Page 18
UNIT HEATER
2.5 Thermocouple Interrupter Relay
All manual ignition heaters are fitted with a thermocouple interrupter relay to interface between the
limit thermostats and the thermocouple. This relay is fully encapsulated and if faulty must be replaced
with the same type as it is specially produced to operate with burner thermocouples.
For normal operation the limit thermostats provide a constant voltage to the coil connections making
the relay permanently energised unless the limit thermostats operate or the electrical supply is interrupted.
In the event of interruption of the electrical supply to the interrupter relay then the contact opens and
the safety valve of the multifunctional gas valve closes. The pilot will then need to be manually relit.
2.6 Automatic Ignition - Burner Control Box
2.6.1 DESCRIPTION OF SATRONIC TFI 812 2B Mod 10 CONTROL BOX
The fully automatic gas burner fitted to all CUHA/A, CUHB/A, CUHC/A and CUHD/A models is
controlled by a Satronic TFI 812 2B Mod 10 plug-in control box. This control ensures the safe start
and stop sequence and also monitors the safe presence of a flame.
Fig 2.9 Satronic TFI 812 Control Box Sequence
To Next Page
Loading...
