General Instruction; Flame Monitoring - Bentone BG 450 Installation And Maintenance Instructions Manual

GENERAL INSTRUCTION

Flame monitoring and measurement of ionisation current
The burner is monitored according to the ionisation principle. Check the
ionisation current on start-up and on each service call.
The reason for a low ionisation current may be leaking currents, bad
connection to earth, dirt or a faulty position of the flame electrode in the
burner head. Sometimes also a faulty gas/air mixture may cause too weak
a ionisation current.
The ionisation current is measured by means of a microampere meter (µA)
connected in series with the flame electrode and the gas burner control.
Connect the µA-meter, see figure. Min. required ionisation current accor-
ding to table. In practice this current must be considerably higher, prefe-
rably more than 10 µA. All the gas burners are equipped with a ionisation
cable that can be slit which facilitates the connection of the µA-device.
Gas control Connection to terminal
LME
LGB
LFL
MMI 810
TMG 740-3

Flame monitoring

in gas control
1
1
24
2
1
Min. ionisation
current required
5 µ A
10 µ A
10 µ A
5 µ A
5 µ A
172 305 25-1 12-01