IMO iDrive Instruction Manual page 22

A ferrite choke in the output of the main circuit can suppress conducted noise. To limit the effects
of radiated noise, unscreened motor cable should be put in an earthed metal conduit. Do not run
control cables inside conduit or within 30 cm of the motor cables.
If control/signal cables must cross over motor cables, ensure that they do so at right angles (90°).
The supply and output (PE) terminals have to be connected to ground to increase noise immunity
of the integrated EMC filter.
In order to prevent noise interference resulting in inverter operation error, wire of control circuit
should be shielded and twisted. Please refer to following diagram, connect shielded wire to
ground terminal. The wiring distance should be less than 50m.
To ground (PE) terminal
Earth / ground wiring should be made as short and thick as possible. Copper braided tape is better
than cable for this application, but not always practical.
Do not 'daisy-chain' the earth / ground of the inverter to other equipment. Connect the (PE)
terminal to a centralized main earth / ground point and 'star' connect all other equipment ground
wires to this point.
Do not make a loop when several inverters share a common ground point.
(a) Good
To ensure maximum safety, use correct wire size for the main power circuit and control circuit
according to the required wiring regulations.
On completion, check that the wiring is correct and terminal screws are secured.
Chapter 3 Environment description and installation
Shield
PVC coating
Wrapped with
insulating tape
(b) Bad
3-12
Do not connect this end
(c) Bad