Switchgear In The Tough Corrosion Protection Test

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-05-24 11:12

The bar is high: the switchgear in Steute's “Extreme” range should have a long service life that far outstrips conventional products. This applies e.g. B. for use in offshore technology, in process plants or at handling facilities in ports.

High quality components

The design features of these switching devices such as foot switches, cable pull switches, position switches and sensors include

• an effective seal
• highly resilient plastic or specially coated aluminum as housing material
• Screws and other fasteners made of high quality stainless steel.

Picture gallery

Relevant tests document the fulfillment of the requirements that are made in this area of application. “Classics” are, for example, the application of spray water to determine the IP protection class and salt spray tests in accordance with DIN EN ISO 9227. These tests are mostly carried out in Steute's own laboratory or also at specialized service providers and test organizations.

Laboratory tests vs. reality

But do the laboratory tests really reflect reality? This question has been and will be answered very comprehensively in a test series that has been ongoing since September 2017. On the island of Helgoland, Fraunhofer IFAM operates a so-called field outsourcing test bench. There, components are attached to a test rack and lowered - directly at the pier, either in the spray or in the alternating water area (tidal range) and thus under very real conditions. In addition to the salt water and the weather, other factors such as fouling (fouling by algae) also have an effect on the test specimens, which are usually examined on land for a period of one year.

Machine safety dossier 2019

Functional safety in all facets

The aim of the tests is to expose the switchgear to extremely extreme and dynamic requirements in addition to the standard-compliant tests in order to be able to better identify weaknesses in the devices. This goal is achieved.

Survived in very good condition

In general, the optical tests and function tests give a positive picture: Even after a year in the tidal range or under splashing water, the devices of the various series are fully functional. Even labels and applied laser inscriptions are still available and legible. The pre-treated and powder-coated housing z. B. the foot switch are in very good condition, the "interior" such as switch inserts, switch plunger and pedal axles are also corrosion-free.

One of the unexpected results that have occurred so far has been corrosion on the housings of a switch series, but this was due to material problems at the supplier. The good test results for all plastic housings and actuators were not unexpected, but very gratifying. From this, the designers draw the conclusion that they will substitute metal even more intensively in the future - even for the mechanically more stressed actuators.

Better than laboratory tests

The test series on Helgoland will definitely be continued. For example, new cable pull switch series are currently being tested and will be brought ashore in April 2020 for an intermediate inspection.

Of course, the environmental conditions on the quay wall on Helgoland go far beyond the requirements that users of Steute's extreme switching devices usually place. But as limit tests, they allow the targeted detection of weak points. They are also more realistic than the standard-compliant corrosion tests that take place under constant conditions. In practice, on the other hand, there are rather changing stresses such as temperature, humidity, current, exposure to salt water or extremely high stresses due to a single factor, in this case due to saline liquids.

Nano coating

Protect die-cast parts from corrosion

And it goes on

Dipl.-Ing. (FH) Rainer Lumme, Product Manager Extreme, steute Technologies GmbH & Co. KG, Löhne

The reality is often even more complex than the fairly realistic conditions in the port of Helgoland. This is shown by the example of Steute's extreme foot switches on the quay wall of a handling facility in another German North Sea port. In addition to salt water, other corrosive or aggressive media act on the switches here: gull droppings. Even these extreme conditions could not affect the function of the switches with which the cable winches on the mooring hooks on the quay wall for cargo ships were operated. (jv)

* Dipl.-Ing. (FH) Reiner Lumme, Product Manager Extreme, steute Technologies GmbH & Co. KG, Löhne