Electrical Safety, Codes, and Standards
What this domain tests
The legal and code framework for electrical work, the limits of a licence, safe isolation and permit-to-work discipline, and the standards underpinning design and inspection.
Core rules
- The Electricity Act and the Electricity (Electrical Workers) Regulations set the licensing grades - Electrician, Electrical Technician and Electrical Engineer - with defined scope and voltage limits for each. Work outside your grade is unauthorised even when you are competent.
- The Energy Market Authority administers licensing; installations must be inspected and tested by a licensed worker before energisation.
- SS 638 is the principal installation standard; SS 551 covers earthing, SS 650 temporary installations and SS 586 hazardous areas.
- The Workplace Safety and Health Act requires risk assessment, competent persons and control measures. Live work is prohibited unless de-energising is unreasonable, the risk is assessed and the work is authorised.
- Safe isolation: identify the circuit, isolate, lock and tag, prove the tester on a known source, prove dead at the point of work, then prove the tester again.
- Dangerous occurrences and accidents must be reported, and test records and certificates retained.
Worked example
A technician is asked to replace a three-phase isolator in a live riser. The correct response is to refuse live work, arrange a planned shutdown with the building owner, issue a permit-to-work, isolate upstream, lock and tag, prove dead on all phases and the neutral, and apply earths where the permit requires before starting.
Traps
- Assuming a licence permits work at any voltage or on any installation.
- Trusting a switched-off breaker without proving dead and locking off.
- Proving the voltage indicator only before use, never after.
- Overlooking permit and authorisation requirements in risers and switch rooms.