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PFU 780 · Edition 02.12l
50
Project planning information
6 Project planning information
6 .1 Cable selection
Use mains cable suitable for the type of operation and
complying 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 56
(Accessories). 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 pos-
sible route.
The longer the ignition cable, the lower the ignition
capacity. Only use radio interference suppressed elec-
trode adapters (with 1 k
Ω
resistor) for ignition elec-
trodes, see see page 56 (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 56
(Accessories) . Cable length: max. 100 m. Avoid ex-
ternal 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 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. Sev-
eral 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.