Table of Contents
Advertisement
Electromagnetic Compatibility Requirements
This product complies with EN 55011 (CISPR 11) Group 1, Class A for conducting emissions. The product exceeds the
EN55011 (CISPR 11) Group 1, Class A limit for radiated emissions by less than 10 dB when measured on a test site at a
distance of 30 meters. Therefore, some site preparations may have to be done in order to comply with the Class A limit in
the frequency range of 30 MHz to 1 GHz for radiated emissions at 30 meters from the exterior wall of a building in which
the equipment is installed. See the figure below for an illustration of the site calculations.
To obtain the necessary attenuation at the Customer's site, perform these calculations (if the calculated site attenuation (A)
is less than 10 dB, contact the Technical Regulatory Support Engineer (TRSE) in your country):
1.
The attenuation of a concrete wall (W) (without any openings) = 10 dB
2.
The distance (D) (the distance from the equipment to the exterior wall plus 30 meters) increases the attenuation by X
and can be calculated as follows:
X = 20 * log (D/30)
Where:
X = attenuation in dB
D = distance in meters
3.
The total attenuation (A) is calculated as follows:
A = n * W + X
Where:
A = total attenuation in dB
n = number of concrete walls within distance D
Figure Notices-2:
Measuring Point
30 m
D
Electromagnetic Emission Measurement
Building in which the
Equipment is installed
W
Equipment
QBEMC.WPG
Advertisement
Chapters
Table of Contents
