Siemens 6RA7086-6KS22 Operating Instructions Manual page 91

05.05
Rule 9
The shields of digital signal cables must be connected to ground at both ends (source and
destination). If there is poor potential bonding between the shield connections, an additional
potential bonding cable of at least 10 mm² must be connected in parallel to the shield to reduce the
shield current. Generally speaking, the shields can be connected to the cabinet housing (ground
at several points. The shields may also be connected at several locations outside the cabinet.
Foil-type shields should be avoided. Their shielding effect is poorer by a factor of 5 as compared to
braided shields.
Rule 10
The shields of analog signal cables may be connected to ground at both ends (conductively over a
large area) if potential bonding is good. Potential bonding can be assumed to be good if all metal
parts are well connected and all the electronic components involved are supplied from the same
source.
The single-ended shield connection prevents low-frequency, capacitive noise from being coupled
in (e.g. 50 Hz hum). The shield connection should then be made in the cabinet. In this case, the
shield may be connected by means of a sheath wire.
The cable to the temperature sensor on the motor (X174:22 and X174:23) must be shielded and
connected to ground at both ends.
Rule 11
The RI suppression filter must always be mounted close to the suspected noise source. The filter
must be mounted over the largest possible area with the cabinet housing, mounting plate, etc.
Incoming and outgoing cables must be routed separately.
Rule 12
To ensure adherence to limit value class A1, the use of RI suppression filters is obligatory.
Additional loads must be connected on the line side of the filter.
The control system used and the other wiring in the cubicle determines whether an additional line
filter needs to be installed.
Rule 13
A commutating reactor must be installed in the field circuit for controlled field supplies.
Rule 14
A commutating reactor must be installed in the converter armature circuit.
Rule 15
Unshielded motor cables may be used in SIMOREG drive systems.
The line supply cable must be routed at a distance of at least 20 cm from the motor cables (field,
armature). Use a metal partition if necessary.
Footnotes:
1) Signal cables are defined as:
Digital signal cable:
Pulse encoder cables
Serial interfaces, e.g. PROFIBUS-DP
2) The term "Ground" generally refers to all metallic, conductive components which can be
connected to a protective conductor, e.g. cabinet housing, motor housing, foundation grounder,
etc.
Siemens AG 6RX1700-0AD76
SIMOREG DC Master Operating Instructions
Analog signal cable.:
e.g. + 10 V setpoint cable
Connections
2)
)
6-5