Zener barriers - Operating instructions
How to select the correct barrier
7. The following points have to be clarified if special field devices
are used.
鈥?If the field device is a 4-20 mA transmitter: What load in
Ohms can be connected to the transmitter so that it can at-
tain 20 mA as before?
鈥?If the field device is a current / pressure converter: What
load can be connected to the controller card so that it can
attain 20 mA as before?
鈥?If the field device is a transmitter: How high is the load in
the safe area? (Typically, resistances of up to 250 Ohm are
used in the controller.).
NEW:
In the near future, a barrier will be available with a
replaceable back-up fuse.
The introduction of a replaceable back-up fuse ahead of the
integrated fuse provides protection against faults which could
occur during the commissioning of the system. It is always
arranged that the outer fuse will respond before the inner, inn-
accessible fuse. The fuses used are specially intended for use
on barriers.
Z...
Type
Channels
Max.
Series resist-
ance
Ohm
1
1
1
2
2
2
2
2
2
2
2
106
327
250
106
106
327
327
250
250
327
36 + 0.9V
250
25+ 0.9V
64
64
106
106
166
166
U
in
at 10 碌A(chǔ)
V
13
27
27
13
13
27
27
27
27
27
27
27
27
6.5
6.5
6.5
6.5
10
10
U
in
max
V
13.6
28
28
13.6
13.6
28
28
28
28
28
28
28
28
9.5
9.5
8.1
8.1
11.7
11.7
Fuse rating
External
fuse
mA
63
50
50
63
63
50
50
50
50
50
50
50
50
50
50
100
100
63
63
Fuse supplied
by
LITTLEFUSE
217,063
217,05
217,05
217,063
217,05
217,05
217,05
217,05
217.05
217.1
217.063
mA
100
80
80
100
100
80
80
80
80
80
80
80
80
80
80
160
160
100
100
Z715.F
Z728.F
Z728.H.F
Z765.F
Z779.F
Z779.H.F
Z787.F
Z787.H.F
Z960.F
Z961.F
Z966.F
Issue date
19.9.00
Subject to reasonable modifications due to technical advances.
Copyright Pepperl+Fuchs, Printed in Germany
Pepperl+Fuchs Group 鈥?Tel.: Germany (06 21) 7 76-0 鈥?USA (330) 4 25 35 55 鈥?Singapore 7 79 90 91 鈥?Internet http://www.pepperl-fuchs.com
447
1
2
3
4
5
6
