Technical information

IFD 244 · Edition 03.08
26
Project planning information
Wiring7.10
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.
Note on EC type-examination7.11
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.
Installation of solenoid valves for gas7.12
During the safety time on start-up tSA, 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.
Flame control7.13
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.
Flame signal cut-off point7.14
The automatic burner control unit IFD is set to 2 μA at the
factory.