Page 12 - KNX Certification Scheme for products

KNX TUTOR SEMINAR

4.2 Selected aspects of product hardware testing
The requirements given below refer to EN 50491-x (requirements Home and Building
Electronic Systems), which serves as the minimum requirement (apart from a suitable
product standard) for hardware certification.

4.2.1 Electrical safety
Requirements concern the safe separation of bus from hazardous voltages and currents
of other electrical circuits (internal and external).
“Safe separation” according to the relevant international standards means the “separation
of electrical circuits by basic and additional protection … or an equivalent protective
measure”.
The following aspects are judged in this context:
insulating capacity of creepage distances and clearances
resistance of housing and carriers to environmental conditions

The electrical safety requirements are defined in EN 50491-3

4.2.2 Functional safety
The manufacturer presently confirms that the product, properly installed and maintained,
does not create hazardous situations in the case of normal operation or in the case of
foreseeable abnormal conditions. These requirements are defined in EN 50491-4.

4.2.3 Electromagnetic compatibility (EMC)
The term “electromagnetic compatibility” signifies “the capability of a device to operate
satisfactorily in an electromagnetic environment, without itself causing electromagnetic
interference that would be unacceptable to other devices present in this environment.
In order to ensure this, the EN 50491-5 defines a number of requirements and tests.

4.2.4 Environmental conditions

EN 50491-2 defines a number of environmental tests, during which it is verified whether
the product is e.g. able to withstand extreme heat, cold, humidity, shock and temperature
changes. The degree of protection offered by the housing to the user is also tested
(protection class).
After passing the environmental tests, the devices should be examined again on safety
aspects.

4.2.5 Reliability and quality

Unless otherwise indicated by the manufacturer, a service life of at least 10 years shall be
guaranteed for devices.
This must be declared accordingly at the registration stage. If this life time is not
predominantly determined by switching cycles, the manufacturer can substantiate the life
time of a product by calculating its “FIT” (Failure in Time) value, i.e. the sum of the
statistical values of the failures in time of the used individual electronic components.

Home and Building Management Systems KNX Association
KNX Certification Scheme for products KNX Certification Scheme_E0714a.doc 12/15