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9.2 EMC-electromagnetic compatibility
To ensure the electromagnetic compatibility the following points must be observed for
cable installation:
Earth / ground to ensure EMC
• Protection earth
It is important to connect the HYDROVAR to PE, because of the earth leakage
current.
• HF earth connection
Ground cables should be as short as possible and with lowest impedance.
Signal cables
Control and signal cables should be screened types to prevent disturbances from outside.
The screen should be only connected to ground on one side; otherwise it is possible that
the screen has a ground current. The screen should be extensively connected with cable-
clips to HYDROVAR GND (use pre mounted cable-clips).
To connect a screen with lowest impedance to ground, remove the isolation from the
signal cable and connect the screen extensive to ground.
Signal cables must be installed separate from motor- and power- supply cables
If signal cables are installed in parallel to power supply cables (motor cables) for a longer
distance, the distance between these cables should be more than 200mm.
Don’t cross power cables with control cables-if this is not possible, cross them only in an
angle of 90°.
Pre-mounted cable-clips