SULLAIR-HIGH-SUMP-PRESSURE critical Sullair WS Controller

High Sump Pressure — Control/Valve Fault

The SULLAIR-HIGH-SUMP-PRESSURE (Sullair WS Controller) diesel fault code means: High Sump Pressure — Control/Valve Fault. This is a critical severity code.

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Common Symptoms

  • WS display shows High Sump Pressure
  • Machine may fault and blow down

Probable Causes (Ranked by Likelihood)

  • Poppet, Sullicon, spiral, blowdown or pneumatic valve failed High
  • Faulty solenoid valve(s) Moderate
  • Faulty or misadjusted pressure regulator Moderate
  • Minimum pressure check valve fault (not applicable to Fluid Free machines) Low

Step-by-Step Diagnostic Procedure

  1. The WS Controller is fitted to Sullair STATIONARY electric shop compressors. Portable towable Sullair units (185-class and similar) use different engine-driven controls and a different fault system — this page does not apply to them.

  2. Check the control valves (poppet / Sullicon / spiral / blowdown / pneumatic) for correct operation.

  3. Check Sullicon adjustment per the Control Adjustment section of the compressor operator's manual.

  4. Check solenoid valve operation and wiring.

  5. Check pressure regulator adjustment and operation, and the minimum pressure check valve (except Fluid Free units).

  6. Factory limits for this condition: P1 fault limit by class: 135/150/175/200 psig (100/125/150/175 psig machines)

  7. Per the factory manual: after resolving a fault condition, press the STOP pad to clear the FAULTED state. If the problem persists after the recommended checks, consult your Sullair distributor or factory service.

Frequently Asked Questions

What are the sump pressure fault limits?

They depend on the machine's pressure class — per the manual: 135 psig on a 100 psig machine, 150 on a 125, 175 on a 150, 200 on a 175 psig machine (VSD classes differ slightly). The controller faults when sump pressure (P1) exceeds the limit for your class.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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