VSDs
Drive faults, start commands, and trip codes.
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.
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.
VSD trips on DC bus overvoltage
The drive trips on overvoltage — usually during deceleration or stopping, when a spinning load pushes energy back into the DC bus faster than it can be absorbed.
VSD trips on undervoltage / loses supply
The drive trips on undervoltage — the DC bus drops too low, often on start, under load, or with supply dips, and the drive shuts down to protect itself.
VSD trips on over-temperature
The drive trips on over-temperature — usually after running a while, in hot conditions, or under heavy load, because it can't shed heat fast enough.
VSD trips on earth/ground fault
The drive trips with an earth/ground-fault code — typically the instant it outputs — indicating leakage to earth on the motor or output cabling.
VSD runs but motor doesn't reach set speed
The drive shows it's running and outputting, but the motor turns slowly, sluggishly, or never reaches the commanded speed.
VSD display blank / drive appears dead
The drive's display is blank and it shows no signs of life — no keypad, no LEDs — so nothing can be operated or diagnosed from the panel.
VSD communication / fieldbus fault
The drive has lost communication with the PLC/SCADA over its fieldbus (e.g. control by network) — comms-loss fault, no remote control, or the drive stops on comms timeout.
VSD nuisance tripping with no obvious cause
The drive trips intermittently with codes that don't seem to match the conditions — random faults, hard to reproduce, often noise- or connection-related.
Motor noisy or whining when run on a VSD
The motor runs but is noticeably noisy on the drive — a whine, whistle, or growl that isn't there on direct supply, sometimes worse at certain speeds.
VSD keeps tripping the RCD / safety switch
The upstream RCD drops out when a drive is powered up or ramped — the drive itself shows no fault. Drives leak to earth by design (EMC filters and long screened cables), and standard RCDs don't always get along with them.
VSD reports output phase loss / motor phase loss
The drive trips or warns of an output (motor) phase loss — it isn't seeing balanced current on all three output phases to the motor.
VSD trips on overcurrent only during acceleration
The drive runs steadily once up to speed, but throws an overcurrent (or 'OC on accel') fault each time it ramps up to speed. Runs fine if it gets there; trips on the way up.
VSD powered and fault-free but won't accept the run command
The drive is powered, shows no fault, and the display looks normal — but it ignores the run command and the motor never turns. Often a 'not ready' / 'STO' / enable status, not a trip.