Operating Instructions ACU
The time required until the motor has come to a standstill results from the regenerative energy of
the system which results in an increase in the DC link voltage. The DC link voltage set with the
parameter Reference Shutdown Value 676 is used by the voltage controller as a control figure and
kept constant. The voltage rise enables optimization of the braking behavior and the time until the
drive has come to a standstill. The behavior of the controller can be compared to stopping behavior
2 (Shutdown and Stop), as the voltage controller brings the drive to a standstill at the maximum
deceleration ramp and supplies it with the remaining DC link voltage.
If the DC-Link Voltage is restored before the drive has stopped, but after dropping below the
Shutdown Threshold 675, the drive will be decelerated until it stops.
If the mains voltage is restored after the shutdown of the drive but before the undervoltage switch-
off has been reached, the frequency inverter signals a fault. The control unit displays the error signal
"F0702".
If the mains failure without shutdown (Shutdown Threshold 675 = 0 Hz) takes so long that the
frequency has been reduced to 0 Hz, the drive is accelerated to the reference frequency when the
mains supply is restored.
If the mains failure with or without shutdown takes so long that the frequency inverter shuts off
completely (LED's = OFF), the frequency inverter will be in the "Standby" state when the mains
supply is restored. If the inverter is released again, the drive will start. If the drive is to start
automatically after restoration of the mains supply if the inverter is released permanently, Operation
Mode 651 of Auto Start must be switched on.
The Shutdown Threshold 676 becomes effective below the frequency value Shutdown
Threshold 675.
To Next Page
Need help?
General
