Danfoss VLT FC 300 Instruction Manual page 55

VLT ® Automation Drive FC 300
Instruction Manual High Power
3.78: Compact IP 21 (NEMA 1) and IP 54 (NEMA 12) enclosure E1
3.5.3. Grounding
The following basic issues need to be considered when installing an adjustable fre-
quency drive, so as to obtain electromagnetic compatibility (EMC).
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Connect the different ground systems at the lowest possible conductor impedance. The lowest
possible conductor impedance is obtained by keeping the conductor as short as possible and by
using the greatest possible surface area.
The metal cabinets of the different devices are mounted on the cabinet rear plate using the lowest
possible HF impedance. This prevents having different HF voltages for the individual devices and
prevents the risk of radio interference currents running in connection cables that may be used
between the devices, as radio interference is reduced.
In order to obtain a low HF impedance, use the fastening bolts of the devices as HF connections
to the rear plate. It is necessary to remove insulating paint and the like from the fastening points.
Safety grounding: Please note that the adjustable frequency drive has a high leakage
current and must be grounded appropriately for safety reasons. Always follow local safety
regulations.
High-frequency grounding: Keep the ground wire connections as short as possible.
MG.33.U1.22 - VLT ® is a registered Danfoss trademark.
3. How to Install
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