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4.3.2
Example of correct EMC connection
An example of correctly connected shielded cables is shown below.
Figure 4-3
4.3.3
Line short-circuit power
Information on line short-circuit power
The internal switching elements, fuses, etc. have a limited deactivation capacity. The devices
may therefore be used only in conjunction with the back-up fuses (gl fuses) specified in the
technical data. The current-limiting effect of these fuses guarantees safe operation of the
equipment. The specification of a maximum short-circuit power is therefore superfluous.
The minimum short-circuit power of the line supply should be greater than the rated
apparent power of the converter by a factor of at least 10 in order to ensure functionally
reliable line-side converter operation.
On standard devices, the integral line reactor has a U
Optional: Line reactor with higher inductance, e.g. 6 %.
In equipment with a line-side converter transformer, there is usually no line reactor.
4.3.4
Interference immunity
Line harmonics and commutation notches
Standard EN 61800-3 defines the compatibility levels with respect to harmonic voltages for
industrial environments:
• DYNAVERT I devices meet the requirements of Class 3 of this standard (THD = 10 %).
• In certain circumstances, commutation notches have a greater effect than would be
expected according to their frequency analysis. For this reason, different compatibility
levels are defined for them:
notch depth of 40% and an area of 250 % x degrees.
DYNAVERT I devices are suitable for both values.
Installation and Operating Instructions for LOHER DYNAVERT I Series 7
Operating Instructions, 10/2022, 4BS0745-002
Shield connection for cable type NYCWY
Preparations for use
of 4 %.
k
4.3 EMC
49
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