Dynamic Braking; Over-Voltage Limit Operation - Toshiba H9 ASD Installation And Operation Manual

F304

Dynamic Braking

Program Protection Dynamic Braking
This parameter Enables/Disables the Dynamic Braking system.
Settings:
0 — Off
1 — On with Overload Detection
2 — On without Overload Detection
Dynamic Braking uses the transistor IGBT7 to dissipate the bus voltage when
required.
IGBT7 is a standard item on the 25 HP and below H9 ASD 230-volt systems
and is standard on the 400 HP and below for the for the 460-volt systems.
IGBT7 is optional for all remaining systems.
Dynamic Braking
Dynamic Braking is used to prevent over-voltage faults during rapid
deceleration or constant speed run on cyclic overhauling applications.
Dynamic Braking dissipates regenerated energy in the form of heat. When
using a DBR use thermal protection.
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.
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.
See the section titled
more information on using the DBR system and for assistance in selecting the
appropriate resistor for a given application.

Over-Voltage Limit Operation

Program Protection Stall
This parameter enables the Over-Voltage Limit function. This feature is used
to set the upper DC bus voltage threshold that, once exceeded, will cause an
Over-Voltage Stall.
An Over-Voltage Stall increases the output frequency of the drive during
deceleration for a specified time in an attempt to prevent an Over-Voltage Trip.
If the over-voltage threshold level setting of parameter
over 4 mS, an Over-Voltage Trip will be incurred.
Note: This parameter setting may increase deceleration times.
Settings:
0 — Enabled (Over-voltage Stall)
1 — Disabled
2 — Enabled (Forced Shorted Deceleration)
3 — Enabled (Forced Dynamic Braking Deceleration)
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Dynamic Braking System Specifications on pg. 266
Direct Access Number — F304
Parameter Type — Selection List
Factory Default — Off
Changeable During Run — No
for
Direct Access Number — F305
Parameter Type — Selection List
Factory Default — (ASD-Dependent)
Changeable During Run — Yes
F626 is exceeded for
H9 ASD Installation and Operation Manual
F305