ABB ACS280, Firmware Manual, Page: 52 / 430

52 Program features
Settings and diagnostics
Parameters 21.08 DC current control (page 140 ), 21.09 DC hold speed (page 140 )
and
21.10 DC current reference
(page
140
).
Events: -
Post-magnetization
The function keeps the motor magnetized for a certain period after stopping.
This is to prevent the machinery from moving under load, for example before a
mechanical brake can be applied. Post-magnetization is activated by parameter
21.08 . The magnetization current is set by parameter 21.10 .
Note: Post-magnetization is only available when ramping is the selected stop
mode.
Settings and diagnostics
Parameters
21.01 Start mode
(page
136
),
21.02 Magnetization time
(page
137
),
21.03 Stop mode (page 137 ), 21.08 DC current control (page 140 ), 21.09 DC hold
speed
(page
140
) and
21.11 Post magnetization time
(page
140
).
Events: -
Pre-heating (Motor heating)
The pre-heating function keeps the motor warm and prevents condensation
inside the motor by feeding it with DC current when the drive has been stopped.
The heating can only be activated when the drive is in the stopped state, and
starting the drive stops the heating.
When pre-heating is activated and the stop command is given, pre-heating
starts immediately if the drive is running below the zero speed limit (see bit 0 in
parameter
06.19 Speed control status word
). If the drive is running above the
zero speed limit, pre-heating is delayed by the time defined by parameter 21.15
Pre-heating time delay
to prevent excessive current.
The function can be defined to be always active when the drive is stopped or it
can be activated by a digital input, fieldbus or supervision function. For
example, with the help of signal supervision function, the heating can be
activated by a thermal measurement signal from the motor.
The pre-heating current fed to the motor can be defined as 0…30% of the
nominal motor current.
Notes :
• In applications where the motor keeps rotating for a long time after the
modulation is stopped, it is recommended to use ramp stop with pre-
heating to prevent a sudden pull at the rotor when the pre-heating is
activated.