Danfoss VACON OPTE3 - Page 38

C D
BA
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Illustration 9: Grounding in noisy environment with good equipotential. If potentials at points A, B, C and D are very different and cannot be
made similar, cut the shields as in Illustration Grounding in noisy environment with poor equipotential.
If ground potentials of the connected devices are different, cable shield that is connected at both ends causes current to flow in the
shield. To prevent this, the cable shield must be disconnected or cut at some point between the devices (see Illustration 10).
When disturbances are strong, the cable shield can be exposed and then 360 degrees grounded directly to the AC drive ground (see
Illustration 11). When the connection is made like in Illustration 10, grounding should be done at a location nearest to the place
where the disturbances meet the cable.
C D
BA
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Illustration 10: Grounding in Noisy Environment with Poor Equipotential. An Example of Cutting the Shield.
We recommend grounding the cable shield as in examples A and C (see Illustration 11). Do not ground the cable shield as in exam-
ple B.
A B C
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Illustration 11: Grounding the Cable Shield
A
Cable clamp
B
Ground terminal
C
Cable gland
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Cabling
VACON® RS485 and CAN Bus Option Boards
Installation Guide