The explosionproof switchgear combinations are intended for use in Zone 1 and Zone 2 explosive gas atmospheres and Zone 21 and Zone 22 explosive dust atmospheres according to IEC/EN 60079-0 and IEC/EN 60079-2. IEC/EN 60079-2 'Equipment protection by pressurization p’ covers explosionproof equipment for equipment protection levels (EPL) 'Gb’ (Zone 1), 'Gc’ (Zone 2), 'Db’ (Zone 21), 'Dc’ (Zone 22) with the levels of protection 'pxb’ and 'pzc’.
Depending on the version in relation to the respective level of protection, a complete pressurized switchgear combination comprises a
level of protection «pxb»
– control unit PS 850S (EPL Gb or Db)
– control unit PS 860S (EPL Gb or Db)
level of protection «pzc»
– control unit PS 830 (EPL Gc or Dc)
– control unit PS 840 (EPL Gc or Dc)
the purging valve, the separate outlet valve (only for control unit PS 830) and the enclosure. With the other control units, the outlet valve is integrated in the control unit. The outlet valves also act as spark and particle barriers.
The parameterization of the control units is carried out directly on the unit. An external, intrinsically safe remote control with an integrated digital display is available. The controls and the digital display of control unit PS 830 are integrated in the front of the unit.
The control unit also meets the requirements of IEC/EN 61508-7 'Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 7: Overview of techniques and measures (SIL 2)’. According to EN 61508- 7 (SIL 2), safety-related parts shall be built in such a way that
1. a single fault in any of these parts shall not lead to the loss of the safety function and,
2. whenever possible, the single fault is detected.
The enclosures can be made of stainless steel (AISI 316L or 304) or stove-enamelled steel. In addition to a standard range with 16 different enclosure dimensions, stainless steel enclosures can be made to customer specifications. Further empty Ex enclosures from well-known manufacturers are included in the certificate. This means that existing constructions or dimensions can be taken into consideration in mechanical engineering. Various manufacturers of empty enclosures offer the same dimensions for both the industrial and the Ex sector.
All the controlgear combinations built using the standard enclosure range are prepared for wall mounting. The customized stainless steel enclosures are generally freestanding and feature a base. Depending on the size of the enclosure, the use of feet or support systems means that they can be used as freestanding or hanging units.