EUCHNER STP-TWxxx (Twin) - Manual (Page 4)

Operating Instructions Safety Switch STP-TW... (Twin)
Correct Use
Safety switches series STP-TW... (Twin) are
electromagnetic interlock devices with guard locking.
In combination with a separating safety guard and
the machine control, this safety component prevents
the safety guard from being opened while a dangerous
machine movement is being performed.
For the control system, this means that
f starting commands which cause hazardous
situations must become active only when the safety
guards are in protective position and the guard
locking is in locked position.
The locked position of the guard locking must be
released only when the hazardous situation is no
longer present.
Before safety switches are used, a risk assessment
must be performed on the machine in accordance
with
f EN ISO 13849-1, Safety of machinery. Safety related
parts of control systems. General principles for
design
f EN ISO 14121, Safety of machinery. Risk
assessment. Principles
f IEC 62061, Safety of machinery – Functional safety
of safety-related electrical, electronic and
programmable electronic control systems.
Correct use includes compliance with the relevant
requirements for installation and operation, particularly
f EN ISO 13849-1, Safety of machinery. Safety related
parts of control systems. General principles for
design
f EN 1088, Safety of machinery. Interlocking devices
associated with guards. Principles for design and
selection
f EN 60204-1, electrical equipment of machines
Important:
f The user is responsible for safe integration of the
device in a safe overall system. For this purpose
the overall system must be validated, e.g. in
accordance with EN ISO 13849-2.
f If the simplified method according to section 6.3
EN ISO 13849-1:2008 is used for validation, the
Performance Level (PL) may be reduced if several
devices are connected one after the other.
f If a product data sheet is included with the product,
the information on the data sheet applies in case of
discrepancies with the operating instructions.
Safety Precautions
Safety switches fulfill a personal protection function.
Incorrect installation or tampering can lead to severe
injuries to personnel.
Safety components must not be bypassed
(bridging of contacts), turned away, removed or
otherwise rendered ineffective.
On this topic pay attention in particular to the
measures for reducing the possibility of bypassing
according to EN 1088:1995.A2:2008, sec. 5.7.
The switching operation may only be triggered
by actuators specially provided for this purpose
which are permanently connected to the
protective guard.
Mounting, electrical connection and setup only
by authorized personnel.
Function
Safety switches series STP-TW... (Twin) have two
actuator heads. They permit the simultaneous locking
or unlocking of two movable safety guards. Both
actuators must be inserted in order to activate guard
locking.
The safety switch permits the locking of movable
safety 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 / deactivation of the
guard locking. During this process the switching
contacts are actuated.
If the cam is blocked, the actuator cannot be pulled
out of the switch head
¨ guard locking active.
Actuator Version
Actuator S for safety switches STP-TW... without
insertion funnel.
Actuator L for safety switches STP-TW... with insertion
funnel.
Version STP-TW3...
(Guard locking by spring force)
The guard locking pin is held in the locked position by
spring force and released by electromagnetic
actuation. The spring interlock guard locking functions
in accordance with the closed-circuit current principle.
The safety guard cannot be opened immediately in
the event of interruption of the solenoid power supply.
Version STP-TW4...
(Guard locking by solenoid force)
This type must be used only in special cases
after strict assessment of the accident risk!
The safety guard can be opened immediately in
the event of interruption of the solenoid power
supply!
The guard locking pin is held in the locked position by
electromagnetic force and released by spring force.
The guard locking operates in accordance with the
open-circuit current principle.
f Closing safety guard and activating guard locking
The guard locking pin is released by insertion of the
two actuators into the safety switch.
STP-TW3...: The guard locking pin is moved to locked
position by spring force.
STP-TW4...: The guard locking pin is moved to locked
position when the solenoid operating voltage is
applied.
The safety contacts are closed.
f Deactivating guard locking, opening safety guard
STP-TW3... (with door monitoring contact): The guard
locking pin releases the cam when the solenoid
operating voltage is applied.
For switching function see Figure 3 column 2 Door
closed and not locked
The actuator can be removed.
On the removal of the actuator, the door monitoring
contact switches and signals that the safety guard is
open (see Figure 3 column 3,
Door open).
STP-TW4... (with door monitoring contact): The guard
locking pin releases the cam when the solenoid
operating voltage is switched off.
For switching function see Figure 3 column 2 Door
closed and not locked
The actuator can be removed.
On the removal of the actuator, the door monitoring
contact switches and signals that the safety guard is
open (see Figure 3 column 3,
Door open).
Mechanical Release
In the event of malfunctions, the guard locking can
be released with the mechanical release irrespective
of the state of the solenoid (see Figure 4).
If the switch has a mechanical key release (optional),
the guard locking can be retained in the „not locked“
position (see Figure 1). Accidental locking in, for
example, of maintenance personnel is then prevented.
f Actuating mechanical release
1. Unscrew locking screw.
2. Using a screwdriver, turn the mechanical release
by around 180° in the direction of the arrow
3. Return the locking screw to its original position
and seal after use (for example with sealing
lacquer or using wire).
f Actuating mechanical key release
1. Insert key in the key opening
2. Rotate key from pos.1 (normal operation) to pos.2
(locked)
3. Remove key
4. Return to original position after use
Indication
The position of the guard locking is indicated in the
window.
Figure 1: Mechanical key release and display
Installation
Safety switches and actuators must not be used
as an end stop.
Mount the safety switch only in assembled
condition!
To achieve the stated locking force, the mounting
holes on the switch head must also be used (see
figure 4).
Caution! Risk of burns due to high surface
temperature at ambient temperatures above 40
°C! Protect switch against touching by personnel
or contact with inflammable material.
Assemble the safety switch so that
f access to the switch is difficult for operating
personnel when the safety guard is open.
f it is possible to operate the mechanical release and
check and replace the safety switch.
f the escape release can be actuated from the hazard
area.
Fit an additional end stop for the movable part of the
safety guard.
f Insert the actuator in the actuating head.
f Mount the safety switch positively.
f Permanently connect the actuator to the safety
guard so that it cannot be detached, e.g. using the
enclosed non-removable screws, rivets or welding.
Changing the Actuating Direction
Figure 2: Changing the actuating direction
f Remove the screws from the actuating head.
f Set the required direction.
f Correct arrangement of the screws (see figure 2).
f Tighten the screws with a torque of 0.6 Nm.
f Cover the unused actuating slots with the enclosed
slot covers.
Marking
Locked
Not locked
Pos. 2
(locked)
Pos. 1
(normal
operation)