09.02  Connection 
Siemens AG    6SE7087-6AK85-1AA0 
3-3 
Rectifier/Regenerating Unit    Operating instructions 
WARNING 
 
The operating coils of contactors and relays that are connected to the same supply 
network as the unit or that are located in close proximity of the unit must be connected to 
overvoltage limiters, e.g. RC circuits. 
An RCCB (residual-current-operated circuit-breaker) must not be used to protect the 
rectifier/regenerating unit (DIN VDE 0160). 
Voltage is only permitted to be applied to the unit when SIMOVERT Master Drives are 
connected. Operation without a connected DC link capacitor is not permitted! 
If the DC link terminals are connected incorrectly or short-circuited, the SIMOVERT Master 
Drives inverter will be destroyed! 
To reduce mains pollution, limit harmonics and reduce current ripple, the total system 
inductance for the supply and feedback connection (incl. commutating reactor and, where 
applicable, autotransformer must result in a total relative short-circuit voltage u
k
 between 
4% and 10%. 
Connect the fan power supply to X19. 
The fan continues to run for about four minutes or until a certain cooling element 
temperature threshold is undershot (provided its power supply is connected) after the unit 
has been switched off, following fault messages, on canceling the enable signal and after 
isolating the system supply connection. 
Despite switching the voltage off at the power terminals, a voltage may still exist on 
terminal X19 due to the external fan supply. 
NOTES 
The supply voltages applied to the rectifier and regenerating power terminals (U1/L1, V1/L2, W1/L3 and 
1U2/1T1, 1V2/1T2, 1W2/1T3) must have an identical phase angle
 and identical frequency. 
Recommendation:
 The inductive components of the impedance drop u
k
 of the (auto) transformer should lie 
between 1.5 and 3% (see Table 3.4). 
Commutating reactor:
 Selection of the reactors for 4 % u
k
 should be based on the rated current in 
regenerative mode on the line side (see Technical Data). In weak or low-power systems, the u
k
 of 
the commutating reactor must be decreased in order not to exceed the upper limit for the total u
k
 of 
10%. A further measure in the case of extremely high u
k
 values for the supply network can be 
implemented by connecting the primary side of the autotransformer to the supply network directly 
(before the commutating reactors), to ensure that the total u
k
 value in the regenerating direction will 
not be too high. 
Rectification
Regeneration
DC link
Mains
Arrangement for high-power system Arrangement for low-power system
Rectification
Regeneration
DC link
Mains
 
 
    For the selection of the commutating reactors, see Table 3.6 and Catalog DA93.1. 
With an extremely high total u
k
 value in the regenerative direction, it may be necessary due to the 
increased thyristor current commutating time, to reduce the inverter step limit (parameter P776). This 
may mean it is necessary to reduce Ud. 
Output reactors in the DC circuit
 are not permitted (even with the parallel connection of power sections or 
in 12-pulse mode), because the DC link voltage is measured at the unit output terminals.  
 
AoteWell Automation Sales Team
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