Lenze 8400 - Manual (Page 273)

Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
273
5 Motor control (MCTRL)
5.13 Braking operation/brake energy management
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Example:
• A 400 V device has a maximum mains voltage of 420 V AC.
• Maximum stationary DC-bus voltage: 420 V AC * 1.414 = 594 V DC
•
C00173 has been set with the selection "0" for 400 V AC mains.
• This means that C00174 can be set to a maximum of 131 V DC (725 V DC - 594 V DC).
5.13.2 Selecting the response to an increase of the DC-bus voltage
If the brake chopper threshold resulting from C00173 and C00174 is exceeded in the DC bus, the
reaction selected in C00175 takes place (use of the brake resistor and/or stop of the ramp function
generator and/or inverter-motor brake).
• Optimum following of the actual speed value until the speed setpoint is reached (e.g. the motor
is stopped rapidly) is always achieved with the help of a brake resistor
• Stopping the ramp function generator enables smoother deceleration with lower torque
oscillation..
• The inverter motor brake is available for selection in C00175 . This function enables rapid
braking without a brake resistor. Torque oscillations can occur due to the traversing
dynamics.  Inverter motor brake ( 275)

Stop!
• The two braking procedures "Stopping of the ramp function generator" and "Inverter
motor brake" can only be used for speed-controlled applications without the
influence of a position controller!
• When the "inverter motor brake" function is used, the Motor load monitoring (I2xt) is
not adapted. If it is braked too frequently, there is a risk of the motor being thermally
overloaded or the motor overload monitoring does not work properly!
• The "inverter motor brake" function must not be used with vertical conveyors (hoists)
or with active loads!