EL
ErrorLib
Brands
||
  1. Home
  2. Yaskawa
  3. iQpump Simplex Pump Drive
  4. LOP
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

LOP

Loss of Prime Fault

Yaskawa · iQpump Simplex Pump Drive

What does LOP mean?

The iQpump has detected a loss of prime condition within the pump. This fault occurs when the output current drops below the level set in parameter P1-14, while the output frequency is at its maximum. This condition must persist for the time specified in parameter P1-12 before the iQpump triggers the fault and coasts to a stop.

Common Causes

  • Output current dropping below the P1-14 (Prime Loss Level) threshold due to lack of water.
  • Pump operating at maximum output frequency (e.g., 60 Hz) while drawing very low current.
  • Insufficient water supply to the pump suction inlet.
  • Air ingress into the pump casing or suction line.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify parameter P1-14 (Prime Loss Level) is set correctly based on the pump's no-load or dry-run current.

  2. 2

    Verify parameter P1-12 (Not Maintaining Set-Point Delay Time) is appropriate for detecting a sustained low-current condition.

  3. 3

    Check the pump's suction line, foot valve, and impeller for blockages, air leaks, or damage.

  4. 4

    Ensure the water source is adequate and the pump has been properly primed (filled with liquid).

Browse all codes in this manual (7)
Verified technical data. Last updated: April 2026

Related Faults

HFBHigh Feedback FaultLFBLow Feedback Level AlarmLFB/LWLow Feedback/Water Fault
Source: Yaskawa iQpump Simplex Pump Drive
Open Manual (Page 3)Search more codes in this manual