The control unit types, LCS120, 220 and 260, consist of an aluminum enclosure certified to type of protection increased safety "e" and dust protection "t". It is designed to accommodate control and signaling elements as well as measuring instruments and terminals for intrinsically safe and non-intrinsically safe circuits. And enclosure covers are designed for maximum two or four or nine control/signal/measuring elements for each size of enclosures. All installed and attached components have been tested and certified under separate EU/EC certificate of conformity. Connection to enclosures is by means of explosion proof cable and conduit entries (according to enclosure certificate). Several of these enclosures may be connected in series by suitable certified flameproof unions/bushings. All 3 variants are suitable for permanent/fixed installation inside hazardous area, depending on the type of protection and equipment level of apparatuses installed; it can be operated as category "2" equipment and under appropriate marking stated in this certificate.