21
E
.0
4.
99
•
G
. 0
9.
05
.1
2
22. Flame control using ionization electrode
If an AC current is applied between the burner and the ionisation rod, a DC current flows due to the recti-
fying effect of the flame. This ionisation current forms the flame signal and is amplified and passed to con-
trol box. A flame cannot be faked because the rectifying effect no longer works if there is a short-circuit
between the sensor electrode and the burner.
23. Measuring the ionisation current
The ionisation current must be measured during burner start-up and maintenance or after a fault indication
in the control box. This done by disconnecting the plug in the ionisation cable and connecting it
to the ionisation measuring cable.
The measurement must be carried out directly after post-ignition during the safety time!
The ionisation current must be at least 1.5 µA. Values below 1.5 µA will result in unreliable operation or
produce a fault. In this case, clean the inside of the ionisation rod and the burner tube. Bend ionisation rod
if necessary. If the ionisation rod is defective, replace it. Check the cable for moisture and dry it if necessary.
24. Servicing the air pressure monitor
• Detach the silicone connecting hose and clean,
check the switching function.
• Replace the air pressure monitor if switching func-
tion is no longer working properly.
To do so:
• Switch off the burner voltage and disconnect
(7-pin connector X11.
• Unscrew the cover.
• Disconnect the electrical connectors.
• Release retaining screws on the housing.
• Reassemble in the reverse order..
"P1“ denotes the connecting point for the
pressure metering connection (silicone hose)!
P1
Service instructions/dimensions
Summary of Contents for GG20-LN
Page 29: ...29 E 04 99 G 09 05 12...
