WEG CFW700, Programming And Troubleshooting Manual

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Dynamic Braking
14
CFW700 | 14-1
14 DYNAMIC BRAKING
The braking torque that can be obtained through the application of frequency inverters without dynamic braking
resistors varies from 10 % to 35 % of the motor rated torque.
In order to obtain higher braking torques, resistors for dynamic braking are used. In this case the regenerated
energy is dissipated on the resistor mounted externally to the inverter.
This type of braking is used in the cases when short deceleration times are wished or when high inertia loads
are driven.
For the vector control mode there is the possibility of the use of the “Optimal Braking”, eliminating in many cases
the need of the dynamic braking.
The Dynamic Braking function can only be used if a braking resistor has been connected to the CFW700, and if
the parameters related to it have been adjusted properly.
See next the description of the parameters in order to know how to program each one.
P0153 – Dynamic Braking Level
Adjustable
Range:
339 to 400 V
585 to 800 V
585 to 800 V
585 to 800 V
585 to 800 V
Factory
Setting:
P0296=0: 375 V
P0296=1: 618 V
P0296=2: 675 V
P0296=3: 748 V
P0296=4: 780 V
Properties:
Access groups
via HMI:
Description:
The parameter P0153 defines the voltage level for the braking IGBT actuation, and it must be compatible with
the power supply voltage.
If P0153 is adjusted at a level very close to the overvoltage (F022) actuation level, the fault may occur before the
braking resistor is able to dissipate the regenerated energy.
The next table presents the overvoltage trip level.
Table 14.1: Overvoltage (F022) trip levels
Inverter V
nom
P0296 F022
220/230 V 0 > 400 V
380 V 1
> 800 V
400/415 V 2
440/460 V 3
480 V 4