Electrical Flash Over

Safety Incident Topic : Electrical Flash Over
Location Of Incident : Kuantan, Malaysia
Date Of Incident : 24th July, 2005

Brief Account Of Incident
A lost time injury incident occurred when a contractor worker was exposed to a severe electrical flash-over while servicing the 11KV cable connection bar in a substation during a turnaround.

Outcome
First degree burn due to severe electrical flash-over.

Active Failures
The Active Failure leading to the incident was the 11KV cable connection bar was still energized when the contractor worker applied the earth bonding clamps resulting in a severe electrical flash-over.

Lessons Learned
1. Two separate PTWs were issued for the same activity:
i) servicing of front and back portion of switchboard and
ii) switching for isolation of front portion of the switchboard. A single PTW shall be issued for one activity and the switching for isolation shall be recorded in the Electrical Isolation Certificate.

2. The following shortcomings were observed in permitting processi) PTW – electrical hazard not identified, inadequate precautions & electrical PPEs not specified and contractorworker did not signed andii) Electrical Isolation Certificate – Lock-out and tag-out section not filled, Competent Person signing is not qualifiedBO and inadequate briefing/communication between issuer and receiver. The established PTW procedure shall bestrictly enforced and audited regularly to ensure full compliance.

3. The practice of radio-called a competent person to ask for approval for permit/certificate and then signed by anotherparty shall be stopped.

4. Inadequate communication and coordination between different turnaround teams and contractors during execution of works could result in miscommunication and different understanding of an intent.

5. Established lock-out and tag-out procedure shall be strictly enforced including use of tag, dedicated locks and key box for control of issuance of locks & keys.

6. Correct method of applying earth bonding clamps shall be used.

7. If you are working on an electrical equipment, never assume it is de-energised unless tested and confirmed byyourself.