Compact solenoid interlocks for explosion protection
12 April 2010
The safe interlock of guard doors, protecting flaps and covers in cramped surroundings in potentially explosive atmospheres: this is briefly said the task of the solenoid interlock Ex STM 295 steute developed.
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. Despite the compact design the interlock is very robust. The enclosure is carefully encapsulated so that the safety switch can even be applied in a very dirty environment.
Solenoid interlocks like this are applied for safety reasons, i. e. when the machine carries out dangerous (over-travel) movements after been switched off. More often, however interlocks are used, when there are no over-travel movements, as alternative to the usual safety switches. The locked guard guarantees that the work sequence is not interrupted by opening the door. Thus solenoid interlocks make a contribution to higher productivity – even in potentially explosive atmospheres.
Contact Details and Archive...