What it means
The controller detected an interruption in power to the compressor or intermittent control power.
Behavior after power returns depends on machine configuration, including whether automatic restart after power failure is enabled.
Likely causes
- Facility power interruption or brownout
- Intermittent control power
- Loose or faulty electrical connections
Operator-safe first checks
- Confirm whether the facility experienced a power event at the same time.
- Treat the compressor as capable of automatic restart if that feature is enabled.
- Keep personnel clear of moving equipment while power is restored.
Trained maintenance / service checks
- Check line/control voltage quality and electrical connections.
- Review event history for repeated interruptions or brownouts.
Can the compressor keep running?
Do not assume the machine will remain stopped after power returns. Verify the configured restart behavior before approaching moving components.
Source confidence
OEM VERIFIED
Sullair describes Power Interruption as an interruption in compressor power and links the troubleshooting condition to intermittent control power.
Source: Sullair STS Controller User Manual, part 02250241-178 R01. Referenced manual page(s): 20, 33, 35.