Ako F0

What does Ako F0 mean?

F0 defines the evaporator fan shutdown temperature on AKO controllers equipped with a second probe (evaporator probe, S2). When the evaporator temperature measured by S2 drops to or below the F0 value, the fans stop to prevent excessive cold-air circulation or frost accumulation. The fans restart when the evaporator temperature rises above F0 minus the F1 differential. This is a normal operating parameter, not a fault code.

Symptoms

• Evaporator fans stop when S2 reads at or below the F0 setpoint.
• Fans restart when S2 rises above F0 minus F1 differential.
• If F0 is set incorrectly high, fans may stop too soon, reducing cooling efficiency.
• If F0 is set incorrectly low, fans may run continuously across the coil even when iced.
• If probe S2 fails (E2), F0 and F1 are bypassed and fans run continuously.

Common causes

• F0 parameter value set incorrectly during commissioning — too high causes premature fan shutdown.
• F0 and F1 interaction: F1 differential too narrow causes fan short-cycling.
• Probe S2 fault (E2) disabling the F0 function entirely.
• Default F0 value (typically +4 °C) may be inappropriate for deep-freeze applications requiring sub-zero fan shutdown.

Diagnostic steps

1. 01

   Verify F0 setting matches the installation requirements

   Check the current F0 value against the commissioning specification. For medium-temperature cold rooms, F0 is typically set at +4 °C. For low-temperature freezers, a lower value matching the evaporator operating temperature is required.

2. 02

   Verify F1 differential is correctly set

   Confirm F1 (probe 2 differential) is set wide enough to prevent fan short-cycling. F1 is subtracted from F0 to determine the fan restart temperature; a very small F1 causes rapid on/off cycling.

3. 03

   Check probe S2 status

   Verify S2 is functioning correctly (no E2 alarm). If S2 is faulted, F0 fan shutdown is disabled and fans run continuously. Repair or replace S2 to restore F0 fan control.

4. 04

   Monitor fan behavior relative to evaporator temperature

   Observe whether fans stop and start at the expected temperatures. Log evaporator temperatures alongside fan state to confirm F0 and F1 are operating as intended.

5. 05

   Adjust F0 if commissioning conditions have changed

   If cold room use or product type has changed requiring different evaporator operating temperatures, update F0 to match the new requirements. Document any changes in the commissioning record.

When to call a professional

Call a licensed refrigeration technician if adjusting F0 and F1 does not produce the expected fan behavior, or if the evaporator is consistently reaching temperatures outside the expected operating range regardless of fan control. Abnormal evaporator temperatures indicate a refrigerant system issue requiring professional diagnosis.