ABB ACS880 - Page 291

Def / Type
FbEq 16b / 32b
DescriptionName / Range /
Selection
No.
2Automatic start guarantees optimal motor start in
most cases.
It includes the flying start function (starting into a
rotating motor) and the automatic restart function (a
stopped motor can be restarted immediately without
waiting the motor flux to die away). The drive motor
control program identifies the flux as well as the
mechanical state of the motor and starts the motor
instantly under all conditions.
Automatic
3This method is intended for asynchronous motors only,
and is optimized for applications where the drive must
be started into a rotating motor at high frequencies
(above 150 Hz).
Flying start
500 ms / uint16Defines the pre-magnetization time when
• parameter 21.1 Start mode is set to Constant time
(in DTC motor control mode), or
• parameter 21.19 Scalar start mode is set to Const
time (in scalar motor control mode).
After the start command, the drive automatically
premagnetizes the motor for the set time. To ensure
full magnetizing, set this parameter to the same value
as, or higher than, the rotor time constant. If not
known, use the rule-of-thumb value given in the table
below:
Constant magnetizing timeMotor rated power
≥ 50 to 100 ms< 1 kW
≥ 100 to 200 ms1 to 10 kW
≥ 200 to 1000 ms10 to 200 kW
≥ 1000 to 2000 ms200 to 1000 kW
Note: This parameter cannot be changed while the
drive is running.
Magnetization time21.2
1 = 1 ms / 1 = 1 msConstant DC magnetizing time.0...10000 ms
Coast / uint16Selects the way the motor is stopped when a stop
command is received.
Additional braking is possible by selecting flux braking
(see parameter 97.5 Flux braking).
Note: This parameter has no effect in a follower drive
in a master/follower configuration.
Stop mode21.3
0Stop by switching off the output semiconductors of
the drive.
The motor coasts to a stop.
WARNING!
If a mechanical brake is used, ensure it is safe
to stop the drive by coasting.
Coast
1Stop along the active deceleration ramp. See parameter
group 23 Speed reference ramp (page 311).
Ramp
Parameters 291