Safety relay ISK 74-31
3.
General
The ISK cable transmission system transmits information on the position of the safety contact edges
mounted on the sliding gate to the stationary switching device inductively and without causing any
wear off material. Auxiliary power and information is transmitted through a closed conductor loop
consisting of the doorframe and steel cable.
The system registers both the activation and interruption of the safety contact edge.
The switching device furthermore offers the possibility of connecting two stationary safety contact
edges for protecting shearing points on the secondary closing edge.
4.
Function
The safety relay is designed for outdoor use and can be operated with 230 V mains voltage and
24 V AC/DC.
The switching device is designed for connecting up to four safety contact edge circuits. Two channels
(SKL open and SKL close) are available for the safety contact edge (SKL) on the gate leaf and another
two channels are available for the safety contact edges on the guidepost. The cable transmission
system monitors the movable safety contact edges on the gate inductively and without causing any
wear. The stationary safety contact edges are connected directly to the switching device.
The switching device continuously monitors these four safety contact edges for activation and
interruption (cable break). In the event of a fault, one of the two stop commands (stop during opening
or stop during closing) is issued to the relevant safety contact edge circuit. A terminating resistor has
been integrated into the trailing edge of the relevant safety contact edge circuit in order to enable the
closed-circuit current of the entire system to be monitored. If there is nominal closed circuit current,
the relay switching contacts are energized and close. If the safety contact edge is activated or the
safety circuit is interrupted, the relay switching contacts open.
The switching states of the relay switching contacts and the relevant operating voltage are indicated
by LEDs.
5.
Proper use
The switching device complies with EN 954-1 "Safety-related parts of control systems", Cat. 3.
The switching device has a redundant structure with two, two-way polling, positively driven safety
relays per channel in compliance with Cat. 3.
The switching device furthermore complies with the latest EN 12978 "Safety devices for power
operated doors and gates" standard and EN 12453 "Safety in use of power operated gates".
Any uses above and beyond these uses constitute improper use. The manufacturer does not accept
any liability for damage arising from improper use.
The device may only be used in special applications with the manufacturer's express consent.
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