Voer veilige stroomonderbreking uit
Koppel een circuit veilig los van zijn voeding voordat met elektrisch werk wordt begonnen.
Goal: Een circuit zodanig isoleren dat het niet opnieuw onder spanning gezet kan worden terwijl er aan gewerkt wordt.
Minimum practice time: 1 hour
Materials needed
- • Approved voltage indicator
- • MCB lock-off device
- • Personal lock and key
- • Warning tags
- • Proving unit (if available)
Safety first
- ! Never begin electrical work without confirming the circuit is dead
- ! Always use an approved voltage indicator — not a simple neon screwdriver
- ! Your personal lock must only be removed by you
- ! If the lock-off is not possible, post a competent person at the consumer unit
Steps8 total
- 1
Identify the circuit to be worked on
Find the circuit in the consumer unit. Check the circuit chart and confirm which MCB or fuse feeds the area you are working in.
Done when:You have identified the correct circuit breaker or fuse.
Why:Isolating the wrong circuit leaves you working on a live circuit.
- 2
Switch off the circuit breaker
Switch the MCB or remove the fuse for the identified circuit. The switch should be in the off position.
Done when:The MCB is in the off position or the fuse is removed.
Why:Switching off removes the supply to the circuit.
- 3
Lock off and tag the circuit breaker
Fit a lock-off device over the MCB. Attach your personal warning tag with your name and the date.
Done when:The MCB cannot be switched on by another person while your lock is in place.
Why:Lockout prevents someone else from switching the circuit on while you work.
- 4
Prove your voltage indicator works
Test your voltage indicator on a known live socket or circuit. Confirm it indicates voltage correctly.
Done when:Your voltage indicator shows a live reading on the test circuit.
Why:If your tester is faulty, you cannot trust a "dead" reading.
- 5
Test the isolated circuit
Test between live and neutral, live and earth, and neutral and earth at the point you will work on.
Done when:Your voltage indicator shows no voltage between all three conductor combinations.
Why:Testing all three combinations confirms the circuit is truly isolated.
- 6
Retest your voltage indicator
Test your voltage indicator again on the known live circuit.
Done when:The voltage indicator still works correctly.
Why:A second test confirms the indicator was working both before and after — your zero reading is reliable.
- 7
Apply warning notices
Hang a warning notice on the consumer unit saying: "Do not switch on — work in progress".
Done when:A warning notice is visible at the consumer unit.
Why:A warning notice informs other people not to restore power.
- 8
Inform nearby workers
Tell anyone working near the consumer unit that the circuit is isolated and why.
Done when:Nearby workers are aware of the isolation.
Why:Verbal communication reduces the risk of the circuit being accidentally re-energised.
Common mistakes to avoid
- × Testing only between live and neutral — always test all three combinations
- × Not proving the voltage indicator before and after the test
- × Forgetting to lock off the MCB and relying only on a switch-off
- × Not telling nearby workers about the isolation
Supervisor checklist
Confirm each item is completed before signing off.
- Correct circuit identified before isolation
- MCB locked off with a personal lock
- Voltage indicator proved working before and after testing
- Zero voltage confirmed between all conductor combinations
- Warning notice posted at the consumer unit
- Nearby workers informed
Evidence required
- • Supervisor witness statement confirming isolation procedure was carried out correctly
- • Photo of lock-off device and warning tag in place
Track this work card with a learner
Tick off steps, add evidence and register hours in Bloeiindex.