ABB ACS560, Firmware Manual

Page: 72 / 514

72 Program features
The function can be defined to be always active when the drive is stopped or it can be
activated by a digital input, fieldbus, timed function 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.
• The heating function requires that the STO circuit is closed or not triggered open.
• The heating function requires that the drive is not faulted.
• Pre-heating uses DC hold to produce current.
Settings
Parameters 21.14 Pre-heating input source and 21.16 Pre-heating current (page 213 )

Energy optimization
The energy optimization function optimizes the motor flux so that total energy
consumption and motor noise level are reduced when the drive operates below the
nominal load. The total efficiency (motor and drive) can be improved by 1…20%
depending on load torque and speed.
Settings
• Menu  Energy efficiency
• Parameter 45.11 Energy optimizer (page 317 )

Switching frequency
The drive has two switching frequencies: reference switching frequency and
minimum switching frequency. The drive tries to keep the highest allowed switching
frequency (= reference switching frequency) if thermally possible, and then adjusts
dynamically between the reference and minimum switching frequencies depending
on the drive temperature. When the drive reaches the minimum switching frequency
(= lowest allowed switching frequency), it starts to limit output current as the heating
up continues.
For derating, see chapter Technical data , section Switching frequency derating in the
Hardware manual of the drive.
Example 1: If you need to fix the switching frequency to a certain value as with some
external filters, set both the reference and the minimum switching frequency to this
value and the drive will retain this switching frequency.