PSE EX: Piezo switch for use in hazardous environment with ATEX / IECEx – Certification
Flammable substances such as gases, vapors or mist which are released into the environment, e.g. while in production, during transportation or storage, may ignite and pose serious consequences for persons and property. The same is true for dust which may develop in conjunction with air to an explosive atmosphere. To ensure security in these areas, the Device Directives 94/9/EC was developed for products and protection systems. The purpose of the guidelines is the protection of personnel and devices which are working in such hazardous areas. This is done by eliminating all possible sources of fire and ignitions in the products and systems used in these areas.
The PSE EX family is certified according to ATEX and IECEx regulations. The area of application is consistent with that of the device group II (other areas than mining). It comprises systems with a potentially explosive atmosphere consisting of a mixture of air and gases, vapors or mists or in industrial areas where dust-air blends infuse the atmosphere and the danger of a dust explosion can arise.
The approval marking is Ex II 2 GD (according ATEX regulations), Ex ib IIC T6 ... T5 Gb and Ex ib IIIC T85 ° C ... T100 ° C Db (according IEC regulations) for gases and dust.
The temperature class was extended from T4 to T5 and T6. Therefore the permissible power dissipation of the PSE EX was limited accordingly so that the piezo switch is intrinsically safe according to EN60079-11. In addition, the flammability group was increased from IIB to IIC, respectively IIIC (gas, dust). This extension will allow the use of the PSE EX in atmosphere with further type of gases, combustible dust, ignitable fibers and flyings.
Typical applications include oil and gas exploration rigs, petrochemical facilities, environments of transportation and storage of combustible materials, paint mixing devices, painting devices, grain mills, wood processing industry, chemical plants etc.
The PSE EX standard models are available with mounting diameters of 16, 19 and 22 mm with pin connectors and housing colors in red, green or natural aluminum. On request other colors, housing diameters and connection versions are obtainable. The switches for hazardous use have a label with the particulars of the certification and an identification number. Installation instructions are included in the packaging according to the ATEX directives. For detailed specifications see datasheet PSE EX.