What does P1 Sump Pressure High mean on a Sullair Supervisor?
Short answer: Sump pressure high trip. If your Sullair Supervisor Controller is showing P1 Sump Pressure High, 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?
Sump pressure exceeded its limit (e.g., 135 psig on a 100 psig machine), typically from a failed poppet, Sullicon, spiral, blowdown, or pneumatic valve, faulty solenoid valves, or a misadjusted pressure regulator.
Which machines show this?
older large-frame Sullair rotary screw compressors — flooded-screw and two-stage industrial packages from the Supervisor era, many still running in plants today. The Supervisor reports by channel: temperatures are T1 through T5, pressures P1 through P4, and differential pressure dP1, so a fault reads like 'T2 Discharge High' or 'P1 Sump Pressure High' rather than a code number. Flooded screws warn at 225 °F on T1 and fault at 235 °F delayed or 255 °F immediate; sensor failures are flagged when a channel reads an impossible value. Practical tip: always record which channel number tripped — T-numbers and P-numbers map to specific probes on the machine, and that number is the first thing a Sullair technician will ask for.
What causes it?
- Failed poppet, Sullicon, spiral, blowdown, or pneumatic valve
- Faulty solenoid valves
- Pressure regulator misadjusted
Can you fix it yourself?
No — stop, blow down completely, restart once while watching pressure control, and record the numbers. That's the in-house limit.
Step by step — what to try, in order:
- Stop the unit and let it blow down completely
- Restart once and watch whether pressure control behaves normally
- Record operating pressures before/at the trip for the technician
When do you need a technician — and why?
Control valve and regulator diagnosis on a pressurized sump is professional work; a 100 psig machine tripping at 135 psig is not a nuisance alarm.
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 P1 Sump Pressure High mean on a Sullair Supervisor Controller?
Sump pressure high trip. Sump pressure exceeded its limit (e.g., 135 psig on a 100 psig machine), typically from a failed poppet, Sullicon, spiral, blowdown, or pneumatic valve, faulty solenoid valves, or a misadjusted pressure regulator.
Can I fix P1 Sump Pressure High on a Sullair Supervisor Controller myself?
No — stop, blow down completely, restart once while watching pressure control, and record the numbers. That's the in-house limit.
When does P1 Sump Pressure High on a Sullair Supervisor Controller need a technician?
Control valve and regulator diagnosis on a pressurized sump is professional work; a 100 psig machine tripping at 135 psig is not a nuisance alarm. Call a service technician — control valve and regulator diagnosis on a pressurized sump is professional work.
Verified against service documentation: Sullair Supervisor Controller documentation for P1 Sump Pressure High (best-aire.com)