EUCHNER TZxxx - Manual (Page 5)

Operating Instructions TZ... Safety Switch
Correct use
Safety switches series TZ are interlocking devices with
guard locking.
In combination with a 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 guard is 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.
In applications for the protection of people, the position
of the guard locking must be monitored by evaluating
the contact for the solenoid monitoring in the safety
circuit.
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 60 204-1, Electrical equipment of machines
Important:
f The user is responsible for the 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
from EN 1088:1995+A2:2008, section 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
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.
Position monitoring of the safety guard and guard lock
monitoring are performed via two separate switching
elements.
Version TZ1 (guard locking by spring force)
The guard locking is held in position by a spring loaded
pin attached to a solenoid. The guard locking is released
when voltage is applied to the solenoid. The 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 TZ2 (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 is held in the locked position by an
electromagnetically actuated pin and released by sp-
ring 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
actuator into the safety switch.
TZ1: The guard locking pin is moved to locked position
by spring force.
Door safety circuit SK and monitoring circuit ÜK are
closed.
Only the green LED is illuminated
1) .
TZ2: The safety circuit SK is closed, the red and the
green LEDs are illuminated
1) .
The guard locking pin is moved to locked position when
the solenoid operating voltage is applied.
The monitoring circuit ÜK is closed.
Only the green LED is illuminated
1) .
f Deactivating guard locking, opening safety guard
TZ1: The guard locking pin releases the cam when
the solenoid operating voltage is applied.
The monitoring circuit ÜK is opened.
The red and the green LEDs are illuminated
1) .
The actuator can be removed.
Safety circuit SK is positively opened and blocked in
this position when the actuator is removed. This signals
that the safety guard is open.
Only the red LED is illuminated
1) .
TZ2: The guard locking pin releases the cam when
the solenoid operating voltage is switched off.
The monitoring circuit UK is opened.
The red and the green LEDs are illuminated
1) .
The actuator can be removed.
Safety circuit SK is positively opened and blocked in
this position when the actuator is removed. This signals
that the safety guard is open.
Only the red LED is illuminated
1) .
Mechanical release
In the event of malfunctions, the guard locking can be
deactivated using the mechanical release, irrespective
of the state of the solenoid (see Figure 3).
f Remove key from sealing wire.
f Remove locking screw.
f Release by turning the key.
f The safety device can be opened.
1) The LED function is described in these operating instructions based on version TZ...SR6 with standard wiring (see Figure 2a: pin 1 = ࿜ / pin 5 = ࿛ / pin 2, 3, 6 to the PLC).
f Attach mechanical release again in the reverse order.
The seal must be restored after use by fitting a new
sealing wire.
Mounting
The switch must be protected against contact with
inflammable material or accidental touching.
Safety switches and actuators must not be used as
an end stop.
Mount the safety switch only in assembled condition!
Assemble the safety switch so that
f access to the switch is difficult for operating personnel
when the safety guard is open
f operation of the mechanical release is still possible
f inspection and replacement by authorized personnel
is possible.
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.
f Fit an additional stop for the movable part of the safety
guard.
Changing the actuating direction
Fig. 1: Changing the actuating direction
f Insert the actuator in the actuating head.
f Remove the screws from the actuating head.
f Set the required direction.
f Tighten the screws with a torque of 1.2 Nm.
Protection against environmental influences
A lasting and correct safety function requires that the
actuating head must be protected against the penetration
of foreign bodies such as swarf, sand, blasting shot etc.
Cover the actuating slot, the actuator and the rating plate
during painting work!
Electrical connection
When choosing the insulation material and wire for
the connections, attention is to be paid to the over-
temperature in the housing (depending on the
operating conditions).
For TZ without plug connector:
For use and applications as per the requirements of
, a rigid copper wire 60/75° is to be used.
For TZ..024 with plug connector:
For use and applications as per the requirements of
, a class 2 power supply or a class 2 transformer
according to UL1310 or UL1585 must be used.
Connection cables for safety switches installed at the
place of use must be separated from all moving and
permanently installed cables and un-insulated active
elements of other parts of the system which operate at
a voltage of over 150 V. A constant clearance of 50.8
mm must be maintained. This does not apply if the
moving cables are equipped with suitable insulation
materials which possess an identical or higher dielectric
strength compared to the other relevant parts of the
system.
The operating voltage for the guard locking solenoid must
match the value on the rating plate (e.g. U
S
= AC/DC 24 V).
SK ÜK
1 2 3 4 5 6
GN RD
Safety guard closed, actuator
locked
Solenoid
➀ ➁
➂