Danfoss VLT HVAC Drive FC 102 Design Manual page 41

Introduction
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1 Ground wire
2 Screen
3 AC mains supply
4 Frequency converter
5 Screened motor cable
6 Motor
Illustration 2.25 Leakage Currents Cause
If the screen is to be placed on a mounting plate for the frequency converter, the mounting plate must be made of metal,
because the screen currents have to be conveyed back to the unit. Moreover, ensure good electrical contact from the
mounting plate through the mounting screws to the frequency converter chassis. Use of unscreened cables does not
comply with all emission requirements, although the immunity requirements are observed.
To reduce interference level from the entire system (unit + installation), make motor and brake cables as short as possible.
Avoid placing cables with a sensitive signal level alongside motor and brake cables. Radio interference higher than 50 MHz
(airborne) is generated by the control electronics. See chapter 5.7 EMC-correct Installation for more information on EMC.
WARNING
In a domestic environment, this product has the potential to cause radio interference, in which case supplementary
mitigation measures are required. This type of power drive system is not intended to be used on a low-voltage public
network which supplies domestic premises. Radio frequency interference is expected when used on such a network.
MG16C202
Design Guide
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Danfoss A/S © Rev. 05/2014 All rights reserved.
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