BCU 580 · Edition 11.15
99
12 .3 Electrical connection
The BCU is designed for connection to a 1-phase system. All
inputs and outputs have a one-phase mains supply. Other
connected burner control units must use the same phase of
the mains supply.
The national standards and safety requirements must be satis-
fied. If the BCU is operated in ungrounded/IT systems, an insu-
lation monitoring device must be provided to isolate it from the
mains in the event of a fault. The cabling of the safety circuits
(e.g. pressure switches, gas valves) outside enclosed instal-
lation spaces must be protected from mechanical damage
and stress (e.g. vibration or bending) as well as short-circuits,
short-circuits to ground and cross-circuits.
Signal and control line for screw terminals max. 2.5 mm
2
(AWG 12), for spring force terminals max. 1.5 mm
2
(AWG 16).
Do not route BCU cables in the same cable duct as frequency
converter cables or cables emitting strong fields.
External electrical interference must be avoided.
12 .3 .1 OCU
Cables for signalling and telecommunications systems are
recommended for wiring the supplied plug connectors:
Cable length max. 10 m, 4-pin,
min. 0.25 mm
2
(AWG 24),
max. 0.34 mm
2
(AWG 22).
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