Electrical Troubleshooting and Safety Compliance Standards

Electrical Safety and Circuit Troubleshooting

Is a JSA required for electrical circuit troubleshooting?

Yes. As an employer, you have a duty of care to prevent workplace injuries and illnesses and to provide safe systems of work as specified under Section 19 of the Occupational Safety and Health Act 1984.

Example of a JSA hazard control measure

Hazard: Extension cord on a wet floor.

Control Measure: Secure cords to walls and hang them away from water sources.

• Likelihood: Likely
• Consequence: Major
• Risk Rating: Critical

Testing devices and applications

Device: Multimeter.

Application: Perform a continuity test on a faulty circuit.

Live vs. de-energised testing

Circuits should generally be tested de-energised to eliminate the high risk of equipment damage or personal injury.

Troubleshooting 3-way switching faults

If lights fail to operate at two of the mechanisms in a 3-way switching arrangement, the most probable fault is located in the intermediate switch.

AS/NZS 3000 compliance

Reference Table: Table C9 must be referenced regarding the maximum number of 10A single-phase double outlets on a 20A MCB/RCD.

Calculation: If 4 double socket outlets are currently connected, the maximum number of additional single socket outlets allowed is 2.

Common light circuit wiring methods

• Loop at light: Adopted when access to the ceiling is easier than the wall (e.g., brick walls).
• Loop at switch: Adopted when access to the wall is easier than the ceiling (e.g., gyprock walls).

Electrical system faults and rectification

15A socket outlets on a 20A MCB/RCD

If two 15A socket outlets are installed on a 20A MCB/RCD wired in 2.5mm² cable, this may cause an overload issue. Rectification: Ensure the circuit design complies with current-carrying capacity requirements and adjust the protection or cable size accordingly.

Hot Water System (HWS) boiling

Cause: Faulty thermostat.

Rectification: Replace the thermostat.

ELV downlight intermittent operation

Problem: Overheating of the light, a fault in the transformer, or poor connections/wiring.