Carel AL013

What does Carel AL013 mean?

AL013 signals that a device on the µChiller pLAN network has gone offline. The controller detected a loss of communication with a connected module or expansion card during normal operation. This is a serious alarm that triggers an immediate automatic reset and halts the affected circuit until the network link is restored.

Symptoms

• Controller display flashes AL013 with an immediate alarm notification.
• Affected refrigerant circuit shuts down automatically.
• Buzzer activates and the Alarm button lights up on the user terminal.
• pLAN network communication indicator shows a fault condition.

Common causes

• Loose or damaged pLAN network cable between the main controller and expansion module.
• Faulty or powered-off expansion card or peripheral device.
• Incorrect network address configuration on the connected device.
• Power interruption to a remote module on the pLAN bus.

Diagnostic steps

1. 01

   Inspect pLAN wiring connections

   Check all network cables connecting the main µChiller controller to expansion modules. Reseat any loose connectors and inspect for damaged insulation or broken conductors.

2. 02

   Verify device power supply

   Confirm that the offline device has power by checking its indicator LEDs. Measure supply voltage at the device terminals and compare to the rated specification.

3. 03

   Check pLAN network addresses

   Enter the manufacturer programming level and verify that each connected device has a unique, correctly assigned network address. Duplicate addresses cause communication failures.

4. 04

   Restart the controller and monitor alarms

   Power cycle the µChiller controller after correcting any wiring or configuration issues. Monitor the alarm log to confirm AL013 clears and does not recur.

When to call a professional

Call a licensed refrigeration technician if AL013 persists after verifying all pLAN wiring and address settings. Diagnosing faulty expansion boards, replacing network communication modules, or re-flashing firmware requires specialized Carel tools and authorization. Repeated offline alarms may indicate deeper electronic failure that can damage compressor circuits if left unresolved.