FCU 500, FCU 505 · Edition 02.17
121
Project planning information
14 .3 Electrical connection
The FCU is designed for connection to a 1-phase sys-
tem. All inputs and outputs have a one-phase mains
supply. Connected burner control units must use the
same phase of the mains supply.
The FCU is only to be used in grounded mains.
Wire the safety circuit inputs via relay contacts only.
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 FCU cables in the same cable duct as
frequency converter cables or cables emitting strong
fields.
Control lines must satisfy the requirements of
EN 60204-1, Chapter 12.
External electrical interference must be avoided.
14 .3 .1 OCU
Cables for signalling and telecommunications systems
are recommended for wiring the supplied plug connec-
tors:
Cable length max. 10 m, 4-pin,
min. 0.25 mm
2
(AWG 24),
max. 0.34 mm
2
(AWG 22).
