Friction causes the castor or wheel to become electrically charged and the charge cannot flow away. The next contact with the earth then causes the voltage to discharge.
If castors or wheels are made of non-conductive materials such as plastic, a well-known effect occurs: Friction causes the castor or wheel to become electrically charged and the charge cannot flow away. The next contact with the earth then causes the voltage to discharge.
In many cases this is just a nuisance, but under certain circumstances it can represent a serious hazard. In such cases, when purchasing castors and wheels, care must be taken that they are electrically conductive.
Among the areas in which electrical conductivity plays an important role are, among others, pharmaceuticals and medicine, the automotive and electrical industries. Electrically conductive castors and wheels are also required in potentially explosive atmospheres, such as those found in chemical, mineral oil and pyrotechnic facilities.
Electrical conductivity according to DIN EN 12527-12533
According to the standards DIN EN 12527 to 12533, an electrical conductivity for castors and wheels is present if the ohmic resistance does not exceed 104 Ω. They are considered antistatic if the ohmic resistance is less than 107 Ω. The standards prescribe a test procedure to be used for testing the leakage resistance.
In the case of non-conductive materials, elements can be added to ensure that the castors and wheels are electrically conductive. This makes it possible to use plastic castors and wheels in such applications, for example. During operation of the transport equipment, the electrical conductivity of the castors and wheels can be reduced by dust, paint, acids, alkalis, impacts and overloading. The electrical energy is then no longer discharged or is not completely discharged. Therefore, the effectiveness of the conductivity must be checked at regular intervals.
We are happy to advise you on questions regarding the electrical conductivity of TENTE castors and wheels - please contact us! In addition, we would be happy to develop individual system solutions to meet your specific requirements on request.