What causes fault code VFD-MOL1 (VFD Motor Overload)?

Mechanical load increased — bearing failure, product buildup, or process change. Motor overload parameter set too low — should be set to motor nameplate FLA. Ambient temperature at motor above rated — motor service factor consumed. Motor cooling fan broken or blocked — TEFC fan shroud clogged. Running motor at low speed for extended time — reduced cooling at low RPM on self-cooled motors

How do I fix fault code VFD-MOL1?

Check motor nameplate FLA and verify VFD motor overload parameter matches. Measure actual motor current with clamp meter — compare to FLA. Check motor surface temperature with IR gun — should not exceed nameplate insulation class rating. Inspect motor fan and fan shroud — clear debris, verify fan spins freely. If running continuously below 30Hz on a TEFC motor, add a forced-cooling blower kit. Check mechanical load — rotate shaft by hand with motor disconnected, feel for binding

VFD Motor Overload

VFD-MOL1

VFD electronic motor overload protection tripped. Motor current exceeded the programmed overload threshold for the programmed time.

medium vfd conveyor packaging palletizer

vfd motor overload thermal fan cooling

Probable Causes (ranked)

Mechanical load increased — bearing failure, product buildup, or process change
Motor overload parameter set too low — should be set to motor nameplate FLA
Ambient temperature at motor above rated — motor service factor consumed
Motor cooling fan broken or blocked — TEFC fan shroud clogged
Running motor at low speed for extended time — reduced cooling at low RPM on self-cooled motors

Fix Steps

1 Check motor nameplate FLA and verify VFD motor overload parameter matches
2 Measure actual motor current with clamp meter — compare to FLA
3 Check motor surface temperature with IR gun — should not exceed nameplate insulation class rating
4 Inspect motor fan and fan shroud — clear debris, verify fan spins freely
5 If running continuously below 30Hz on a TEFC motor, add a forced-cooling blower kit
6 Check mechanical load — rotate shaft by hand with motor disconnected, feel for binding

Field Trick

If a motor runs fine for 2 hours then trips on overload, check the motor fan shroud first. A clogged shroud lets the motor slowly heat up until the thermal model trips. Cleaning the shroud takes 5 minutes and is the fix 40% of the time.

Suggested Replacement Parts

Parts matched to fault category: Motor

Baldor/ABB 1HP TEFC Motor P/N: EM3554T 1HP, 1765RPM, 143TC frame, 230/460V, TEFC, premium efficiency

AutomationDirect $285.00 Amazon $310.00 Grainger $345.00

Prices are estimates. Verify part numbers match your equipment before ordering.

Need a deeper diagnosis with photo analysis and AI-powered troubleshooting?

Run Full Diagnosis