Safe Isolation Procedure
Sparks Basics · C&G 2365 Unit 201 · Free section
Every year electricians are injured working on circuits someone believed were dead. The procedure exists so that belief is never the thing protecting you: you prove your tester works, isolate and secure the supply with your own lock, prove the circuit dead at the point of work, then prove your tester again.
HSE guidance note describes what a suitable voltage indicator and proving unit look like — fused leads, finger barriers, minimal exposed probe tips. Our lessons walk the single-phase three-test check and the full three-phase ten-point sequence until the order is muscle memory.
questions appear in C&G 2365 health-and-safety assessments and in AM2 practical tests, and interviewers love asking for the sequence out loud. If you can teach it back, you own it.
Common questions
- Is there a free Safe Isolation Procedure quiz?
- Yes. Procedure is taught in the Sparks Basics section of TradeTraining, which is free — you can practise in your browser without paying anything.
- Where does Safe Isolation Procedure sit in the City & Guilds scheme?
- Procedure maps to C&G 2365 Unit 201. On TradeTraining it lives in the Sparks Basics section as bite-size lessons with practice questions.
- What are the basic steps of safe isolation?
- Identify the circuit, prove your voltage indicator on a proving unit, isolate the supply, secure it with your own lock and warning tag, prove the point of work is dead on all conductor combinations, then re-prove your indicator. If the tester fails the final prove, the dead reading means nothing — start again.
- What is a proving unit for?
- A proving unit is a pocket-sized known voltage source. Testing your voltage indicator against it before and after checking a circuit proves the indicator itself is working — otherwise a broken tester and a live circuit read exactly like a dead one.