ABB ACS850 series, Firmware Manual

Page: 86 / 260

86 Parameters
Const time The drive pre-magnetizes the motor before start. The pre-
magnetizing time is defined by parameter
11.02 Dc-magn
time . This mode should be selected if constant pre-
magnetizing time is required (e.g. if the motor start must be
synchronized with the release of a mechanical brake). This
setting also guarantees the highest possible break-away
torque when the pre-magnetizing time is set long enough.
WARNING! The drive will start after the set
magnetizing time has passed even if motor
magnetization is not completed. In applications
where a full break-away torque is essential,
ensure that the constant magnetizing time is long enough to
allow generation of full magnetization and torque.
1
Automatic Automatic start guarantees optimal motor start in most cases.
It includes the flying start function (starting to a rotating
machine) 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.
Note: If parameter 99.05 Motor ctrl mode is set to Scalar , no
flying start or automatic restart is possible by default.
2
11.02 Dc-magn time Defines the constant DC magnetizing time. See parameter
11.01 Start mode . After the start command, the drive
automatically premagnetizes the motor the set time.
To ensure full magnetizing, set this value 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:
Note: This parameter cannot be changed while the drive is
running.
0 … 10000 ms Constant DC magnetizing time. 1 = 1 ms
11.03 Stop mode Selects the motor stop function.
Coast Stop by cutting of the motor power supply. The motor coasts
to a stop.
WARNING! If the mechanical brake is used,
ensure it is safe to stop the drive by coasting.
1
Ramp Stop along ramp. See parameter group 22 Speed ref ramp on
page 125 .
2
11.04 Dc hold speed Defines the DC hold speed. See parameter 11.06 Dc hold .
0.0 … 1000.0 rpm DC hold speed. 10 = 1 rpm
11.05 Dc hold curr ref Defines the DC hold current in percent of the motor nominal
current. See parameter
11.06 Dc hold .
0 … 100% DC hold current. 1 = 1%
No. Name/Value Description FbEq
Motor rated power Constant magnetizing time
< 1 kW > 50 to 100 ms
1 to 10 kW > 100 to 200 ms
10 to 200 kW > 200 to 1000 ms
200 to 1000 kW > 1000 to 2000 ms