Lenze 8400 BaseLine D - Manual (Page 102)

5 Motor control (MCTRL)
5.7 Braking operation/braking energy management
102
Lenze · 8400 BaseLine D · Reference manual · DMS 5.5 EN · 01/2014 · TD05
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5.7 Braking operation/braking energy management
When electric motors are braked, the kinetic energy of the drive train is fed back into the DC circuit
regeneratively. This energy leads to an increase in the DC bus voltage. In order to avoid overvoltage
in the DC bus, several different strategies can be used:
• Use of an external brake resistor
• Use of an external brake module
(only for inverters with single phase supply)
• Coupling of the inverters in a DC-bus connection
(only for inverters with three-phase supply)
• Recovery of regenerative energy with a regenerative module
(only for inverters with three-phase supply)
Short overview of the relevant parameters:

Stop!
If the connected brake resistor is smaller than required, the brake chopper can be de-
stroyed!
• For rated data see hardware manual.
• Appropriate protective measures are provided in the "
Avoiding thermal overload of
the brake resistor " subchapter. ( 103)

Note!
• We recommend to use the brake chopper (brake transistor) which is integrated into
the controller for the braking operation, regardless of the selected motor control.
• For a DC-bus connection with other devices, we recommend to connect the regenera-
tive power supply module to terminals +UG and –UG.
• If none of these measures is taken, e.g. the overvoltage deactivation ("OU") may re-
spond in case of low deceleration times during regenerative operation.  Error
messages of the operating system ( 153)

Observe the notes on braking operation in the hardware manual!
(see "braking operation" chapter).
All the necessary instructions for the drive controller are stored in electronic form on the
data carrier supplied with the 8400 drive controller.
Parameter Info Lenze setting
Value Unit
C173 Mains voltage 3ph 400 V / 1ph 230 V
C174 Reduced brake chopper threshold 0 V
C574 Resp. to brake resist. overtemp. No response