FCU 500, FCU 505 · Edition 02.17
122
Project planning information
14 .3 .2 Safety current inputs
Actuation of the safety current inputs only with switch-
gear featuring mechanical contacts. If switchgear with
semi-conductor contacts is used, the safety current
inputs must be connected using relay contacts.
To safeguard the safety current inputs, the fuse must be
designed so that the sensor with the lowest switching
capacity is protected.
The cabling outside enclosed installation 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.
1
2
3
46
47
48
49
50
4
67
52
45
51
65
66
68
41
42
16
17
18
57
13
14
15
53
54
55
56
62 61
5 6 7 8
11 12
N
P
HT
ϑ
0 V
L1
V1
V2
V3
LDS
FCU 505
+ - + -
K2
K1
k11 k21
3,15AT
µC
24V
DC
88
M
+24 V
PZL
PDZ
PZL
PZH
P70
P71
P73
P72
P69
PZL
PDZ
PZL
PZH
P70
P71
P73
P72
p
u
2
GZL
PZL
58
5AT
44
FCU 500
Air
min
Air
STM/
STL
Gas
max
Gas
min
0.6 × I
N
I
N
× 0.6
Calculation
I
N
= current of the sensor/contactor with the lowest
switching capacity
Suitable fuse = 0.6 × I
N