SIEB & MEYER CNC 0610510, Hardware Description

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General Information Regarding the Wiring
Hardware Description CNC 0610510/12 63
9.2 Difficulties of Ground Loop
Even if all ground points seem to have an identical potential, potential differences can
be produced in a ground system by coupling RF signals into a special machine com-
ponent (e.g. motor lines clocked to high-frequency). The magnetic fields that are pro-
duced can be the reason for interferences in the machine or in the control.
Connection Information
The main requirements for a professional grounding according to DIN/EN 60 204-1
(electrical equipment of machines) are :
Direct Connection of the Earth Conductor System
All assemblies of the electrical equipment and the machine(s)
must be connected to the earth conductor system.
Only one PE point exists within the complete system!
All ground connections are connected in a tree-type structure
to the PE point.
Special information:
X The PE point is usually the connecting
point of the PE conductor of the voltage
supply or the earth connector of a sepa-
rate connection to earth of a complete sys-
tem.
X If several points inside of the system are
labeled with PE, all labels except for one
should be marked with the ground symbol
7
.
X Motors must be connected with least im-
pedance to the ground points
7
. Ground
connections to the outputs of the servo
amplifiers must not be made!
Connection example of a machine and the connected CNC with
grounding according to the EMC guidance
X Motors mounted on an insulated machine component such as linear motors,
handheld nut setting units, etc., must be connected to ground with largest sur-
face.
X Earth conductors always must be connected with largest surface. Ground
straps consisting of many thin wires offer a larger surface in contrast to only
one fixed core with thick cross-section. Ground conductors should be as short
as possible.
Motor X
Motor Y
PE
Servo X
Servo Y
FC
PE
Machine CNC
Power
Due to filters or the use of several servo amplifiers, higher leakage
currents (> 3.5 mA) can occur in the earth conductor (PE). In this
case, possibly a residual current operate device cannot be used. Ac-
cording to DIN/EN 50178 - VDE 160 the electronic component must
be equipped with a fixed connector in this case. Besides, warnings
must be provided in the documentation and on the device.
Additionally, an earth connector of at least 10 mm² cross-section
must be used or a second earth connector must be connected in
parallel to the earth connector with separate terminals.
Annotation:
The minimum cross-section has been chosen considering its me-
chanical stability.