SCHMERSAL’s ZQ700 and ZQ900 Emergency Cable Pull Switches are available to perform E-Stop protection for many machines and plants where an emergency stop command must be available over a great span of distance. Schmersal is a designer and manufacturer of machine safety products, industrial switches, position sensors, and related control accessories that meet machine guarding safety requirements of OSHA, ANSI, RIA, and the EU Machinery Directive.
The more robust version is the ZQ900. Using one-spring force it provides E-stop protection for a cable span up to 50 meters (165 feet). For circuit flexibility it is available with either two contacts (1NO/1NC or 2NC) or four contacts (2NO/2NC, 1NO/3NC, or 4NC.) This version has a strong metal housing, a position indicator window for ease of installation, and can be fitted with an indicator light since it has three conduit openings. It is also available with an optional e-stop button integrated on the switch housing.
A compact model is available for use on smaller machinery and in confined areas. The ZQ700 can provide E-Stop protection for up to 10 meters (32 feet) and is available with two contacts (1NO/1NC or 2NC). It has a sturdy, narrow thermoplastic housing.
Both emergency cable pull switches have an integrated reset button because a latching mechanism maintains the emergency stop position when the cable is pulled, and the switch is actuated. The switches also will fail safe: the cable being cut or going slack will also result in actuation and machine stoppage.
These switches feature corrosion resistant housings that are dust- and water-tight (IP67-rated), suitable for harsh environments. They meet emergency stop standards EN ISO 13850 and IEC 60947-5-5.
For ease of installation of the cable assembly, Schmersal also designed a tensioning device, the S900.