Dixell/Copeland AL04

What does Dixell/Copeland AL04 mean?

The AL04 alarm on the Dixell IC100CX iChill controller is a general alarm triggered when the associated digital input is not active. The controller activates the buzzer, lights the general alarm icon, and closes the alarm relay output. This alarm is disabled for a start-up delay period from compressor activation to prevent nuisance trips during system start-up transients.

Symptoms

• AL04 displayed on the IC100CX screen.
• Buzzer activated and general alarm icon lit on the display.
• Alarm relay output closes.
• The triggering digital input reads inactive (open circuit) on the controller.

Common causes

• External device wired to the general alarm digital input has opened its contact.
• Wiring fault — broken or disconnected wire to the digital input terminal.
• Associated external safety device (e.g., high-pressure switch, flow switch) has tripped.
• Incorrect digital input polarity configuration — input configured as normally closed but wired normally open.

Diagnostic steps

1. 01

   Identify the digital input source

   Access the IC100CX digital input status screen to identify which input is inactive. Cross-reference with the wiring diagram to find the connected external device.

2. 02

   Inspect the external device

   Locate and inspect the device wired to the AL04 digital input. Check for a tripped thermal protection, open high-pressure switch, or flow switch that has dropped out.

3. 03

   Check wiring continuity

   Use a multimeter to check continuity from the external device contact through to the IC100CX digital input terminal. An open reading with the device in its normal state indicates a wiring break.

4. 04

   Verify input polarity configuration

   Confirm the digital input is configured for the correct contact type (normally open or normally closed) in the IC100CX parameters. A mismatch will cause a permanent false AL04 alarm.

5. 05

   Reset the alarm after correcting the fault

   Navigate to AlrM in the function menu, select AL04, and press SET to execute the reset once the triggering condition is resolved and the digital input is active again.

When to call a professional

Call a licensed technician if the external device tied to the AL04 input is a refrigerant safety control (high-pressure switch, oil pressure switch) that has tripped and requires root cause investigation, or if parameter reconfiguration of digital input polarity or function assignments is beyond your access level on the controller.