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Connecting
3.3 Installing the Power Module
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA
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Cable routing and shielding
● All inverter power cables (line supply cables, connecting cables between the braking
chopper and the associated braking resistance as well as the motor cables) must be
separately routed away from signal and data cables. The minimum clearance should be
approx. 25 cm. As an alternative, the decoupling can be realized in the control cabinet
using metal partitions (separating elements) connected to the mounting plate through a
good electrical connection
● The cables from the line supply to the line filter must be routed separately away from non-
filtered power cables with a high noise level (cables between the line filter and inverter,
connecting cables between the braking chopper and the associated braking resistor as
well as motor cables)
● Signal and data cables as well as filtered line supply cables may only cross non-filtered
power cables at right angles
● All cables should be kept as short as possible
● Signal and data cables and the associated equipotential bonding cables must always be
routed in parallel with the smallest possible clearance between them
● Shielded motor cables must be used
● The shielded motor cable should be routed separately away from the cables to the motor
temperature sensors (PTC/KTY)
● Signal and data cables must be shielded.
● Especially sensitive control cables - such as setpoint and actual value cables - should be
routed without any interruption with optimum shield connection at both ends
● Shields should be connected at both ends to the grounded enclosures through a good
electrical connection and through a large surface area
● Cable shields should be connected as close as possible to where the cable enters the
cabinet
● EMC shield bars should be used for power cables; the shield connection elements
provided in the inverter should be used for signal and data cables
● If at all possible, cable shields should not be interrupted by intermediate terminals
● Cable shields should be retained both for power cables as well as for signal and data
cables using the appropriate EMC clamps. The shield clamps must connect the shield to
the EMC shield bar or the shield connection element for control cables through a low
inductive connection through a large surface area.
● Only metallic or metallized connector enclosures must be used for plug connectors for
shielded data cables (e.g. PROFIBUS cables)