5
Operating Instructions
Safety Switch STP-BI…
Correct use
Safety switches series STP‑BI are interlocking devic‑
es with guard locking solenoid (separate actuator).
The actuator has a low coding level. In combination
with a movable guard and the machine control, this
safety component prevents the guard from being
opened while a dangerous machine function is
being performed.
This means:
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Starting commands that cause a dangerous ma‑
chine function must become active only when the
guard is closed and locked.
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The guard locking device must not be unlocked
until the dangerous machine function has ended.
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Closing and locking a guard must not cause auto‑
matic 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 also suitable 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, 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.
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 13849‑1:2015 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.
The STP‑BI has an additional function intended to
prevent
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persons from unintentionally locking themselves
inside if the safety door is open in case of a power
failure or if the machine is switched off
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the deactivation of the activated guard locking in
case of a power failure.
Important!
This additional function is not a safety function!
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 at ambi‑
ent temperatures above 40 °C.
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Protect switch against touching by personnel or
contact with inflammable material.
Description of the safety function
Devices from this series feature the following safety
functions:
Monitoring of guard locking and the position
of the guard (interlocking device with guard
locking according to EN ISO 14119)
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Safety function (see “Function” chapter):
‑ The guard lock monitoring switching contacts are
open when guard locking is released (monitoring
of the locking device).
‑ The safety contacts are open when the guard
is open.
‑ Guard locking can be activated only when the
actuator is located in the switch head (failsafe
locking mechanism).
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Safety characteristics: B
10D
(see “Technical data”
chapter).
Activation of guard locking
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Safety function
If the device is used as guard locking for person‑
nel protection, control of guard locking must be
regarded as a safety function.
The safety level of guard locking control is deter‑
mined by the device (PFH
D
int.
) and by the external
control (e.g. PFH
D
ext.
of the standstill monitor).
PFHD
ext.
PFHD
int.
(internal electronic)
Guardlocking Device
(e.g. standstill
monitor)
(locking mean)
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Safety characteristics: category, Performance
Level, PFH
D
(see “Technical data” chapter ).
Function
The safety switch permits the locking of movable
guards.
In the switch head there is a rotating cam that is
blocked/released by 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 cam is blocked (guard locking active), the
actuator cannot be pulled out of the switch head.
For design reasons, guard locking can be activat‑
ed only when the 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.
The switch has – in addition to mechanical guard
locking – fixing for the guard locking pin. The guard
locking pin is held in its current position if the operat‑
ing voltage is not present. The guard locking pin can
be moved only by applying the operating voltage.
In case of interruption of the power supply (operating
v control voltage) for the switch or if the
machine is switched off for servicing, for example,
the guard locking pin is held in its last position. As
a result the safety door is either permanently locked
or it can be closed and opened as often as required
without the guard locking pin locking.
Position monitoring of the guard and guard lock
monitoring are performed via the same switching
element.
Guard lock monitoring
All versions feature at least one safe contact for
monitoring guard locking. The contacts are
opened when guard locking is released.
Activation of guard locking
The safety contacts are opened if the guard locking
control electronics should fail.
Safety characteristics: see “Technical data”
Door monitoring contact
Version STP3 additionally features at least one door
monitoring contact. Depending on the switching
element, the door monitoring contacts can be
either positively driven (contacts ) or not posi‑
tively driven.
The door monitoring contacts are actuated when
the guard is opened.
Version STP3-BI
(Guard locking actuated by control voltage OFF and
released by control voltage ON)
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Activating guard locking: close the guard, apply
operating voltage
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Releasing guard locking: apply operating and
control voltage
Switching states
The detailed switching states for your switch can be
found in Figure 2. All available switching elements
are described there.
Guard open
STP3‑BI:
The safety contacts and are open.
Guard closed and not locked
STP3‑BI:
The safety contacts are closed. The safety
contacts are open.
Guard closed and locked
STP3‑BI:
The safety contacts and are closed.
