Ferroli OMNIA M 3.2 Installation And Owner's Manual page 129

9.3.5 Controls parts for backup heater(Optional)
4 2
3 1
1-phase 8-16kW with backup heater(1-phase 3kW)
3-phase 12-16kW with backup heater(1-phase 3kW)
Coding Assembly unit
Auto thermal protector
1
2 Manu thermal protector
Backup heater contactor KM1
3
4 3
1-phase 4/6kW with backup heater(1-phase 3kW)
30
2
1
3 4 2 1
1-phase 8-16kW with backup heater(3-phase 9kW)
3-phase 12-16kW with backup heater(3-phase 9kW)
Coding Assembly unit
Backup heater contactor KM2
4
5 Backup heater contactor KM3
5