IFD 258 · Edition 10.09
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Project planning information
7 .10 Wiring
The IFD is suitable for hard wiring only. Do not reverse phase
and neutral conductor. Different phases of a three-phase
current system must not be installed at the IFD.
No voltage may be connected to the valve and ignition out-
puts.
Do not use unused terminals as support terminals.
The signalling contacts for operating and fault signals do
not meet the requirements for safety extra low voltage (SELV/
PELV).
The burner should be adequately earthed. Incorrect wiring
and an insufficient earth connection can cause damage to
the equipment during single-electrode operation.
In the case of single-electrode operation, only ignition trans-
formers of type TZI or TGI may be used. The use of pulse-spark
or high-frequency ignition devices is not permitted.
7 .11 Note on EC type-examination
Since EN 298 (1993) does not describe all functions of the IFD,
the operator is responsible for ensuring that all parameters
and functions are matched to the respective application.
7 .12 Installation of solenoid valves for gas
During the safety time on start-up t
SA
, the burner must be
supplied with gas and ignited. For this reason, the gas so-
lenoid valve should be installed as close as possible to the
burner itself.
7 .13 Flame control
7 .13 .1 With ionisation sensor
The IFD generates an alternating voltage (230 V AC) between
the sensing electrode and burner earth. The flame rectifies
this voltage. Only the DC signal (> 2 µA) is recognised by the
automatic burner control unit as a flame.
A flame cannot be simulated by a short-circuit.
Ignition and monitoring with a single electrode are possible,
see [Connection diagrams – p. 10].
7 .13 .2 With UV sensor UVS
A UV tube inside the UV sensor detects the ultraviolet light of
a flame. It does not respond to sunlight, incandescent bulb
light or infrared radiation emitted by hot workpieces or red-
hot furnace walls.
In the event of incident UV radiation the UV sensor rectifies
the supplied alternating voltage. As with ionisation control, the
automatic burner control unit only detects this DC signal.
In the case of flame control with the UV sensor UVS, only
intermittent operation is allowed (a flame simulation check
must be carried out once every 24 hours).
7 .14 Flame signal cut-off point
The cut-off point can be set between 2 and 20 µA using a po-
tentiometer in the upper section of the housing. The automatic
burner control unit IFD is set to 2 µA at the factory.
If a flame is detected during the burner start,
01
flashes on
the display to indicate a fault.
