What it means
The main starter failed to operate or the expected starter feedback was not received.
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
- Main starter failed to operate
- Faulty auxiliary contact
- Momentary line-power loss or brownout
Operator-safe first checks
- Record whether site power flickered or other equipment was affected.
- Do not attempt repeated starts if the starter is chattering or power quality is unstable.
Trained maintenance / service checks
- Inspect starter/control wiring and auxiliary contacts.
- Check line-power quality for momentary loss or brownout.
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.