A further "Extreme" criterion is suitability for low temperatures. The Ex 99 series can be used in temperatures down to -60°C, 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 -60oC 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.