1st edition, 20.04.2021
7000.05072, 1st edition, 20.04.2021
7000.05072
Installation
61
Problem solutions
The interference may vary depending on load and installation.
The mentioned variants are effective only if the following chapters are followed correctly.
4.3.2
Functional earthing
DANGER
DANGER
!
Danger to life through ground leakage currents
≥
3.5 mA
Check the grounding of the devices for proper installation.
The grounding system is essential for discharging parasitic current and for a potential distri-
bution in the system that is as uniform as possible. The most efficient systems have a star or
mesh shape. A star-shaped connection is easier to implement.
Ensure an adequate cross section and a very good electrical ground connection so that
the contact resistances are low not only for the low-frequency currents.
The ground connection can be improved, e.g., by removing the oxide layers from the
ends of conductors with fine sandpaper.
For electrical safety:
Ground in accordance with current standards and guidelines.
Use separate protective conductors (PE) for all necessary parts (e.g., mains supply,
motor, controller).
Keep grounding cable as short as possible.
For functional earthing:
Use a braided shield that is meshed as tightly as possible.
Direct contact with the grounding plate is to be preferred.
Therefore, avoid contact with the controller and then with the grounding plate.
Connections made over a large surface area are to be preferred.
Solution
Mode of action
Benefits
Disadvantages
3-phase common-mode
choke / ferrite ring around
all motor phases
Removes common-mode
interference of the
motor
Removes RF common-
mode interference
Fast testing possible
Does not remove all inter-
ference
Fabrication necessary
PWM motor filter
(e.g., EFM 5003 6501.0035
7)
Removes switching noise
on the motor cable
through DC averaging
Interference limited to
input side
Does not remove all RF inter-
ference
Input filter upstream of
the controller
(e.g., EFS 5004 6501.00350
)
Removes interference of
the switching regulator
and part of the motor
interference on DC net-
works
Pass an interference volt-
age measurement with
correct wiring
Does not remove interference
on the motor side
Mains filter upstream of
the switching power
supply
Removes common-mode
interference of the
power supply
Very cost-effective solu-
tion
Often only effective for
power supply
Does not remove all inter-
ference