Dixell/Copeland AL31

What does Dixell/Copeland AL31 mean?

The AL31 alarm on the Dixell IC100CX iChill controller indicates a condenser pump flow or start-up alarm. It activates at the start-up of the condenser pump when the condenser water flow switch input does not close within the expected time, or transitions to a manual reset state if the no-flow condition persists. The alarm icon flashes on the display until the condition is resolved and the alarm is manually reset.

Symptoms

• AL31 displayed on the IC100CX with flashing alarm icon.
• Condenser pump may be running but flow switch input remains inactive.
• Alarm relay activates.
• System may delay or prevent compressor start to protect the condenser.

Common causes

• Condenser water pump failed to develop adequate flow at start-up.
• Condenser water flow switch requires longer time to close than the controller allows.
• Air-locked condenser circuit preventing pump from generating flow.
• Flow switch misadjusted — set threshold too high for installed pump flow rate.
• Condenser water pump rotation reversed — wired incorrectly on three-phase supply.

Diagnostic steps

1. 01

   Confirm condenser pump rotation and flow

   Verify the condenser pump is rotating in the correct direction. On three-phase motors, incorrect phase rotation causes reverse rotation and near-zero flow; check rotation by briefly running the pump and observing flow direction.

2. 02

   Test the condenser flow switch response time

   Time how long the condenser flow switch takes to close after pump start. If it consistently exceeds the start-up delay, increase the start-up delay parameter to match actual system response.

3. 03

   Purge air from the condenser circuit

   Open air vents at high points of the condenser water loop. An air-bound pump cannot develop rated flow; purging air restores normal operation.

4. 04

   Check flow switch calibration

   Confirm the flow switch paddle or vane is adjusted correctly for the actual condenser circuit flow rate. An over-sensitive setting will prevent the switch from closing at normal flow.

5. 05

   Manually reset and monitor

   After restoring condenser water flow, navigate to AlrM on the IC100CX, select AL31, and press SET to perform the manual reset. Monitor the flow switch input to confirm it stays closed during normal pump operation.

When to call a professional

Call a licensed HVAC/R technician if the condenser pump motor requires mechanical repair or if phase rotation correction requires re-wiring a three-phase supply — electrical work on three-phase circuits must be performed by a licensed electrician in most jurisdictions.