The new lifeline from Schmersal
26 Nov 2007
Schmersal has introduced a range of pull-wire, emergency-stop switches and wire-tensioning devices for safety-oriented applications ranging from conveyors to large and complex machinery and plant.
The new pull-wire switches are available in two basic versions – the ZQ 900 and ZT 900. The ZQ 900 is a safety emergency switch, similar to an emergency-stop switch, which fulfils the requirements of the new standard BS EN ISO 13850:2006 by latching in the emergency-stop position if actuated and requiring a manual reset by means of a release button. The ZT 900 version has non-latching contacts and is suitable for non safety-related applications. Both include wire breakage detection that automatically switches to the ‘OFF’ position if the actuating wire breaks or is removed.
Schmersal has also launched the S 900 wire-tensioning device, an innovative and convenient feature for both ZQ and ZT ranges that facilitates the installation of both pull-wire switches. It can be used for either one or both ends of the actuating wire and replaces traditional clamps to increase or decrease the tension of the wire by up to 12 cm without being twisted.
Both switch ranges can be equipped with a maximum of four contacts, be actuated from any point of the wire, and be used as universal command devices. The convenient location of the reset button on the ZQ 900 allows the triggering of the safety function to be monitored, even at large distances. Alternatively, an indicator lamp and additional, optional emergency-stop switch can also be fitted to enable activation of the emergency-stop function from a workstation.
The ZQ and ZT’s robust zinc metal enclosures are IP65-rated making them suitable for use in harsh environments. Their compact size and three M20 cable entries make installation and connection easy, regardless of the mounting situation. A sight glass also enables easy inspection of the wire tension.
For further information on the ZQ/ZT 900 pull-wire, emergency-stop switches and the S 900 wire-tensioning device, call the Schmersal customer support centre on 01684 571980 or visit www.schmersal.co.uk