VEGA Z728 Zener barriers - Manual (Page 4)

4
Zener barriers - operating instructions
Installation notes
Subject to reasonable modifications due to technical advances. Copyright Pepperl+Fuchs, Printed in Germany
Pepperl+Fuchs Group • Tel.: Germany +49 621 776-0 • USA +1 330 4253555 • Singapore +65 67799091 • Internet http://www.pepperl-fuchs.com
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1.4 Installation notes
Pepperl+Fuchs Zener barriers in the Z7, Z8 and Z9 series can
be mounted on a standard rail to EN 50022 in 3 different
arrangements.
• Equipotential bonding via the standard rail (grounding of all
snapped-on Zener barriers)
• Group grounding through insulated mounting
• Individual grounding through insulated mounting
Pepperl+Fuchs Zener barriers also feature a space-saving
12.5 mm housing which incorporates up to 3 channels.
Figure 1.11 Mechanical features
Construction: Modular terminal housing in Makrolon,
flammability classification UL 94: V -0
Fixing: Snaps onto 35 mm standard rail to DIN EN 50022
Connection options: Self-opening terminals, max. core cross-
section 2 x 2.5 mm²
The barriers are usually installed in racks or control cabinets.
They can be built into housings under production conditions,
with the proviso that the housing must afford adequate
protection. They can also be employed in hazardous areas,
when it has been ascertained that the housing has been
certificated for this purpose.
The installation must be carried out in such a way that the
intrinsic safety is not compromised by the following factors:
• Danger of mechanical damage
• Non-authorised changes or influence exerted by external
personnel
• Humidity, dust or foreign bodies
• Ambient temperature exceeding the permissible level
• The connection of non-intrinsically safe circuits to
intrinsically safe circuits
Grounding of the mounting rail is of the normal type, i. e. both
ends are connected to the intrinsically safe ground. This also
simplifies checking the grounding.
Many installations provide the option of subsequent expansion.
Replacement cable for this purpose can be connected to the
Z799 dummy barrier and unused cable can be connected to
the intrinsically safe ground.
Figure 1.8 Equipotential bonding via the standard rail
Insertion strip
ZH-ES/LB
Clamp
ZH-Z.USLKG5
Label carrier
ZH-Z.BT
DIN rail NS 35/7.5
35 mm standard rail
to DIN EN 50 022
Mounting block
ZH-Z.AB / NS
Figure 1.9 Insulated mounting (Individual grounding)
Single socket
ZH-Z.ES
Connector for
ground lead
ZH-Z.AK4
Connector
ZH-Z.AK16
Mounting block
ZH-Z.AB/SS
Ground rail feed
ZH-Z.LL
N-Combined rail
ZH-Z.NLS-Cu3/10
Spacing roller
ZH-Z.AR.125
Figure 1.10 Insulated mounting (Individual grounding)
110 12.5
115