The disciplined sequence for proving a circuit dead before working on or near it.
Working on or near electrics without proving they are dead is one of the most dangerous things you can do. Use this as a revision checklist of the safe-isolation principle; live electrical work must be carried out by a competent person to the current standards.
- Identify the correct circuit. Be sure which circuit feeds the equipment, so you isolate the right one and do not leave it live by mistake.
- Switch off and isolate at the point of isolation, for example the correct circuit breaker or isolator.
- Lock off and label. Secure the isolation with a lock and a warning notice so nobody can switch it back on while you work.
- Prove your tester works. Check your approved voltage indicator against a known source or proving unit first.
- Prove dead. Test the conductors to confirm there is no voltage present, then test your indicator again to confirm it still works.
- Only then work. Treat the circuit as live until you have personally proved it dead.
The discipline is identify, isolate, secure, prove dead, prove the tester again. Electrical installation work in dwellings is controlled under Approved Document P, and where you are not competent to carry out the electrical work it must be done by someone who is. Confirm the full procedure against current guidance.
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