The drive must be grounded to ensure that it operates safely and reliably. If the drive is
operated with insufficient grounding, then the protection and monitoring functions can fail.
Death, serious injury, or material damage will result.
To ensure the correct functioning of the protection and monitoring equipment, ground the
To ensure the drive operates safely, connect a protective grounding conductor.
A grounding bar and a grounding lug can be found in the lower area of the cabinets. Grounding
bar and grounding lug are used for grounding the components installed in the cabinet.
Laying the signal lines
Malfunction due to common cable installation
Malfunctions can occur in the converter if cables with differing voltage levels are laid together
with internal cables in one cable duct in the cabinet.
Do not run cables coming from the outside, for example to the terminal strips, together with
internal cables in one cable duct.
All signal lines must be shielded. The cable shield should be braided, because cables shielded
by tape or foil are five times less efficiently protected against interference. Always ground the
cable shields at both ends. Contacting at one end is advantageous in exceptional cases only.
Clamp the shield of incoming analog and binary cables to the shield busbar at the entry point
into the cabinet. Continue running the cable, still shielded, to the terminal strip or board. No
shields are connected to the terminal strips or boards.
Serial connecting cables must be shielded. Place the shield on the metallic connector housing.
Also connect the shield to the shield rail. Do not connect the cable shield to a ground pin of
The connector housing and front plate of the boards do not provide adequate cable shielding.
Connect the cable shields at both ends to the shield rails in the cabinets. Always use shielded
analog signal cables, regardless of whether they are installed inside or outside cabinets. In
order to increase the effectiveness of the shielding, ground spare conductors at both ends.
SINAMICS SM120 6SL38715
Operating Instructions 07/2015
6.6 Laying the signal lines