get contact with the cable (which is live , 240V supply), damage its insulation and causing a short circuit and loss of power. So far, the electrician was okay and no injuries reported.



ROOT CAUSE:
  1. No Permit To Work (PTW) was followed.
  2. Location of the new cable is wrong and poor choice.
  3. The electrician uses incorrect type of screw to fix the DB cover.
  4. No inspection and approval has been made after completion of work prior switching the power supply back to live.
  5. Supervision and quality of work was poor.
 RECOMMENDATIONS:
  • Upon completion of work, a qualified Electrical Engineer should inspect the work for approval.
  • All contractors will carry out Tool Box Talks in relation to this incident immediately to all employees.
  • The cables should not be positioned where there's a possibility to get in contact with screws or sharp objects that can damage the cables.
  • Only correct type of screws MUST be used.
  • All contractors must inspect any item of equipment they intend to work on prior starting their work and inform the main contractor if there are any issues.
  • Workers should always be aware of the hazards involved in modifying items of equipment.
  • A task specific risk assessment and safe method must be followed at all times.
  • Regardless of the length of task a Permit To Work must be requested always for any electrical works.
  • All panels must be electrically isolated and remain isolated until the work is completed.
  • All work must be supervised by a competent person.



No comments:

Post a Comment