Products Catalog

Specification

The Guardmaster Ex range of safety switches are specifically designed for potentially explosive atmospheres. They retain the safety features and operating principles of the conventional Guardmaster switches. They incorporate a sealed flameproof contact block, making them suitable for use in European Zone 1 and Zone 2 environments. In the US and Canada, these products can be used in areas classified as Class 1, Division 2 in Groups A ( acetylene) , B ( hydrogen) , C ( ethylene) and D ( propane) . All the Guardmaster Ex switches conform to the exacting standards required by the European harmonized standards. These switches carry the classification EExd IIcT6.
EEx equipment conforms to types of protection standardised by CENELEC ( European standards) , EN50014 and EN50018 respectively and BS5501 parts 1-V.
The d suffix indicates that the contact block in the switch is a flameproof enclosure and is designed to ensure that if an internal explosion occurs it will be contained with the enclosure. The designation II indicates use in surface industries and c refers to the group of gases for which the switches are suitable. The designation T represents the surface temperature classification of the switch. These switches have been tested with an ambient temperature of 60° C as opposed to the normal test limit of only 40° C, allowing them to be used in gases having a low flash point.
It should be noted that these groups refer to the explosion-proof qualities of the switches and not corrosion-resistance characteristics. Special precautions may be required to protect the vulnerable parts such as PVC-covered cables against attack by certain corrosive elements and physical damage.