Operating instructions

Operation with only one supply frequency inverter
MICROMASTER 420 / 440 – DC link coupling between several
Frequency inverters
5 Operation with up to three supply inverters
If several drives predominantly operate in the motoring mode in a DC link
group, then one supply inverter is no longer sufficient. In this case up to
three frequency inverters can be connected to the line supply and coupled
through the DC link. Additional frequency inverters can be connected to this
DC link group and supplied.
Line fuses
Line reactors /
DC link fuses
Inverter
M
3 ~
Motor
M
3 ~
M
3 ~
Motor Motor
MM440
22kW
MM440
15kW
MM420
11kW
Braking resistor
3-ph. 200-240V AC 50/60Hz
3-ph. 380-480V AC 50/60Hz
PE PE PE
PEPEPE
M
3 ~
M
3 ~
Motor Motor
MM440
1,5kW
MM420
1,5kW
PE PE
PEPE
Line
contactor
L1
L2
L3
PE
Copyright © Siemens AG 2005 All rights reserved
Fig. 3-1: Block circuit diagram of a DC link coupling with three supply inverters,
example for operation with a three-phase line supply
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