GB-4
Cable selection
▷Signal and control line for screw terminals max.
2.5mm2(min.AWG24, max.AWG12), for spring
force terminals max. 1.5mm
2
(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.
▷Avoid external electrical interference.
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 unit features an output for fan control (termi-
nal58). This single-pole contact can be loaded
with a max. of 3A. The max. start-up current of
the fan motor must not exceed a value of max.
6A for 1s– use an external motor protection
or coupling contactor if required.
▷
The limiters in the safety interlock (linking of all the
relevant safety control and switching equipment
for the use of the application, for example, safety
temperature limiter) must isolate terminal46 from
the voltage supply. If the safety interlock is in-
terrupted, the display shows a blinking
50
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).
Adjust the minimum pause time tBP (param-
eter62) 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 page19 (Parameters and values).
Disconnect the system from the electrical power
supply.
Before wiring the BCU, ensure that the yellow
parameter chip card has been inserted in the
BCU – see page 3 (Replacing the power
module/parameter chip card).
▷
Screw terminals or spring force terminals are
available for the BCU– see page23 (Acces-
sories).
Wire as shown on the connection diagram– see
page5 (Connection diagram).
▷Ensure a good PE (ground) wire connection to
the BCU and burners.
