Proving unit
A portable source used to check that a responds before and after testing a circuit for dead. The first check catches a faulty indicator; the second shows it still worked after the dead reading. It is part of the prove-test-prove sequence, not a source that makes the circuit safe.
Using Proving unit in context
Updated
A distinction worth remembering
A proving unit checks the voltage indicator. It does not isolate the circuit or prove the circuit dead by itself.
Questions to take further
- How can I revise Proving unit beyond the definition?
- Explain what Proving unit describes, compare it with a related term and use it in a topic question. State any assumptions and what evidence you would need before applying the idea to real work.
Sources
- HSE: electrical safety questions — Isolation, competence and precautions before electrical work.
- HSE: GS38 test equipment guidance — Choosing and maintaining suitable low-voltage test equipment.
Where Proving unit fits in the learning path
The Sparks Basics section covers these units:
- Working Safely
Curriculum mapping: C&G 2365 Unit 201.
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- Safe Isolation ProcedureSparks Basics
- Voltage Indicator vs MultimeterSparks Basics
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- Safe Isolation — quiz previewFree · Sparks Basics
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A two-pole instrument used to check for voltage between conductors during safe isolation. The user checks it on a known live source or proving unit before and after testing the circuit. A suitable indicator and sound probes matter because a false dead reading can expose someone to live parts.
Voltage indicator
Read the Voltage indicator entryCompare related terms
Open a meaning to compare its role with Proving unit, or follow its full entry.
Voltage indicator
A two-pole instrument used to check for voltage between conductors during safe isolation. The user checks it on a known live source or proving unit before and after testing the circuit. A suitable indicator and sound probes matter because a false dead reading can expose someone to live parts.
Read the Voltage indicator entrySafe isolation
The procedure that proves a circuit dead before anyone works on it. Prove the voltage indicator against a known source, isolate the circuit, secure the isolation with your own lock and tag, prove the point of work dead across all conductor combinations, then prove the indicator again. The final step is the one that catches a tester that died mid-job.
Read the Safe isolation entryGS38
HSE guidance on electrical test equipment used on low-voltage systems. It covers choosing and maintaining suitable instruments, probes and leads, including insulation, finger barriers and limiting exposed metal. Describing equipment as GS38-compliant is not a guarantee about its condition or use: the whole test arrangement and working method must suit the task.
Read the GS38 entryA definition is a start. Using it in a real question is where it sticks.