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4 Design and Functions
4.2 Functional Description
Operating mode of the pilot burner
Fig. 4-5 Pilot burner versions A-B-C
DANGER!
High voltage on the bare ignition electrode!
Pilot burner is only permitted to be operated with correct earthing.
With version C in particular there is a danger of death when removing or omitting the earth-
ing; the housing earthing must be connected directly to the ignition transformer earthing!
In the event of damage to the earthing insulation, the device should be shut down; further
operation without repair is not permitted.
The ignition electrode is connected to the ignition transformer. The ignition transformer is sup-
plied from the system control.
The ionisation diode in the flame area of the pilot burner is connected to the flame scanner.
The flame scanner measures the ionisation current and evaluates it.
The amount of the ionisation current can also be determined via a shunt measuring principle
using a multimeter. The measured voltage is to be converted as follows into the ionisation cur-
rent: 10 mVDC = 1 ADC
When the flame is detected, the flame scanner activates the relay and the pilot light indicates
"flame on".
The system control detects the relay activity and implements this into system-specific actions.
WARNING!
Both analogue outputs have supply voltage reference!
Contact protection must be observed.
Measuring circuits must be safely separated from dangerous active components to
EN 61140 "Protection against electric shock".
Only use measurement and data interpreting devices that have double or reinforced insu-
lation.
1 Ignition electrode 3 Ionisation electrode 5 System control
2 Ignition transformer 4 Flame scanner
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General