Problem: condensed water in electrical systems
For housings with a high degree of protection and thus a high degree of leakproofness, condensed water forms inside if there are temperature differences between the inside and outside temperatures.
Temperature variations do not only occur due to thermal influences from outside – the inner temperature can also increase due to the power loss of the devices installed. The warmer inner air naturally enriches itself with moisture from outside since the housing is not completely gastight.
If the housing now cools down e.g. by switching off the system, the air inside re-releases the moisture and this forms as a film of condensed water on the cool housing walls. Small drops form gradually, which then flow to the lowest point of the housing.
Less relevant is the problem of condensed water formation with normal installation in rooms. As an exception here, the conditions should be mentioned by which high humidity and large temperature variations occur like e.g. canteen kitchens, laundries, car washes etc.
Special caution is necessary with installations of unprotected electrical systems outdoors.
Here the danger of condensed water forming is especially high due to the change between day and night, strong sunshine and cool weather conditions, and the corresponding temperature differences between inside and outside air.
Measures against formation of condensed water
Measures against formation of condensed water
Choosing the installation location
A first aspect is the choice of installation location. Here one can try to avoid large temperature differences in advance.
Technical measures
In every wall-mounted enclosure from ABL SURSUM there is a default potential opening at the lowest point. Collected condensed water can flow through here after puncturing.
Pressure compensation membrane M 12 x 1,5
The best solution, however, is the installation of a pressure compensation membrane. This has an air outlet of up to 120 litres per hour at a pressure difference of 70 mbar. It makes possible even high degrees of protection like IP67 and can be mounted for wall thicknesses of up to 4 mm.
IP degrees of protection acc. to EN 60529
Depending on application and load, switching devices and socket outlet combinations require the appropriate degree of protection. This is characterised by IP and a following number. The first code number specifies the degree of protection against foreign bodies entering; the second code number specifies the degree of protection against water entering.
Thus e.g. electrical equipment, which is used unprotected outside, must at least have IPX3.
