Proper Emc Installation Of Drives (Installation Instructions); General; Rules For Proper Emc Installation - Siemens SIMOTRAS 6SG7050 Operating Instructions Manual

Connections
6.2.2

Proper EMC installation of drives (installation instructions)

6.2.2.1

General

Since drives can be operated in a wide range of differing environments and the electrical
components used (controls, switched-mode power supplies, etc.) can differ widely with respect to
noise immunity and radiation, any mounting/installation guideline can only represent a practical
compromise. For this reason, EMC regulations do not need to be implemented to the letter,
provided that measures are checked out on a case by case basis.
In order to guarantee electromagnetic compatibility in your cabinets in rugged electrical
environments and fulfil the standards specified by the relevant regulatory bodies, the following EMC
regulations must be observed when designing and installing cabinets.
Rules 1 to 10 generally apply. Rules 11 to 15 must be followed to fulfil standards governing radiated
noise.
6.2.2.2

Rules for proper EMC installation

Rule 1
All the metal components in the cabinet must be conductively connected over a large surface area
with one another (not paint on paint!). Serrated or contact washers must be used where necessary.
The cabinet door should be connected to the cabinet through the shortest possible grounding straps
(top, center, bottom)..
Rule 2
Contactors, relays, solenoid valves, electromechanical hours counters, etc. in the cabinet, and, if
applicable, in adjacent cabinets, must be provided with quenching elements, for example, RC
elements, varistors, diodes. These devices must be connected directly at the coil.
Rule 3
Signal cables
Rule 4
Unshielded cables in the same circuit (incoming and outgoing conductors) must be twisted where
possible, or the area between them kept as small as possible in order to prevent unnecessary
coupling effects.
Rule 5
Connect spare conductors to the cabinet ground (ground
shielding effect.
Rule 6
Avoid any unnecessary cable lengths in order to reduce coupling capacitances and inductances.
Rule 7
Crosstalk is kept low if cables are routed close to the cabinet ground. For this reason, wiring should
not be routed freely in the cabinet, but as close as possible to the cabinet frame and mounting
panels. This applies equally to spare cables.
Rule 8
Signal and power cables must be routed separately from one another (to prevent noise from being
coupled in). A minimum 20 cm clearance should be maintained.
If the encoder cables and motor cables cannot be routed separately, then the encoder cable must
be decoupled by means of a metal partition or installation in a metal pipe or duct. The partition or
metal duct must be grounded at several points.
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.
6-8
1)
should enter the cabinet at only one level wherever possible.
2)
) at both ends to obtain an additional
SIEMENS AG
SIMOTRAS HD
01.04
2)
)
6SG7000-0BA76
Operating Instructions