New Ex position switches with or without safety function

"Extreme' conditions include use in explosive environments. These new switching devices have therefore been tested and approved in accordance with ATEX and IECEx for use in gas Ex zones 1 and 2, as well as dust Ex zones 21 and 22.

A further "Extreme' criterion is suitability for low temperatures. The Ex 99 series can be used in temperatures down to -60degC, making high demands on design, especially housing construction and sealings.

The housings in the new position switches are therefore made out of high-quality fibreglass-reinforced plastic. This material guarantees that even after an impact test at -60degC the high protection class of the switchgear (IP 66) is maintained.

A further aspect to which the designers have dedicated a great deal of attention is the sealing. The sealing of the housing cover is completely vulcanised, while the sealing of the plunger features a redundant sealing system, comprising an external sealing cuff able to withstand low temperatures and an internal Teflon sealing ring.

As is usual with steute position switches, a wide range of actuators is available - for example plungers, roller plungers, roller levers, parallel levers, turning levers, adjustable turning levers and push buttons. Regarding switching inserts, users can choose between different variants with slow-action or snap-action. A function for safety-related applications is a further option.

The extended (low) temperature range of this new series of Ex norm switches also increases its field of application, e.g. into the oil & gas industry (onshore and offshore) or shipping technology (ships travelling the Arctic). The standard dimensions of the new "Extreme' switchgear series facilitate integration in a surrounding construction.

More information about the Ex 99 position switches can be found at www.4top.co.uk.