11.4 DC braking
The "DC braking" funcon generates a braking torque by injecng a DC current into the motor.
The funcon can be used to shorten the braking of a load with high mass inera. Another
applicaon is holding the motor sha either before starng or while stopping.
NOTICE
Avoid long-me acvaon of the "DC braking" funcon with a high braking current or a high
braking voltage!
Possible consequence: thermal motor overload.
▶
Only use the "DC braking" funcon in applicaons in which the load is only exceponally
stopped.
▶
Do not acvate the "DC braking" funcon longer than necessary.
Precondions
The "DC braking" funcon is only possible if the inverter is enabled.
Details
The funcon can be used as follows:
1.
Automacally when the motor is started.
2.
Automacally when the motor is stopped.
3.
Manually (via the exible I/O conguraon).
The three opons can also be combined, for instance automac DC braking when starng and
stopping the motor.
For further details and conguraon examples, see the following chapter:
4Example 1: Automac DC braking when the motor is started ^ 270
4Example 2: Automac DC braking when the motor is stopped ^ 271
4Migraon of Lenze Inverter Drives 8200/8400 ^ 273
4Acvang DC braking manually ^ 386
Parameter Name / value range / [default seng] Info
0x2B84:001
(P704.01)
DC braking: Current
(DC braking: Current)
0.0 ... [0.0] ... 200.0 %
Braking current for DC braking.
•
100 % ≡ rated motor current 0x6075 (P323.00)
0x2B84:002
(P704.02)
DC braking: Automac hold me
(DC braking: Hold me autom.)
0.0 ... [0.0] ... 1000.0 s
Hold me for automac DC braking.
•
The "Automac DC braking" funcon is acve for the me set here.
•
1000.0 = innite
Note!
Do not set this parameter to the value "1000.0" (innite) if the DC brak-
ing is used during the start. The "Innite" seng can be used to lock the
rotor for an indenite me while a stop is acve. However, ensure here
that the longer DC braking does not cause a thermal overload of the
motor!
0x2B84:003
(P704.03)
DC braking: Automac operang threshold
(DC braking: Threshold autom.)
0.0 ... [0.0] ... 599.0 Hz
Operang threshold for automac DC braking.
•
With the seng 0, the "Automac DC braking" funcon is deacva-
ted.
0x2B84:004
(P704.04)
DC braking: Demagnezaon me
(DC braking: Demagnet. me)
0 ... [100] ... 150 %
•
From version 04.00
In the default seng, the DC braking is acvated aer the standard
demagnesing me has elapsed. This parameter can be used to adapt
the me.
•
100 % ≡ Default demagnezaon me 0x2B84:005 (P704.05)
Note!
A too short demagnesing me can cause an overcurrent error!
0x2B84:005
(P704.05)
DC braking: Default demagnezaon me
(DC braking: Def. demag. me)
•
Read only: x ms
•
From version 04.00
Display of the standard demagnesing me as a seng help for the user.
•
This me is calculated by the inverter:
Demagnesing me = 7 * rotor me constant
Addional funcons
DC braking
268