06.2005
Engineering Information
Siemens AG
6SE7087-6QX70 (Version AE)
SIMOVERT MASTERDRIVES
Compendium Motion Control
11-23
Line switches are used to disconnect the voltage on converters or
rectifier units. Depending on the customer's requirements, line switches
can be executed as main and emergency OFF switches (for installing in
doors), as load disconnectors with and without fuses, or as fuse switch
disconnectors.
The converter or the rectifier unit can be disconnected from the voltage
supply in the event of a fault by means of the line contactor or also via
the OFF command. The use of a line contactor prevents other
components, for example, pre-charging resistors, braking resistors,
from being damaged if there is a fault.
A line reactor reduces the harmonics of the system on the one hand
and protects the DC link capacitors from excessive current spikes on
the other. A line reactor with 2 % u
k
is necessary from a ratio:
System fault power > 33 x rated converter output
or if a rectifier unit is used together with inverters:
System fault power > 33 x total rated inverter outputs
Line filters are necessary if a certain radio interference level in
accordance with EN 55011 has to be maintained (class A1 for chassis
type units and B1 for Compact and Compact PLUS type units). The A1
or B1 radio interference level can only be maintained in conjunction
with a 2 % u
k
line reactor and shielded motor cables. On the Compact
PLUS type unit, the line reactor is contained in the line filter.
It is
not
permissible to use output reactors, sinusoidal filters and dv/dt
filters in the case of MASTERDRIVES Motion Control.
Line switches
Line contactor
Line reactor
Line filters
Output reactors,
sinusoidal filters,
dv/dt filters
