Emotron VS10 - DC Braking

278 01-6203-01R3, CG Drives & Automation
10.4. DC braking
The "DC braking" function generates a braking torque by injecting a DC current into the
motor. The function can be used to shorten the braking of a load with high mass inertia.
Another application is holding the motor shaft either before starting or while stopping.
NOTICE
Avoid long-time activation of the "DC braking" function with a high braking current or a
high braking voltage!
Possible consequence: thermal motor overload.
▶ Only use the "DC braking" function in applications in which the load is only exceptionally stopped.
▶ Do not activate the "DC braking" function longer than necessary.
Preconditions
The "DC braking" function is only possible if the inverter is enabled.
Details
The function can be used as follows:
1. Automatically when the motor is started.
2. Automatically when the motor is stopped.
3. Manually (via the flexible I/O configuration).
The three options can also be combined, for instance automatic DC braking when starting
and stopping the motor.
For further details and configuration examples, see the following chapter:
Example 1: Automatic DC braking when the motor is started  264
Example 2: Automatic DC braking when the motor is stopped  265
Activating DC braking manually  400
Parameter
Name / value range / [default setting]
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: Automatic hold time
(DC braking: Hold time autom.)
0.0 ... [0.0] ... 1000.0 s
Hold time for automatic DC braking.
The "Automatic DC braking" function is active for the time set here.
1000.0 = infinite
Note!
Do not set this parameter to the value "1000.0" (infinite) if the DC
braking is used during the start. The "Infinite" setting can be used to
lock the rotor for an indefinite time while a stop is active. However,
ensure here that the longer DC braking does not cause a thermal
overload of the motor!
0x2B84:003
(P704.03)
DC braking: Automatic operating threshold
(DC braking: Threshold autom.)
0.0 ... [0.0] ... 599.0 Hz
Operating threshold for automatic DC braking.
With the setting 0, the "Automatic DC braking" function is
deactiva
ted.
0x2B84:004
(P704.04)
DC braking: Demagnetization time
(DC braking: Demagnet. time)
0 ... [100] ... 150 %
From version 04.00
In the default setting, the DC braking is activated after the standard
demagnetising time has elapsed. This parameter can be used to adapt
the time.
100 % ≡ Default demagnetization time 0x2B84:005 (P704.05)
Note!
A too short demagnetising time can cause an overcurrent error!
0x2B84:005
(P704.05)
DC braking: Default demagnetization time
(DC braking: Def. demag. time)
Read only: x ms
From version 04.00
Display of the standard demagnetising time as a setting help for the
user.
This time is calculated by the inverter:
Demagnetising time = 7 * rotor time constant