These multipurpose control boxes are designed for Zone 1 and and 2 areas at risk of gas explosions to IEC/EN 60079-2 and for Zone 21 and 22 areas at risk of dust explosions to IEC/EN 61241-2.
For multipurpose control boxes of category 2 G/D (Zone 1 and Zone 21), the THU850S monitoring unit is used. For category 3 G/D (Zones 2 and 22) it may be sufficient to monitor the internal pressure with pressure monitor DW 812.99 and an appropriate alarm. But if an explosive atmosphere might be present upon switching on or start-up, use of the PS 480 control unit is mandatory. This control unit offers the possibility of prepurging and activation of an alarm or cutout. For applications in areas with a dust explosion risk, prepurging is dispensed with. The multipurpose control box is cleaned prior to operation to prevent dust from being raised during the pressure build-up phase.
The enclosures can be made of stove-enameled sheet steel, stainless sheet steel, or polyester. In addition to standard enclosures, special enclosures are fabricated to customer specifications.