Siemens SINAMICS DCM Manual page 96

The figure below shows how the four categories are assigned to the first and second
environments:
Figure 6-2
SINAMICS DC MASTER devices are nearly always used in the second environment
(categories C3 and C4).
RFI suppression filters and line reactors are required whenever they are to be used in
Category C2.
The SINAMICS DC MASTER conform to the interference immunity requirements defined in
EN 61800-3 for the second environment, and thus also with the lower interference immunity
requirements for the first environment.
SINAMICS DC MASTER: Industrial applications
Industrial applications demand that devices demonstrate an extremely high level of
interference immunity, but by contrast place very low requirements on them in terms of
interference emission levels.
SINAMICS DC MASTER converters are components of an electrical drive, such as
contactors and switches. Qualified personnel must install them into a drive system which, as
an absolute minimum, consists of the converter, motor cables, and motor. Line reactors and
fuses are also required in most cases. Therefore, whether or not a limit value is adhered to is
determined by the components being installed correctly. In order to limit the interference
emission in compliance with the limit value for category C2 according to EN61800-3, RFI
suppression filters are required in the mains supply conductors for the armature and field
power units and the line reactors. Without RFI suppression filters, the interference emission
of SINAMICS DC MASTER converters exceeds the limit value for category C2.
If the drive forms part of a system, it does not initially need to fulfill any interference emission
requirements, but the EMC Directive does require the system as a whole to be
electromagnetically compatible with its environment.
Non-grounded networks
Non-grounded networks (IT systems) are used in some branches of industry in order to
increase the availability of the plant. In the event of a ground fault, no fault current flows and
the plant can continue with production. If RFI suppression filters are brought into the
equation, however, a fault current does flow in the event of a ground fault, which may cause
the drives to shut down or the RFI suppression filter to potentially be destroyed. For this
reason, the product standard does not define any limit values for these networks. From an
economical perspective, any necessary EMC conformance measures should be taken on the
grounded primary side of the supply transformer.
SINAMICS DCM DC Converter
Operating Instructions, 02.2015, A5E34763375/RS-AA/001
Definition of categories C1 to C4
ac.maher.co.ir
6.1 Instructions for EMC-compliant drive installation
Connecting
97