External fan fault

What does 24 mean?

This warning signifies that an external fan, monitored by the frequency converter's protective function, is not running or is not correctly mounted/detected. This indicates a potential cooling issue for external components or within the enclosure where the drive is installed, potentially leading to elevated operating temperatures. Similar to the internal fan, this monitor can be disabled via parameter 14-53 (Fan Monitor).

• External cooling fan motor failure (e.g., seized bearings, winding failure).
• Power supply issue to the external fan (e.g., loss of 400VAC or 230VAC auxiliary supply).
• External fan thermal switch tripped or faulty.
• Loss of fan feedback signal (e.g., tachometer signal, current sensing) to the frequency converter's monitoring input (e.g., terminals 27/29).
• Wiring fault (open circuit) between the external fan and the frequency converter's monitoring terminals.

Click steps to track your progress.

1. 1

   Power down the frequency converter and lockout/tagout. Visually inspect the external cooling fan blades for obstruction or damage.

2. 2

   Verify the auxiliary power supply voltage to the external fan terminals (e.g., L1F, L2F) is present and within specified range.

3. 3

   Check the status of any external fan thermal switches or overload relays (e.g., reset if tripped).

4. 4

   Measure the resistance across the external fan motor windings if accessible.

5. 5

   Inspect the wiring connection from the external fan feedback or monitoring circuit to the frequency converter's input terminals (e.g., 27, 29).

6. 6

   If the fan has a separate control, verify its operation independently from the drive.