Siemens SINAMICS G130 Engineering Manual page 132

Fundamental Principles and System Description
Engineering Information
The amplitude of these additional current peaks is in proportion to the cable capacitance, i.e. the cable length, and in
proportion to the voltage rate-of-rise dv/dt at the converter output in accordance with the relation
Although the additional current peaks occur within a period of only a few ms, the inverter must be able to provide them
for this short period in addition to the motor current. The inverter is capable of providing the peak currents up to a
specific limit of the motor cable capacitance. However, if this limit is exceeded because the motor cables are too long
or too many of them are connected in parallel, the inverter will shut down with error message "Overcurrent".
At the drive configuration stage, therefore, it is important to observe the motor cable lengths and cross-sections
specified for individual inverter units. Alternatively, additional measures have to be taken to allow the connection of
greater cable lengths and cross-sections.
For basic configurations, i.e. without motor reactors, dv/dt filters plus VPL, dv/dt filters compact plus VPL or sine-
wave filters at the inverter output, the permissible motor cable lengths which apply as standard to SINAMICS G130,
G150, S150, S120 Motor Modules (Chassis and Cabinet Modules) are listed in the table below:
Line supply voltage
380 V – 480 V 3AC
500 V – 600 V 3AC
660 V – 690 V 3AC
Permissible motor cable lengths for basic configurations of SINAMICS G130 Chassis, SINAMICS G150 and S150 cabinets
and SINAMICS S120 Motor Modules in the Chassis and Cabinet Modules format
Note:
The specified motor cable lengths always refer to the distance between inverter output and motor along the cable
route and already allow for the fact that several cables must be routed in parallel for drives in the higher power range.
The recommended and the maximum connectable cross-sections plus the permissible number of parallel motor
cables are unit-specific values. These values can be found in the unit-specific chapters of this engineering manual or
in the relevant catalogs. Where more than one motor cable is routed in parallel, please note that each individual
motor cable must contain all three conductors of the three-phase system. This helps to minimize the magnetic
leakage fields and thus also the magnetic interference on other loads. The diagram below shows an example of three
motor cables routed in parallel.
~
L1
L2
~
L3
Symmetrical connection to the converter and motor of several motor cables routed in parallel
Example:
In the case of the SINAMICS G150 cabinet, 380 V to 480 V, 560 kW, Catalog D 11 recommends the routing of four
parallel cables with a cross-section each of 185 mm
converter output and motor can be positioned at a distance of 300 m along the cable route when shielded cables are
used. With this constellation, therefore, 4
the maximum permissible cable distance of 300 m between the inverter and motor.
If the specified motor cable lengths are not sufficient for some special drive constellations, suitable measures must be
taken to allow the use of greater motor cable lengths and cross-sections. This can be achieved, for example, by using
appropriately dimensioned motor reactors which attenuate the additional current peaks and allow the connection of a
higher motor cable capacitance (see section "Motor reactors").
SINAMICS Engineering Manual – November 2015
132/528
Ó Siemens AG
I = C
c Cable Cable *
Max. permissible motor cable lengths for basic configurations
Shielded cable
e.g. Protodur NYCWY
1
2
3
1
2
3
1
2
3
2
for the motor connection. According to the table above,
300 m = 1200 m of cable would need to be installed in order to implement
*
dv/dt .
300 m
300 m
300 m
1
2
L1
3
M
1
2 L2
3
1 L3
2
3
Unshielded cable
e.g. Protodur NYY
450 m
450 m
450 m