Error detection signals of FM21 is detected continuously for a specified period of time while the ventilation assist fan/3 (FM21) is ON.
Measures to take when alert occurs:
- Jumper connector CN108
- Ventilation assist fan/3 (FM21)
- RU control board (RUCB)
- The message "Please call service" is displayed on the panel.
Solution:
- When HM- 102 is not connected, check if the jumper connector CN108 is connected. Connect the connector if its not connected.
- Check the connector connection and the wiring between RUCB and the fan, and repair it if any abnormality.
- Rotate the fan or I/O by hand, and repair it if any abnormality. (Wiring diagram: RU-509: 19-L).
- Replace FM21
- Replace RUCB.
