Siemens Simovert Masterdrives Compendium page 1026

When using the reduced voltage mode, pay attention to the following:
If the DC link voltage V rises from the reduced range to the chopper switch-in threshold in
dc_link
less than 3 s (as a result of heavy braking), proper functioning of the chopper cannot be assured.
The chopper can possibly fail to turn on, which will cause the converter or inverter to cut out as a
result of fault F006 "Overvoltage".
Caution: The DC link voltage may never be suddenly increased again.
DC link voltage
r006
DC link voltage
of [500.4] V (act)
dc_link
1 2
DC link voltage reduction
Reduced V
dc_link,MAX
10 ... 510 V
V > Reduced V
dc_link
U837.2 (380 V)
Reduced V
dc_link,MIN
10 ... 510 V
V
dc_link
U837.1 (380 V)
Q.Sel.red.V
0,76 x V
dc_link
3 4
dc_link_max
V within reduced voltage mode limits
dc_link
< Reduced V
dc_link,MIN
dc_link
U838 (0)
B
0
(nom.)
1
5
V2.5
fp_mc_501_e.vsd
U > Reduced V
dc_link dc_link,MAX
B0858
V < Reduced V
dc_link dc_link,MIN
B0859
Emerg/Reduced voltage mode
B0856
F002 Precharging fault
F008 DC_link Undervoltage
6 7
Function diagram
MASTERDRIVES MC
08.01.02
n957.83 = 4
8
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