The safe interlock of guard doors, protecting flaps and covers in cramped surroundings in potentially explosive atmospheres: this is briefly said the task of Steute’s solenoid interlock Ex STM 295. As basis the developers took the well-tried switch insert of the Ex 95 series housed in a glass fibre reinforced plastic enclosure. An electro-mechanical interlock keeps the guard closed. The switching element with 2 NC and 2 NO contacts offers the condition for a flexible switching on. Furthermore the user can choose between versions with operating current principle and no-load principle which is the favourite of the trade associations.
Thanks to the certification for the ex zones 1 and 2 (gas ex) as well as 21 and 22 (dust ex) the Ex STM 295 can generally be applied in potentially explosive atmospheres. In connection with the interlocking monitoring module SRM it is ideal to be applied up to performance level e acc. to EN ISO 13849 or SIL 3 acc. to EN 61508. The enclosure is carefully encapsulated so that the safety switch can even be applied in a very dirty environment.