What it means
The controller did not receive the expected starter/contact feedback for the pump motor.
This entry is tied to the exact STS message family documented by Sullair. The same words can mean something different on another controller generation, so confirm the displayed message and machine documentation before acting.
Likely causes
- Pump starter failed to operate
- Faulty auxiliary contact
- Control-wiring problem
Operator-safe first checks
- Record whether the pump actually started and any related overload message.
- Do not bypass starter feedback circuits.
Trained maintenance / service checks
- Inspect pump starter and control wiring.
- Check the auxiliary contact and its wiring for correct operation.
Reset or keep running?
Do not use repeated resets as a substitute for diagnosis. If the condition involves electrical power, a motor overload, high pressure, loss of cooling, abnormal temperature, or a safety circuit, correct the underlying problem before returning the compressor to service.
Source confidence
OEM VERIFIED
This message and its troubleshooting direction are traced to the Sullair STS controller troubleshooting guide.
Source: Sullair STS Controller User Manual, part 02250241-178 R01. Referenced manual page: 34.