AdvancedHigh risk

VSD trips on overcurrent / overload

The drive trips with an overcurrent or overload code — on start, on acceleration, or under running load. It may restart and trip again on the same point in the cycle.

Start fault-finding

Safety first

Overcurrent trips can indicate a short or earth fault on the motor or cable. Prove dead and discharge the DC bus before testing output cabling. Never reset repeatedly into a hard fault.

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.

Full detail — causes, the why, and common mistakes.

Likely causes

Ranked from most to least likely.

1
Mechanical overload or jam on the driven equipment
Most likely
If the load is jammed, sticking, or the inertia is too high for the accel ramp, current spikes and the drive trips to protect itself and the motor.
2
Acceleration ramp too fast for the load
#2
A ramp time set shorter than the load's inertia can tolerate forces high current during accel and trips at the same point each time.
3
Output cable or motor fault (short / earth fault)
#3
A phase-to-phase or phase-to-earth fault in the motor or its cable causes an immediate overcurrent the instant the drive outputs.
4
Incorrect motor data / control mode
#4
Wrong nameplate parameters or an un-tuned vector mode makes the drive mis-estimate current and trip, especially at low speed.
5
Undersized drive for the duty
Least likely
A drive rated below the load's real demand will trip on legitimate peaks the application needs.

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

Premium fault tree

The full ranked causes, test sequence and flowchart for this fault are part of Sparkie Sidekick Pro.

Coming soon — no payment required during preview.

Testing sequence

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

Test 1 of 4

Note exactly when it trips — at the instant of output, during accel, or under steady load — and read the exact fault code/value.

Expected reading

A consistent trip point you can describe and a clear code.

Your actual reading

If it passes

Trip pattern points you to a cause group (instant=short, accel=ramp/inertia, load=mechanical).

If it fails

If it's random, suspect intermittent wiring or a marginal motor fault.

Often leads toVSD powered up but won't start the motor Motor overload keeps tripping

View all expected readings at once

1. Note exactly when it trips — at the instant of output, during accel, or under steady load — and read the exact fault code/value.

A consistent trip point you can describe and a clear code.

2. Isolate, lock off, discharge the bus, disconnect the motor cable at the drive, and test the motor + cable for shorts and earth faults per your procedure.

Balanced phase-to-phase readings and high insulation resistance to earth.

3. If it trips on accel, lengthen the acceleration ramp and re-test; if it trips under load, clamp output current vs the drive/motor rating.

With a longer ramp it accelerates cleanly; running current stays within rating.

4. Confirm the motor nameplate data entered in the drive is correct and re-run any auto-tune the manufacturer specifies.

Parameters match the nameplate and the tune completes without error.

Full test sequence

The step-by-step test flow with expected readings for this fault is part of Sparkie Sidekick Pro.

Coming soon — no payment required during preview.

Fault-finding flowchart

The same logic as a decision tree.

1
start
VSD trips on overcurrent
→ step 2
2
decision
Does it trip the instant it outputs (before the motor moves)?
Yes→ step 3No→ step 4
3
result
Suspect a motor/cable short or earth fault. Isolate and insulation-test before re-running.
4
decision
Does it trip during acceleration?
Yes→ step 5No→ step 6
5
result
Lengthen accel ramp / check inertia and motor data + tune.
6
decision
Is running current within drive/motor rating?
Yes→ step 7No→ step 8
7
result
Check motor data/control mode and drive sizing for the duty.
8
result
Genuine overload on the driven equipment — hand to mechanical.

Common mistakes apprentices make

Resetting into a hard overcurrent repeatedly, risking the drive and motor.
Blaming the drive when the driven machine is mechanically jammed.
Shortening accel ramps to 'speed things up' and then chasing the resulting trips.
Skipping motor/cable insulation tests after an instant-on overcurrent.

When to stop & escalate

Confirmed motor or cable short/earth faults, or a load that is genuinely overloaded, should go to the appropriate repair/mechanical team. Repeating drive faults that don't match wiring or load findings should be taken to the manufacturer's documentation/support with the exact code.

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.

Related faults

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VSD powered up but won't start the motor

The drive is energised and the display is alive, but it won't run the motor. No fault may be shown — it just sits in 'ready' or 'stopped' and ignores the start command.

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Motors & overloads

Motor overload keeps tripping

The thermal/electronic overload trips repeatedly, either on start or after the motor has run for a while. Resetting only buys you a short run before it trips again.

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General testing

Three-phase equipment single-phasing (lost a phase)

Three-phase equipment is misbehaving — motors humming, struggling, overheating, or tripping — because one phase has been lost somewhere between the supply and the load.

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Learn the theory

How the gear and circuits behind this fault actually work.

Device

VSD (Variable Speed Drive)

Controls the speed of an AC motor by converting the supply to a variable frequency and voltage.