Emc-Compliant Connection - Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual

3.3.4

EMC-compliant connection

The inverters are designed for operation in industrial environments where high values of
electromagnetic interference are expected. Safe, reliable and disturbance-free operation is
only guaranteed if the devices are professionally installed.
Inverters with degree of protection IP20 must be installed and operated in an enclosed
control cabinet.
Control cabinet design
● All metal parts and components of the control cabinet (side panels, rear panels, roof and
● The PE bar and the EMC shield bar must be connected to the control cabinet frame
● All of the metal enclosures of the devices and supplementary components installed in the
● All of the connections must be implemented so that they are durable. Screw connections
● Coils of contactors, relays, solenoid valves and motor holding brakes must be equipped
Cable routing and shielding
● All inverter power cables (line supply cables, connecting cables between the braking
● The cables from the line supply to the line filter must be routed separately away from non-
● Signal and data cables as well as filtered line supply cables may only cross non-filtered
● All cables should be kept as short as possible
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
base plates) must be connected to the control cabinet frame through a good electrical
connection – this is best achieved using the highest possible surface area or a high
number of individual screw connections
through a good electrical connection established through a large surface area.
cabinet – e.g. inverter or line filter – must be connected to the control cabinet frame
through a good electrical connection through the largest possible surface area. The most
favorable design is to mount these devices and supplementary components on a bare
metal mounting plate with good conducting characteristics; this in turn is connected to the
control cabinet frame through a good electrical connection and the largest possible
surface area. It is especially important that they are connected to the PE and EMC shield
bars.
to painted or anodized metal components must either be established using special
contact (serrated) washers that cut through the insulating surface and therefore establish
a metallic conductor contact, or the insulating surface must be removed at the contact
locations.
with interference suppression elements in order to dampen high-frequency radiation
when switching-off (RC elements or varistors with AC coils and free-wheeling diodes or
varistors for DC coils). The protective circuit must be directly connected at the coil.
chopper and the associated braking resistance as well as the motor cables) must be
separately routed away from signal and data cables. The minimum clearance should be
approx. 25 cm. As an alternative, the decoupling can be realized in the control cabinet
using metal partitions (separating elements) connected to the mounting plate through a
good electrical connection
filtered power cables with a high noise level (cables between the line filter and inverter,
connecting cables between the braking chopper and the associated braking resistor as
well as motor cables)
power cables at right angles
Installing
3.3 Installing Power Module
39