Under the Electricity at Work Regulations 1989 Reg 14, live working is only permitted when:

EAWR 1989 Reg 14 imposes three cumulative tests. All three must be met; failing any one makes live working a criminal offence under the Regulations.

The supply voltage does not exceed 230V AND the circuit is protected by a 30mA RCD AND the worker holds a current ECS card

It is unreasonable in all the circumstances to make dead, AND it is reasonable to work live, AND suitable precautions are taken

The duty holder has issued a written permit-to-work AND a second competent person is present AND the work lasts no longer than one hour

It would cause unacceptable disruption to make dead, OR the client refuses isolation, OR insulated tools are available on site

The correct sequence for safe isolation in accordance with HSG85 and the Electrical Safety First Best Practice Guide 2 is:

Best Practice Guide 2 requires the identify-isolate-secure then prove-test-prove sequence, using an approved GS38-compliant two-pole voltage indicator (NOT a multimeter) and a known live proving unit.

Switch off, test dead with a multimeter, lock off and apply a caution notice once confirmed dead

Identify circuit, prove the indicator dead, isolate, test the circuit, then lock off afterwards

Identify, switch off, secure isolation, prove indicator live, test for absence of voltage, re-prove live

Lock off the supply, test for voltage, prove the indicator live, then switch off and apply notices

Which test instrument is the ONLY device acceptable for proving dead during safe isolation?

HSE GS38 requires a dedicated two-pole voltage indicator with finger-barriers, fused tips, and probes exposing no more than 4mm of metal. Multimeters and neons are explicitly unsafe.

A digital multimeter set to the AC voltage range, provided the leads carry GS38-compliant fused probes

A non-contact voltage detector (volt-stick), as it requires no physical contact with live parts

A mains-test neon screwdriver, provided it is checked against a known live source first

Two-pole approved voltage indicator complying with GS38 (e.g. Martindale VI-13800, Drummond MTL10)

Free mock exam

Level 3 Inspection, Testing & Commissioning Mock Exam

Free mock exam for Level 3 Electrical apprentices on Inspection, Testing and Commissioning. 25 questions from a 201-question bank covering the BS 7671 testing sequence per GN3, initial verification, periodic inspection (EICR), RCD test methods, MFT use, polarity, continuity, insulation resistance and the certification process.

Questions: 30
Time limit: 35 min
Pass mark: 70% · 21/30
Question bank: 200

Free, no sign-up. Retake as many times as you like — different questions each time.

Sample questions

01Under the Electricity at Work Regulations 1989 Reg 14, live working is only permitted when:
- AIt would cause unacceptable disruption to make dead, OR the client refuses isolation, OR insulated tools are available on site
- BIt is unreasonable in all the circumstances to make dead, AND it is reasonable to work live, AND suitable precautions are taken
- CThe supply voltage does not exceed 230V AND the circuit is protected by a 30mA RCD AND the worker holds a current ECS card
- DThe duty holder has issued a written permit-to-work AND a second competent person is present AND the work lasts no longer than one hour
Why: EAWR 1989 Reg 14 imposes three cumulative tests. All three must be met; failing any one makes live working a criminal offence under the Regulations.
02The correct sequence for safe isolation in accordance with HSG85 and the Electrical Safety First Best Practice Guide 2 is:
- AIdentify circuit, prove the indicator dead, isolate, test the circuit, then lock off afterwards
- BLock off the supply, test for voltage, prove the indicator live, then switch off and apply notices
- CSwitch off, test dead with a multimeter, lock off and apply a caution notice once confirmed dead
- DIdentify, switch off, secure isolation, prove indicator live, test for absence of voltage, re-prove live
Why: Best Practice Guide 2 requires the identify-isolate-secure then prove-test-prove sequence, using an approved GS38-compliant two-pole voltage indicator (NOT a multimeter) and a known live proving unit.
03Which test instrument is the ONLY device acceptable for proving dead during safe isolation?
- AA non-contact voltage detector (volt-stick), as it requires no physical contact with live parts
- BTwo-pole approved voltage indicator complying with GS38 (e.g. Martindale VI-13800, Drummond MTL10)
- CA digital multimeter set to the AC voltage range, provided the leads carry GS38-compliant fused probes
- DA mains-test neon screwdriver, provided it is checked against a known live source first
Why: HSE GS38 requires a dedicated two-pole voltage indicator with finger-barriers, fused tips, and probes exposing no more than 4mm of metal. Multimeters and neons are explicitly unsafe.

Common questions

Is the Level 3 Inspection, Testing & Commissioning mock exam free?

Yes — 100% free, no sign-up needed. Questions are pulled at random from a substantial bank, with a worked explanation on every question after you submit.

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?

No — this is independent practice material. To gain the actual qualification you need to sit the official assessment through an approved provider.