Ar Safety Switches Connected In Series; Usage Of The Reset Input; Teaching In Actuators - EUCHNER CET3-AR Series Quick Start Manual

AR safety switches connected in series

Usage of the Reset input

In a series connection the reset must always be connected to all switches. A common signal must be used for all switches in the
chain. This can be a changeover switch or the output of a control system. A button is not suitable because Reset must always be
connected to GND during operation.
The reset is used to synchronize the switches connected in series. This action is necessary if synchronization is lost due to
external effects. This situation may be caused by switching off one of the switches in the series. All switches in the chain must
always be reset together, as otherwise the synchronization will fail and as a result the safety outputs will not switch.

Teaching in actuators

It is recommended not to teach-in the actuators in the series circuit, but to teach them in one by one instead.
It is often only possible to teach-in actuators in an installed chain with limitations. Work on the wiring (e.g. during device
replacement) should in general be performed in a de-energized state. On certain systems, it is nevertheless necessary to perform
this work and subsequent teach-in during ongoing operation.
To make this action possible, the input RST must be connected as shown in Figures 1 and 2.
With CET without teach-in input J proceed as follows:
1. Open the safety door on which the switch or actuator is to be replaced.
2. Mount the new switch or actuator and close all safety doors in the chain.
3. Actuate the reset for at least 3 s (24 V on RST).
4. On the safety switch that is positioned at a new actuator, the green LED flashes at approx. 1 Hz and the actuator is
taught-in. This happens for approx. 1 minute - do not switch off during this time and do not actuate reset!
The teach-in operation has ended when all LEDs on the device are off.
5. Actuate the reset for at least 3 s (24 V on RST).
The system re-starts and then operates normally again.
With CET with teach-in input J proceed as follows:
1. Open the safety door on which the switch or actuator is to be replaced.
2. Mount the new switch or actuator and close all safety doors in the chain.
3. Connect teach-in input J of the CET where the switch or the actuator shall be replaced to 24 V DC.
Important: terminal 0V (UCM) has to be connected to 0V during teach-in procedure, not to a different potential or an
output.
4. Actuate the reset for at least 3 s (24 V on RST).
5. On the safety switch that is positioned at a new actuator, the green LED flashes at approx. 1 Hz and the actuator is
taught-in. This happens for approx. 1 minute - do not switch off during this time and do not actuate reset!
The teach-in operation has ended when all LEDs on the device are off.
6. Disconnect input J. The input has to be unconnected during operation. Connect terminal 0V (UCM) back to the original
terminal if necessary.
7. Actuate the reset for at least 3 s (24 V on RST).
The system re-starts and then operates normally again.
Subject to technical modifications, no responsibility is accepted for the accuracy of this information. © EUCHNER 2016
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