What does Power Interruption mean on a Sullair compressor?
Short answer: Control power was interrupted. If your Sullair WS Controller is showing Power Interruption, the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
The controller detected an interruption in control power. Note that with an auto-restart timer set, the compressor may restart automatically after power returns.
Which machines show this?
Sullair's mid-range stationary rotary screws fitted with the WS controller — a text-display unit found on many shop and light-industrial packages from the 2010s. The WS names its faults in plain English (High Temperature, Separator dP High, Aux Motor Overload, Power Interruption) and uses staged temperature protection: a warning at 225 °F, a time-delayed fault at 235 °F, and an immediate trip at 255 °F. Faults are reset from the STOP key after the cause is corrected and the unit has cooled. Practical tip: if the auto-restart timer is configured, the machine can start by itself after a power interruption — make sure nobody is working near it before you walk away from a Power Interruption message.
What causes it?
- A facility power blip or outage interrupting control power
- Repeated interruptions from a supply or connection problem
Can you fix it yourself?
Partly — confirm the facility event and log repeat times. Mind the auto-restart: the machine can start on its own when power returns.
Step by step — what to try, in order:
- Check whether the facility had a power blip or outage at the fault time
- Verify no one is working near the machine before resetting — it can restart on its own
- If interruptions are frequent, log the times and check them against other equipment cycling
When do you need a technician — and why?
Control power that drops with no facility-wide outage needs an electrician to test line voltage and connections — intermittent supply faults need instruments.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does Power Interruption mean on a Sullair WS Controller?
Control power was interrupted. The controller detected an interruption in control power. Note that with an auto-restart timer set, the compressor may restart automatically after power returns.
Can I fix Power Interruption on a Sullair WS Controller myself?
Partly — confirm the facility event and log repeat times. Mind the auto-restart: the machine can start on its own when power returns.
When does Power Interruption on a Sullair WS Controller need a technician?
Control power that drops with no facility-wide outage needs an electrician to test line voltage and connections — intermittent supply faults need instruments. Call an electrician if control power drops repeatedly with no facility-wide outage — line voltage and connections need testing.
Verified against service documentation: Sullair WS Controller documentation for Power Interruption (best-aire.com)