QualifiedMedium risk

Power point reads voltage but the appliance won't run

You measure roughly normal voltage at the GPO, but plug in an appliance and nothing happens. The point isn't 'dead' on the meter, yet it won't drive a load.

Safety first

A point that reads voltage but can't supply current may have a broken neutral or a high-resistance joint that's live and dangerous. Treat it as live, and isolate before opening the accessory.

Isolate, lock out / tag out, and prove dead before working unless a live test is specifically required, authorised, and carried out under proper supervision. Always follow local regulations, your site procedures, and the equipment manufacturer's documentation.

Apprentice mode

Full walk-through — the why, what readings mean, mistakes & safety.

Likely causes

Ranked from most to least likely.

  1. 1

    Open or high-resistance neutral

    Most likely

    With an open neutral, a high-impedance meter still reads near-full voltage active-to-neutral through the appliance/parallel paths, but no real return path exists so no current flows and the appliance stays dead.

  2. 2

    Phantom voltage on a disconnected active

    #2

    Capacitive coupling from adjacent live cables induces a voltage a sensitive meter reads, even though the conductor isn't actually connected to a source that can deliver current.

  3. 3

    High-resistance active connection

    #3

    A loose or corroded active joint holds voltage with no load but collapses the instant the appliance draws current, so nothing runs.

  4. 4

    Faulty appliance or its lead

    Least likely

    The point may be fine — a tripped appliance thermal cutout, blown appliance fuse, or broken flex means the appliance won't run regardless.

Reports are saved on this device to reflect what you actually find.

Testing sequence

Work through one test at a time. Expected reading and what each result means.

On the tools? Job Mode shows one test at a time with thumb-sized buttons — your place and readings carry straight over.

Enter Job Mode
Test 1 of 3
1

Re-measure with a loading-type tester (low-impedance) rather than only a high-impedance multimeter.

Expected reading

A loading tester confirms whether the voltage is a real, load-capable supply or a phantom.

If it passes

Voltage holds under the tester's load — the supply is real, so look at the appliance/lead or a connection that sags under heavier load.

If it fails

Voltage collapses under the tester — it was phantom or a high-resistance/open conductor, not a usable supply.

Mark this test
View all expected readings at once
1. Re-measure with a loading-type tester (low-impedance) rather than only a high-impedance multimeter.
A loading tester confirms whether the voltage is a real, load-capable supply or a phantom.
2. Measure active-to-earth and neutral-to-earth at the point.
Active-to-earth near nominal, neutral-to-earth close to zero.
3. Try a known-good appliance/test lamp at the point; isolate and check the GPO terminations.
A known-good load runs and terminations are tight.

Fault-finding flowchart

The same logic as a decision tree.

  1. 1
    start

    GPO reads voltage but appliance won't run

    → step 2
  2. 2
    decision

    Does voltage hold under a loading tester?

    Yes→ step 3No→ step 4
  3. 3
    decision

    Is neutral-to-earth close to zero?

    Yes→ step 5No→ step 6
  4. 4
    result

    Phantom or high-resistance/open conductor — trace the broken active/neutral.

  5. 5
    result

    Supply is real — the appliance or its lead is faulty. Prove with a known-good load.

  6. 6
    result

    Lost / high-resistance neutral upstream — trace and repair the neutral path.

Common mistakes apprentices make

  • Trusting a high-impedance multimeter reading and declaring the point 'good'.
  • Not checking neutral-to-earth, missing a lost neutral.
  • Blaming the appliance before proving the point can actually supply current.
  • Forgetting that a phantom voltage can't drive a load — the reading is misleading.

When to stop & escalate

A lost neutral can make exposed metalwork live elsewhere on the installation — if you suspect one, stop and investigate the shared neutral path before energising anything. Escalate if the fault is upstream of the point in an inaccessible part of the installation.

If you're past your competence, authorisation, or the safe limits of the job — stop and hand it on. There's no fault worth getting hurt over.

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