1056748 03/2023
1056748 03/2023
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Assembly
7.2.3 EMC compatible wiring
Harmonic Drive SE recommends the use of shielded motor and encoder cables only.
The outer shield of encoder and motor power cables must be connected on the controller side. On the motor side, the
outer shield of Harmonic Drive
®
Power Cables as well as encoder cables is already connected in the connector. On the
controller side, the shield of the power cable should be connected as close as possible to the power terminal, namely
over a large area on the conductive earthed housing of the controller or on a shield connection rail. The unshielded open
strands should be connected as short as possible to the power terminal of the servocontroller.
For a large area shield connection, the end of the cable sheath is exposed; then the inner outer shield is brushed on and
laid back over the cable sheath.
Illustration 1
For good strength, the shield is wrapped with a copper tape and the two edges of the copper tape are fixed with heat
shrink tubing.
Illustration 2
The shield of the encoder cable is also connected flat to the encoder connector housing. For Harmonic Drive
®
Encoder
Cables with pre-assembled D-Sub connector, the outer shield is already connected to the connector housing.
Often twisted pair strands in encoder cables are provided with separate inner shields. For EMC reasons, these inner
shields are not connected to the connector housing on the motor side. If cables with open strands on the controller side
are used, the encoder plug must be assembled by a specialist. It must be ensured that the inner shields - if present - are
laid flat on the plug housing of the encoder plug on the controller side.
Example of internal wiring of the shielding
Illustration 3
In this example it can be seen that the inner shields of the signals Clock, Data and UBAT are not connected to the
connector housing on the motor side.
The inner shields are connected to pin 17 on the motor side - this is important when connecting actuators with
connecting cables, such as the CanisDrive
®
Servo Actuator. This ensures that the inner shields are also connected in
the cable tail on the motor side. For actuators with a plug connection on the motor housing, the inner screens must
remain open. The inner screens are only connected on the controller side. The controller specific recommendations or
specifications must be observed. If there are no separate connections for the inner screens on the controller side, the
inner screens must be connected to the housing of the connector plug (usually D-SUB) on the controller side.
Motor
Controller
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Assembly Instructions Servo Actuators
