What is the correct sequence for safe isolation according to GS38?

GS38 procedure: identify circuit, isolate, secure against re-energisation, test voltage indicator on known live source, prove circuit dead, re-test indicator on live source.

Isolate, prove dead, secure, identify circuit, then re-test indicator

Identify circuit, isolate, secure, test voltage indicator, prove dead, re-test indicator

Prove dead, isolate, secure, identify circuit, then apply labels

Identify circuit, prove dead, isolate, secure, then test the indicator

Why must a voltage indicator be tested before and after proving dead?

Testing before proves it works, testing after confirms it didn't fail during the proving dead test - this validates the dead reading.

To calibrate the indicator against the supply voltage

To record the readings on the test certificate

To confirm the tester is working correctly and hasn't failed during use

To discharge any stored energy in the indicator

What is a proving unit used for?

A proving unit provides a known voltage source to test that voltage indicators are functioning correctly before and after use.

Measuring the earth fault loop impedance of a circuit

Discharging capacitors before working on equipment

Locating a hidden cable behind a wall

Providing a known voltage to test that the voltage indicator works

Free mock exam

Safe Isolation — AM2 Online Knowledge Test Practice

Free topic-focused mock exam: 15 random questions from a pool of 15 on Safe Isolation, drawn from the wider AM2 Online Knowledge Test bank. 25-minute timer, 70% to pass, worked explanation on every question. Use this when you've taken the full mock once and want to drill the topics you got wrong.

Questions: 15
Time limit: 25
Pass mark: 70%
Bank size: 15

Free · no sign-up · timer can be ignored · retake as many times as you want

Sample questions

01What is the correct sequence for safe isolation according to GS38?
- A.Prove dead, isolate, secure, identify circuit, then apply labels
- B.Identify circuit, prove dead, isolate, secure, then test the indicator
- C.Isolate, prove dead, secure, identify circuit, then re-test indicator
- D.Identify circuit, isolate, secure, test voltage indicator, prove dead, re-test indicator
Why: GS38 procedure: identify circuit, isolate, secure against re-energisation, test voltage indicator on known live source, prove circuit dead, re-test indicator on live source.
02Why must a voltage indicator be tested before and after proving dead?
- A.To record the readings on the test certificate
- B.To calibrate the indicator against the supply voltage
- C.To confirm the tester is working correctly and hasn't failed during use
- D.To discharge any stored energy in the indicator
Why: Testing before proves it works, testing after confirms it didn't fail during the proving dead test - this validates the dead reading.
03What is a proving unit used for?
- A.Discharging capacitors before working on equipment
- B.Measuring the earth fault loop impedance of a circuit
- C.Locating a hidden cable behind a wall
- D.Providing a known voltage to test that the voltage indicator works
Why: A proving unit provides a known voltage source to test that voltage indicators are functioning correctly before and after use.

FAQ

Is the Safe Isolation mock exam free?

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Can I retake the mock exam?

Yes. Every attempt picks a different random selection and reshuffles the options, so each retake gives you genuinely new questions. No limit on retakes.

Does this count towards the real qualification?

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