136
H9 ASD Installation and Operation Manual
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
Dynamic Braking System Specifications on pg. 266
for
more information on using the DBR system and for assistance in selecting the
appropriate resistor for a given application.
Direct Access Number — F304
Parameter Type —
Selection List
Factory Default —
Off
Changeable During Run —
No
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
F626
is exceeded for
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)
Direct Access Number — F305
Parameter Type —
Selection List
Factory Default —
(ASD-Dependent)
Changeable During Run —
Yes
F304
F305
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