Toshiba W7 - Manual (Page 74)

68 W7 ASD Installation and Operation Manual
Dynamic Braking Enable
Program ⇒ Protection Settings ⇒ Dynamic Braking Enable
This parameter Enables/Disables the Dynamic Braking system.
Settings:
Enabled
Disabled
Dynamic Braking
Dynamic Braking uses the inertial energy of the load to produce a braking
force or it may be used to reduce the bus voltage in an attempt to preclude an
overvoltage trip during deceleration. The inertial energy of the load drives the
rotor and induces a current into the stator of the motor.
The induced stator current (energy) is dissipated through a resistive load. The
resistive load is connected across terminals PA and PB (non-polarized). Using a
low-value, high-wattage resistance as a load for the generated current, the
resistive load dissipates the induced energy. The dissipated energy is the energy
that would otherwise have caused the rotor to continue to rotate.
Dynamic Braking helps to slow the load quickly; it cannot act as a holding
brake.
The Dynamic Braking function may be setup and enabled by connecting a
braking resistor from terminal PA to PB of the ASD and providing the proper
information at the DBR parameters: Dynamic Braking Resistor (DBR)
Capacity, Dynamic Braking Resistance, and DC Injection Braking Current.
For additional information on selecting the proper resistance value for a given
application contact Toshiba’s Marketing Department.
Parameter Type — Selection List
Factory Default — Disabled
Changeable During Run — No
Dynamic Braking Resistance
Program ⇒ Protection Settings ⇒ Dynamic Braking Resistance
This parameter is used to input the resistive value of the Dynamic Braking
Resistor.
Note: Using a resistor value that is too low may result in system
damage.
Parameter Type — Numerical
Factory Default — (ASD-dependent)
Changeable During Run — No
Minimum — 1.0
Maximum — 1000.0
Units — Ω
Dynamic Braking Resistance Capacity
Program ⇒ Protection Settings ⇒ Dynamic Braking Resistance
Capacity
This parameter is used to input the wattage of the Dynamic Braking Resistor.
For additional information on selecting the proper resistor wattage value for a
given application contact Toshiba’s Marketing Department.
Note: Using a resistor with a wattage rating that is too low may
result in system damage.
Parameter Type — Numerical
Factory Default — (ASD-dependent)
Changeable During Run — No
Minimum — 0.01
Maximum — 600.0
Units — kW
Dynamic Braking Enable Dynamic Braking Resistance Capacity