What it means
One of the monitored compressor temperature channels is below its configured low-temperature condition.
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
- Low ambient air temperature
Operator-safe first checks
- Record which temperature channel is named and the ambient condition.
- Avoid forcing a cold machine into load before the machine-specific warm-up requirements are met.
Trained maintenance / service checks
- For cold environments, verify whether a sump heater is required for the package.
- Confirm temperature sensing is plausible if the reading does not match actual conditions.
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: 33.