Our definition of “Extreme”

Heat, cold, damp, vibrations, corrosion: there are many ambient conditions which conventional switching devices are unable to cope with, even in the short term. For harsh environments such as these we have developed a range of switchgear able to withstand extreme conditions, even in the long term. These products have been so successful internationally that in late 2010 we decided to dedicate a whole business field to them. The name of this business field speaks for itself: “Extreme”.

Switchgear with special degree of protection

Application

Moisture and dampness are often part of the environmental conditions in many application fields of automation. A lot of machines for food production are regularly cleaned by means of a high-pressure washer. In the ships technology and offshore applications the switchgear are also exposed to moisture – just to mention further examples – in cleaning plants or in conveyor systems erected in the open air. For all these applications steute offers high-quality switchgear in IP 66, IP 68 and IP 69 degrees of protection. The range comprises position switches, foot switches, pull-wire switches and safety sensors. „Tried and tested“ under extreme conditions.

Degree of protection IP 66 as per IEC/EN 60529

Many of the switching devices in the standard range made by steute are designed according to degree of protection IP 65 and IP 67 as per IEC/EN 60529. In addition, there are designs meeting even higher requirements regarding resistance to dampness and moisture. One of them is in IP 66 degree of protection. From a distance of 2.5 to 3.0 m, the devices are treated with splashing water which hits the switchgear from different directions at 100 l per minute. The jet diameter is 12.5 mm and the test duration is 1 min/m surface for at least 3 minutes.

Degree of protection IP 69 as per IEC/EN 60259

The test criteria for IP 69 degree of protection are as follows: devices are treated with a hot water jet at 80 °C with a hydraulic pressure of 100 bar from a distance of 100 mm and from different directions. It is thus guaranteed that devices can withstand high-pressure washer jets without their function being affected.

This requirement originated from vehicle construction – building machines are often cleaned in this way, for example. Switchgear protected according to IP 69 can also be applied in hygienic areas of the food industry, however, cleaned with high-pressure water jets and steam.

steute offers a comprehensive range of switchgear in IP 69, including foot switches, pull-wire switches and safety sensors, like the BZ 16, RC Si M30 and RC Si 56. They are well suited to applications till PL »e« per EN ISO 13849-1 or SILCL 3 per EN 62061.

Switchgear for low temperatures

Application

It doesn't go without saying that a switch still works reliably at temperatures of -20, -40 or even -60 °C. On the contrary - comprehensive constructive measures have to be taken to guarantee this feature. steute has qualified several ranges of switchgear for low temperatur – magnetic switches, position switches, belt-alignment switches and pull-wire switches. These switchgear are applied in low-temperature warehouses as well as at cable railways and conveying plants for raw material extraction.

Cold

The climatic chamber in the steute lab enables tests to be performed at temperatures as low as -60 °C. Switching devices suited to low temperatures down to -40 °C, like the magnetic sensor RC M20, are applied in lowtemperature warehouses, as well as in the open air in colder climatic zones (e. g. on conveying systems).

Switchgear for high temperatures

Application

Steelworks, glass processing, foundries: there are a lot of application fields in which switchgear are exposed to high temperatures. steute has developed several series for hot temperature applications suitable for continuous operation at temperatures up to +180 °C. This range comprises foot switches, position switches, magnetic switches and magnetic safety switches. A special challenge are switchgear »fit for the tropics« to withstand high temperatures in connection with high humidity. Very quickly this is a knock-out criterion for conventional switchgear, but not for devices made by steute: owing to a special sealing technology they are carefully and durably protected from letting in moisture.

Heat

At steute, switching devices are tested at temperatures of up to +200 °C. This is a requirement found not only in parts of the process engineering sector, but also in the steel industry and glass processing. Heat is often connected with humidity. For this reason, the criterion »fit for the tropics« is often requested in connection with switchgear.

Switchgear in corrosion-proof design

Application

The criterion of a seawater-proof switch shows which requirements have to be met: the switchgear must be able to work without failures even under corrosive conditions during a long life – in all weathers and waves. The safety sensor HS SI 4 for example meets these requirements without problems as well as the magnetic safety sensor RC SI M30, the position switch ES 13 W and the position switch ES 95 offshore. These switching devices feel fine on offshore platforms as well as in wind power plants, on ships and in submarines.

Salt Mist Test

The saltwater resistance of switchgear is verified by means of a salt test in accordance with IEC/EN 60068-2-52/GL/(cyclic salt mist test). According to the requirements of »Germanischer Lloyd«, specimens are sprayed in four cycles of two hours each and then stored at a temperature of +40 °C for seven days. Switching devices developed for offshore applications – e. g. position switches in series ES 95 have to pass these tests.

Switchgear with high shock- and vibration resistance

Application

The idea for this production range arose from an enquiry of a customer. They were looking for a safety sensor for the position interrogation of a flap fixed near the engine room of a ship. The problem: conventional magnetic safety sensors fail very quickly due to the constant vibrations of the ship's diesel motor. The solution: a vibration-resistant safety sensor on Hall sensor basis.

Meanwhile the product portfolio of vibration-resistant switch - gear has been expanded by explosion-proof safety sensors and micro switches. The application field was also expanded: in packing machines and processing plants switchgear are also exposed to vibrations which, however, must not affect the operating life.

Switchgear used in potentially explosive atmospheres

Impact Test for Ex Switchgear

EN 60079-0 indicates the requirements for testing the mechanical strength of switchgear developed for application in potentially explosive atmospheres. In Chapter 26.4.2, a standard test for checking impact resistance is described. In this test, a sample mass of hardened steel falls from a defined height onto the device.

All steute switching devices for application in Ex zones 1 and 2 (gas Ex), as well as 21 and 22 (dust Ex), have passed this test.