6
Operating Instructions
Safety Switch NZ.VZ-…VS
Correct use
Safety switches series NZ.VZ‑…VS are interlocking
devices with guard locking (with separate actuator)
for process protection without guard lock monitor‑
ing. The actuator has a low coding level. In combi‑
nation with a movable safety guard and the machine
control, this safety component prevents dangerous
machine functions from occurring while the safety
guard is open. A stop command is triggered if
the safety guard is opened during the dangerous
machine function.
This means:
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Starting commands that cause a dangerous ma‑
chine function must become active only when the
safety guard is closed.
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Opening the safety guard triggers a stop com‑
mand.
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Closing a safety guard must not cause automatic
starting of a dangerous machine function. A
separate start command must be issued. For
exceptions, refer to EN ISO 12100 or relevant
C‑standards.
Devices from this series are suitable only for process
protection.
Before the device is used, a risk assessment must
be performed on the machine, e.g. in accordance
with the following standards:
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EN ISO 13849‑1, Safety of machinery – Safety‑re‑
lated parts of control systems – Part 1: General
principles for design
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EN ISO 12100, Safety of machinery – General
principles for design – Risk assessment and risk
reduction
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IEC 62061, Safety of machinery – Functional
safety of safety‑related electrical, electronic and
programmable electronic control systems
Correct use includes observing the relevant require‑
ments for installation and operation, particularly
based on the following standards:
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EN ISO 13849‑1, Safety of machinery – Safety‑re‑
lated parts of control systems – Part 1: General
principles for design
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EN ISO 14119 (supersedes EN 1088), Safety of
machinery – Interlocking devices associated with
guards – Principles for design and selection
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EN 60204‑1, Safety of machinery – Electrical
equipment of machines – Part 1: General re‑
quirements
Important!
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The user is responsible for the proper integration
of the device into a safe overall system. For this
purpose, the overall system must be validated,
e.g. in accordance with EN ISO 13849‑2.
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If the simplified method according to section 6.3
of EN ISO 13849‑1:2008 is used for determining
the Performance Level (PL), the PL might be re‑
duced if several devices are connected in series.
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Logical series connection of safe contacts is
possible up to PL d in certain circumstances.
More information about this is available in
ISO TR 24119.
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If a product data sheet is included with the prod‑
uct, the information on the data sheet applies
in case of discrepancies with the operating
instructions.
Safety precautions
WARNING
Danger to life due to improper installation or due
to bypassing (tampering). Safety components
perform a personal protection function.
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Safety components must not be bypassed,
turned away, removed or otherwise rendered
ineffective. On this topic pay attention in partic‑
ular to the measures for reducing the possibility
of bypassing according to EN ISO 14119:2013,
section 7.
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The switching operation must be triggered only
by actuators designated for this purpose.
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Prevent bypassing by means of replacement
actuators. For this purpose, restrict access to
actuators and to keys for releases, for example.
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Mounting, electrical connection and setup only
by authorized personnel possessing special
knowledge about handling safety components.
CAUTION
Danger due to high housing temperature.
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Protect switch against touching by personnel or
contact with inflammable material.
Function
The safety switch permits the locking of movable
safety guards for process protection.
The switch contains a rotating cam disk and a lock‑
ing arm that block/release the guard locking pin.
The guard locking pin is moved on the insertion/
removal of the actuator and on the activation/
release of the guard locking. During this process
the switching contacts are actuated.
If the guard locking pin is blocked (guard locking
active), the actuator cannot be pulled out of the
switch head. For design reasons, guard locking can
be activated only when the safety guard is closed
(failsafe locking mechanism).
The safety switch is designed so that fault ex‑
clusions for internal faults in accordance with
EN ISO 13849‑2:2013, Table A4, can be assumed.
Version VSM
(guard locking actuated by spring force and released
by energy ON)
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Activating guard locking: close safety guard; no
voltage at the solenoid
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Releasing guard locking: apply voltage to the
solenoid
The spring‑operated guard locking functions in
accordance with the closed‑circuit current princi‑
ple. If voltage is interrupted at the solenoid, guard
locking remains active and the safety guard cannot
be opened directly.
If the safety guard is open when the power supply
is interrupted and the guard is then closed, guard
locking is activated. This can lead to persons being
locked in unintentionally.
Figure 1: Locking method VSM
Version VSH
(guard locking actuated by spring force and released
by manual release)
Important!
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This type may be used only in special cases after
strict assessment of the accident risk!
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The safety guard can be opened imme‑
diately on pressing the manual release!
The guard locking is held in position by spring force
and released by pressing the manual release. The
guard locking is independent of the power supply.
Version VSE
(guard locking actuated by energy ON and released
by spring force)
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Activating guard locking: apply voltage to the
solenoid
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Releasing guard locking: disconnect voltage from
the solenoid
The magnetically actuated guard locking operates in
accordance with the open‑circuit current principle. If
the voltage at the solenoid is interrupted, the guard
locking is released and the safety guard can be
opened directly!
Figure 2: Locking method VSE
Switching states
The detailed switching states for your switch can be
found in Figure 4. All available switching elements
are described there.
Safety guard open
VSM, VSH and VSE:
The safety contacts are open.
Safety guard closed and not locked
VSM, VSH and VSE:
The safety contacts are closed.
Safety guard closed and locked
VSM, VSH and VSE:
The safety contacts are closed.
Selection of the actuator
NOTICE
Damage to the device due to unsuitable actuator.
Make sure to select the correct actuator.
Additionally pay attention to the door radius and
the fastening options (see Figure 10).
Manual release
Some situations require guard locking to be released
manually (e.g. malfunctions or an emergency). A
function test should be performed after release.
More information on this topic can be found in the
standard EN ISO 14119:2013, section 5.7.5.1. The
device can feature the following release functions:
Manual release with automatic
return
Permits opening of a locked safety guard from
outside the danger area without tools.
Important!
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It must be possible to operate the manual re‑
lease manually from outside the protected area
without tools.
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The manual release must possess a marking indi‑
cating that it may be used only in an emergency.
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The actuator must not be under tensile stress
during manual release.
Actuating the manual release does not affect the
switching contacts.
