PFU 780 · Edition 02.12
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6 Project planning information
6 .1 Cable selection
Use mains cable suitable for the type of operation and com-
plying with local regulations. Do not route PFU cables in the
same cable duct as frequency converter cables or cables
emitting strong fields.
6 .1 .1 Ignition cable
Use unscreened high-voltage cable, see page 55 (Acces-
sories). Cable length: max. 5 m, recommended < 1 m. Screw
the ignition cable securely into the ignition transformer and
run to the burner by the shortest possible route.
The longer the ignition cable, the lower the ignition capacity.
Only use radio interference suppressed electrode adapters
(with 1 kΩ resistor) for ignition electrodes, see see page 55
(Accessories) . Do not lay UV/ionisation cable and ignition
cables together and lay them as far apart as possible.
6 .1 .2 Ionisation cable
Use unscreened high-voltage cable, see page 55 (Acces-
sories) . Cable length: max. 100 m. Avoid external electrical
interference. Install as far as possible from mains and igni-
tion cables and interference from electro-magnetic sources.
If possible, do not lay in a metal conduit. Several ionisation
cables can be routed together.
6 .1 .3 UV-Leitung
Cable length: max. 100 m. Avoid external electrical interference.
Install as far as possible from mains and ignition cables and
interference from electro-magnetic sources. If possible, do
not lay in a metal conduit. Several UV cables can be routed
together.
6 .2 Ignition electrode
6 .2 .1 Electrode gap
Gap between electrode and burner earth: 2 mm ± 0.5 mm.
6 .2 .2 Star electrodes
We recommend using 7.5 kV ignition transformers on burners
with star electrodes.