EGT Safety Alert 75: Electric shock - failure to test the tester

Safety Alert 
75: Electric shock - failure to test the tester

Date
6 June 2018

Description 
An EGT apprentice received an electric shock, burns to his left hand, injuries to both of his elbows and narrowly missed sustaining head injuries as a result of not following robust testing procedures. This incident had all the factors that on another occasion might have resulted in a more serious injury or worse.

The job was a large addition to an old residence in the western suburbs. The clients were still occupying a part of the building during the construction phase. The host employer was doing the rough in installation at the time of incident.

The apprentice was asked by the tradesman to check with the client and then isolate the power and lighting circuits at the switchboard. Other circuits like the steamer oven and the retic pump remained energised. The task was to re-direct some cables around a void, at ceiling height, where a new staircase was to be installed. The ladder was placed in the void between the brick wall of the existing house and a new wall of just wooden studs.

The apprentice did not have his voltstick with him and so he borrowed a voltstick from his tradesman. He climbed the 8 foot fibreglass ladder, opened the junction box, tested for voltage and grabbed the cables with his left hand. He proceeded to disconnect the active conductors when he felt a severe pain in his left arm and found he had no control of his muscles. He could not let go of the cables.

He was trapped for several seconds above the void and it seemed the only apparent option available to him was to deliberately allow himself to fall backwards off the ladder. Fortunately his head missed the wall studs. His elbows and right hip took the brunt of the fall. When he was helped up he discovered burn marks to his left hand.

Root cause

  • The whole installation was not isolated by the main switch.
  • A volt stick was used to confirm the isolation instead of a multimeter (or similar).
  • Identify, Isolate and Test the circuit before Touching (IITT) procedure was not followed.
  • The volt stick was not tested before and after the circuit test to prove the tester was providing a true reading.

Recommendations

  • Host employers must ensure that electrical apprentices are involved in isolation procedures at the switchboard in accordance with Electrical (Licensing) Regulations reg 55. This regulation was published/gazetted in November 2017 but didn’t come into effect until 14 May 2018, 10 days after this incident. It is critical, however, that all electrical contractors understand this change as simply responding to a customer’s request to leave part of an installation on is no longer good enough. There is an expectation that installations will be isolated from the main switch when completing this type of work or entering a roof space.
  • Both host employers and apprentices must ensure that isolation of circuits is completed with suitable test equipment. Volt stick type testers are for personal safety and should not be part of a formal isolation process.
  • EGT apprentices are to ensure the “test before you touch” principles are physically carried out including testing the tester before and after testing the circuit to prove the reliability of the tester.
  • Both host employers and apprentices must ensure they adhere to IITT testing procedures.

Feedback

  • An assumption was made that the cabling in the void was either power or lighting circuits.
  • Inadequate leadership/supervision – the tradesman failed to ensure the circuit was identified and isolated correctly.
  • The apprentice did not have his own meter on site and borrowed a volt stick that wasn’t fit for the purpose and failed to adequately check that it worked.
  • The apprentice did not ensure that the IITT processes were effectively carried out.

A personal message to apprentices
In each of the three electric shock incidents in 2018, inadequate test processes were a major factor.

If you don’t take charge of your safety, what guarantee is there that anyone else will – think before you work.

Feedback
For further information regarding this Safety Alert, please contact EGT on (08) 6241 6100.