Toshiba H7 Operation Manuals page 117

F304
Dynamic Braking Enable
Program Protection Parameters
⇒
This parameter Enables/Disables the Dynamic Braking system if so equipped.
Settings:
Enabled with Overload
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 drive and providing the proper
information at F304, F308, and F309.
For additional information on selecting the proper resistance value for a given
application contact Toshiba's Marketing Department.
Note: The Dynamic Braking function is not available on the 230 volt - 30 and
40 HP, the 400 volt - 25 – 350 HP, and the 600 volt - 22 – 300 HP ASDs.
Overvoltage Stall
Program ⇒ Protection Parameters
This parameter Enables/Disables the Overvoltage Stall function. When
enabled, this function causes the drive to extend the decel time when the DC
bus voltage increases due to transient voltage spikes, regeneration, supply
voltage out of specification, etc. in an attempt to reduce the bus voltage.
Settings:
Enabled
Disabled
Enabled (Forced Shorted Deceleration)
Motor #1 Max Output Voltage
Program ⇒ Motor Parameters
This parameter sets the maximum value of the output voltage of the drive. The
Motor #1 Maximum Output Voltage is the Motor #1 output voltage at the
Base Frequency (F014). Regardless of the programmed value, the output
voltage cannot be higher than the input voltage.
The actual output voltage will be influenced by the input voltage of the ASD
and the Supply Voltage Compensation setting (F307).
110
Dynamic Braking
⇒
⇒ Stall
⇒ Motor Set #1
Direct Access Number — F304
Parameter Type — Selection List
Factory Default — Disabled
Changeable During Run — No
Direct Access Number — F305
Parameter Type — Selection List
Factory Default — Enabled
Changeable During Run — Yes
Direct Access Number — F306
Parameter Type — Numerical
Factory Default — (drive dependent)
Changeable During Run — Yes
Minimum — 0.0
Maximum — 600.0
Units — Volts
H7 ASD Operation Manual
F306