Carel AL007

What does Carel AL007 mean?

AL007 on the Carel FLSTDmSCHE screw chiller controller indicates the real-time clock card is broken or not communicating with the pCO5 main board. The clock card is required for alarm logging with timestamps, time-band scheduling, and timed rotation of compressors and pumps. AL007 is a signal-only alarm with automatic reset — the chiller continues cooling, but time-dependent functions are unavailable.

Symptoms

• AL007 displayed on the pCO5 terminal; chiller continues running
• Alarm log timestamps absent or showing incorrect dates/times
• Time-band setpoint schedules and timed maintenance intervals not executing

Common causes

• Real-time clock battery depleted — the lithium battery backing the clock card has failed
• Clock card not seated correctly on the pCO5 or pCO3 board
• Clock card hardware failure — the module itself has failed
• Firmware update or parameter reset that disabled the clock card interface

Diagnostic steps

1. 01

   Check clock card seating

   Power down the chiller controller and inspect the optional clock board connector on the pCO5 main board. The clock card should be firmly seated with no bent pins. Re-seat it if loose.

2. 02

   Replace the clock battery

   The pCO5 clock card uses a replaceable lithium coin cell (typically CR2032). If the battery voltage is low or zero, replace it. The battery can be replaced with the controller powered on to preserve clock settings.

3. 03

   Set the correct date and time

   After battery replacement, navigate to the clock parameter screens on the pCO5 terminal and set the correct date and time. Reset all time-band programming that may have been lost.

4. 04

   Check for clock card module failure

   If the alarm persists after battery replacement and re-seating, the clock module itself may have failed. Test by replacing the clock card with a known-good unit.

5. 05

   Verify automatic reset

   AL007 resets automatically once the clock card communicates successfully. Confirm the alarm clears, the correct time is displayed, and alarm log entries now include timestamps.

When to call a professional

Battery replacement and clock card re-seating are straightforward tasks for a qualified controls technician. If the alarm persists after both steps, a Carel-authorized service technician should diagnose the pCO5 board interface. Continued operation without a working clock card means alarm timestamps and timed maintenance schedules are unreliable.