ABB ACS800 Firmware Manual page 178

178
Index Name/Selection
21.04 DC HOLD
NO
YES
21.05 DC HOLD SPEED
0 ... 3000 rpm
21.06 DC HOLD CURR
0 ... 100%
21.07 RUN ENABLE FUNC
RAMP STOP
COAST STOP
OFF2 STOP
OFF3 STOP
Actual signals and parameters
Description
Activates/deactivates the DC hold function. DC hold is not possible if
parameter 99.04 = SCALAR.
When both the reference and the speed drop below the value of parameter
21.05, the drive will stop generating sinusoidal current and start to inject DC
into the motor. The current is set with parameter 21.06. When the reference
speed exceeds parameter 21.05, normal drive operation continues.
SPEED
motor
Ref.
DC HOLD SPEED
Note: DC hold has no effect if the start signal is switched off.
Note: Injecting DC current into the motor causes the motor to heat up. In
applications where long DC hold times are required, externally ventilated
motors should be used. If the DC hold period is long, the DC hold cannot
prevent the motor shaft from rotating if a constant load is applied to the motor.
Inactive
Active
Defines the DC hold speed. See parameter 21.04.
Speed in rpm
Defines the DC hold current. See parameter 21.04.
Current in percent of the motor nominal current
Selects the stop mode applied when Run Enable signal is switched off. Run
Enable signal is put into use with parameter 16.01.
Note: In the Master/Follower mode, the settings must be the same in both the
Master and the Follower drives.
Note: The setting overrides the normal stop mode setting (parameter 21.03)
when Run Enable signal is switched off.
The application program stops the drive along the deceleration ramp defined in
group 22 ACCEL/DECEL.
The application program stops the drive by cutting off the motor power supply
(the inverter IGBTs are blocked). The motor rotates freely to zero speed.
WARNING! If the brake control function is on, the application program
uses ramp stop in spite of the selection COAST STOP (see parameter
group 42 BRAKE
The application program stops the drive by cutting off the motor power supply
(the inverter IGBTs are blocked). The motor rotates freely to zero speed. The
drive will restart only when the Run Enable signal is on and the start signal is
switched on (the program receives the rising edge of the start signal).
The application program stops the drive along the ramp defined with parameter
22.07. The drive will restart only when the Run Enable is on and the start signal
is switched on (the program receives the rising edge of the start signal).
DC hold
CONTROL).
FbEq
t
t
0
65535
0 ... 3000
0 ... 100
1
2
3
4