GB-4
Cable selection
▷Signal and control line for screw terminals max.
2.5mm2(min.AWG24, max.AWG12), for spring
force terminals max. 1.5mm2(min.AWG24,
max.AWG12).
▷
Do not route BCU cables in the same cable duct
as frequency converter cables or cables emitting
strong fields.
▷
The control lines must be selected in accordance
with local/national regulations.
▷
External electrical interference must be avoided.
Ionization cable, UVcable
▷Cable lengths of 100m are acceptable if there
is no electromagnetic interference.
▷
The flame signal is adversely affected by EMCin-
fluences.
▷
Lay cables individually (with low capacitance)
and, if possible, not in a metal conduit.
Wiring
▷
Do not reverse phaseL1 and neutral conduc-
torN.
▷
Do not connect different phases of a three-phase
current system to the inputs.
▷Do not supply voltage to the outputs.
▷A short-circuit on the outputs causes one of the
replaceable fuses to trip.
▷Do not set the remote reset so that it operates
(automatically) in cycles.
▷Wire the safety circuit inputs via contacts (relay
contacts) only.
▷
The limiters in the safety interlock (e.g. safety
temperature limiter, emergency stop) must iso-
late terminal 46, as well as the optional safety-
relevant inputs at terminals 65 to 68 if these are
parameterized, from the voltage supply. If the
safety interlock is interrupted, the display shows
a blinking 51 as a warning signal and all of the
BCU’s control outputs are disconnected from
the electrical power supply.
▷Connected control elements must be equipped
with protective circuits in accordance with the
manufacturer’s instructions. The protective circuit
prevents high voltage peaks which can cause
malfunctioning of the BCU.
▷
Observe the maximum duty cycle for the ignition
transformer (see manufacturer’s instructions). Ad-
just the minimum pause timetBP (parameter62)
correspondingly, if required.
▷
Functions of terminals 51, 65, 66, 67 and 68 are
dependent on parameter values:
Terminal Dependent on parameter
51 69
65 70
66 71
67 72
68 73
See page23 (Parameters and values).
1 Disconnect the system from the electrical power
supply.
Before wiring, ensure that the yellow parameter
chip card has been inserted in the BCU– see
page 3 (Replacing the power module/pa-
rameter chip card).
▷
Screw terminals or spring force terminals are
available for the BCU– see page27 (Acces-
sories).
Wire as shown on the connection diagram– see
page5 (Connection diagram) onwards.
▷Ensure a good PE (ground) wire connection to
the BCU and burners.
▷
To safeguard the safety current inputs (terminals
45 to52 and 65to68), the fuse must be de-
signed so that the sensor with the lowest switch-
ing capacity is protected.
