Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX - Manual (Page 210)

11-12 Parameters
13 Bus/Brake Opts
Bus/Brake Opts lets you choose options for the bus filter
reference, precharge/ridethrough conditions, and braking.
Use bits 0 through 4 to set the slew rate for the bus voltage
tracker. The bus voltage tracker slowly tracks changes in the
actual bus voltage. If the actual bus voltage drops 150 volts or
more below the current value of the bus voltage tracker, the drive
automatically disables modulation and enters precharge. Bits 0
through 4 select the sensitivity of the bus voltage tracker to
changes in the actual bus voltage. If none of the bits (0 through
4) are set, the slew rate is 0.05V/second.
The precharge function of the drive limits the current to the bus
capacitors when power is initially applied to the drive. The
precharge function is completed after a minimum 300 millisecond
time delay and bus voltage at least 30 volts greater than the
undervoltage setpoint and a stable bus voltage. Ridethrough
provides extended logic operating time if the power lines drop out
while the drive is running. If the precharge function is enabled,
ridethrough also provides inrush current protection by starting a
precharge, in case the incoming power returns.
The bits are defined as follows:
Parameter number 13
File:group Application:Flux Braking
Application:DC Braking/Hold
Application:Fast Flux Up
Application:Bus Reg/Control
Parameter type linkable destination
Display bits
Factory default 00000000.00000000
Minimum value 00000000.00000000
Maximum value 11111111.11111111
Conversion 1 = 1
For additional information about Bus/Brake Opts, refer to
Chapter 9, Applications and Chapter 12, Troubleshooting.
Important: If you add a dynamic brake after completing the drive
start up, you must run start up again or manually adjust Regen
Power Lim (parameter 76) to the proper value. If you do not, the
drive will be limited to 25% regen.
Bit Description
0 Slew Rate 1
Set to choose a slew rate of 10V/second.
1 Slew Rate 2
Set to choose a slew rate of 5V/second.
2 Slew Rate 3
Set to choose a slew rate of 0.5V/second.
3 Slew Rate 4
Set to choose a slew rate of 0.05V/second.
4 Slew Rate 5
Set to choose a slew rate of 0.005V/second.
5 Bus High Lim
Set this bit only when bit 10 is set and the brake used
on the drive is undersized. Refer to Chapter 9,
Applications.
6 Flux Braking
Set to use an increase in the motor flux current to
increase the motor losses and allow a faster
deceleration time when there is no chopper brake or
regenerative capability.
7 DC Hold
Set to enable DC hold. This applies DC current to the
motor to attempt to hold zero speed in encoderless
operation when the drive is stopped.
Bit Description
8 Fast Fluxup
Set to enable fast flux up. Fast Flux Level
(parameter 78) set the level of current used to build flux
in the motor.
9 DC Braking
Set to apply DC current to the motor when a stop is
commanded. DC Brake Current (parameter 79) sets the
level, and DC Brake Time (parameter 80) sets the time
10 Brake/Regen
Set to indicate that a chopper brake, common bus, or
regenerative capability is present.
0 = The bus voltage controller is on.
1 = The bus voltage controller is off unless bit 5 is set
(1). Refer to Chapter 9, Applications.
11 Prech Exit
Set to force an exit from precharge after the precharge
timeout.
12 En Comm Bus
Set to enable common bus precharge. External fault
input is used as precharge enable.
13 Dis Prech Tm
Set to disable bus precharge and undervoltage faults
while the drive is disabled.
14 Dis Mult Pre
Set to disable all precharges after the first power up.
15 Dis Ridethru
Set to disable all ridethroughs.