4
Operating Instructions
Enabling Switch ZXE
Correct use
The enabling switches described are manually
actuated command switches that make it possi‑
ble to work in the danger zone of machines and
installations.
Enabling switches represent part of a safety‑related
control system according to EN ISO 13849‑1 or
EN 62061 and fulfill a safety function. In conjunction
with other safety functions, e.g.
SLS = Safely Limited
Speed according to EN 61800‑5‑2
, the enabling
switches can be used as part of an enabling system
according to EN ISO 12100 for working with open
guards or switched‑off safety guards. The various
safety guards must be activated via a control or
operating mode selector that can be locked in every
position or via an equivalent device.
The device possesses a three‑position enabling
switch according to EN 60947‑5‑8 or is a device
for enabling control with three positions according
to EN 60204‑1. A dangerous movement is only
allowed to be enabled in position 2 (center position).
Authorized operating personnel can then enter the
danger zone, e.g.:
f
for setting up
f
for observing work sequences
f
for maintenance.
Before the device is used, a risk assessment must
be performed on the machine, e.g. in accordance
with the following standards:
f
EN ISO 13849‑1
f
EN ISO 12100
f
IEC 62061
Correct use includes observing the relevant require‑
ments for installation and operation, particularly
based on the following standards:
f
EN ISO 13849‑1
f
EN 60204‑1
f
IEC 62061
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
The enabling switch user must assess and
document remaining risks.
f
If a data sheet is included with the product, the
information on the data sheet applies.
Description of the safety function
If dual‑channel evaluation of the enabling switch
is used with monitoring for same contact state
or antivalent contact state, category 3 as per
EN ISO 13849‑1 is achieved.
Devices from this series feature the following safety
function:
Enable control
(manually activated interlocking function in a
control system according to EN 60204‑1)
Safety function:
f
If the enabling switch is not pressed (position 1),
at least one of the contacts is open.
f
If the enabling switch is pressed all the way down
(position 3), at least one of the contacts is open.
Safety characteristic:
f
B
10D
(see section
Technical data
).
Exclusion of liability and warranty
In case of failure to comply with the conditions for
correct use stated above, or if the safety regula‑
tions are not followed, or if any servicing is not
performed as required, liability will be excluded and
the warranty void.
General safety precautions
Enabling switches fulfill personnel protection func‑
tions. Incorrect installation or tampering can lead to
fatal injuries to personnel.
Check the safe function of the guard particularly
f
after any setup work
f
after the replacement of a system component
f
after an extended period without use
f
after every fault.
Independent of these checks, the safe function of
the guard should be checked at suitable intervals
as part of the maintenance schedule.
f
No commands for potentially hazardous conditions
are allowed to be initiated with enabling switches
alone.
f
The safety function of enabling switches must not
be bypassed (bridging of contacts), tampered with
or otherwise rendered ineffective.
f
The enabling switch must be protected against
tampering by the operator.
f
Enabling switches may be used only by autho‑
rized persons who can recognize hazards in
time and who are able to take appropriate action
immediately.
f
Every person present in the danger zone must car‑
ry his/her own enabling switch on his/her person.
f
Mounting, electrical connection and setup only by
authorized personnel.
In the event of malfunctions or damage, the en‑
abling switch must be replaced. The device may be
repaired only by the manufacturer.
Important!
Prior to use, read the operating instructions and
keep these in a safe place. Ensure the operating
instructions are always available during mount‑
ing, setup and servicing. You should archive a
printed copy of the operating instructions. You
can download the operating instructions from
www.euchner.com.
Function
Enabling switches are used as a manual interlocking
device for a control system (enable control). In posi‑
tion 2, the enabling switch permits machine opera‑
tion with a separate start control. In position 1 and
in position 3, a stop function must be initiated by the
machine control and machine operation prevented.
f
Position 1: Off function, pushbutton not pressed
f
Position 2: Enabling function (ON), pushbutton
pressed to center position (actuating
point)
f
Position 3: Off function, pushbutton pressed to
end stop
The enabling function is canceled by releasing the
pushbutton or pressing it beyond the actuating
point. The enabling function does not reactivate as
it passes position 2 while returning from position 3
to position 1.
With versions ZXE‑104833, ZXE‑111276 and
ZXE‑120348, a click sounds during the change from
position 1 to position 2 and during the return from
position 2 to position 1.
Mounting
Important!
The enabling switch must be fitted in a suitable
housing.
f
Screw the knurled nut on the enabling switch
down as far as possible and slide enabling switch
without protective cap through the front panel
cut‑out from the rear.
f
Screw protective cap onto the front of the enabling
switch to the end stop.
f
Screw the knurled nut against the control panel
and tighten.
f
During installation it must be ensured that all three
switch positions can be reached unhindered.
f
The control element must be securely fastened,
but must not be placed under stress by the
fastening.
f
The device must be installed so that tampering
is not possible by simple mechanical measures
(clamping, adhesive tape, etc.).
Electrical connection
WARNING
There will be no safety function if installed or
connected incorrectly. This situation can result
in serious accidents and injuries or even fatality.
f
Installation and electrical connection must be
performed only by qualified personnel.
f
All electrical outputs must have an adequate
protective circuit for inductive loads. The outputs
must be protected with a free‑wheeling diode for
this purpose. RC interference suppression units
must not be used.
Connecting enabling switch
Selecting contacts or contact combinations
Always use a dual‑channel, safe input to connect an
enabling switch to a safety evaluation unit. Use the
recommended contact combination (for example,
see Figure 2).
If you use your own contact combination, please pay
attention to the following notes:
Connect the enabling switch such that
f
Two independent switching contacts or contact
combinations are used.
f
The switching contacts or contact combinations
are either antivalent (one normally open contact
and one normally closed contact) or equivalent
(two normally closed contacts).
The parameters for this connection must be config‑
ured in the safe evaluation unit to suit the switching
contacts chosen and their wiring. For this purpose
use the appropriate parameters:
f
Dual‑channel equivalent evaluation
Both contacts are closed at the same time in the
enabling position (position 2)
f
Dual‑channel antivalent evaluation
One contact is open in the enabling position (po‑
sition 2), the second closed
f
Discrepancy time
Activate the discrepancy monitoring. Because the
two contacts never switch exactly simultaneously,
you must specify a time within which simultaneity
applies. A time of 3 s has proven appropriate for
electromechanical contacts.
f
Resetting after fault detection
Select the parameter such that after a fault the
enabling switch is automatically reset if both
contacts were in the open position (for equivalent
contacts) or one contact was open and the other
closed (for antivalent contacts) and they are then
placed again in the correct position for enabling.
