Lust CDA3000 - Page 181

Application Manual CDA3000
5-67
5 Software functions
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EN
FR
(1) Longest possible DC-link buffering by DC-link controlled
speed reduction
(regenerative braking)
After a detected power failure, the DC-link voltage is regulated to the
parameter value 341-PFVON. The motor is automatically run in regenera-
tive mode and braked as required by DC-link buffering. If the rotational
energy of the motor is no longer adequate for DC-link buffering, when the
fixed undervoltage shutdown threshold U
Zkoff
is reached the power stage
is disabled and the motor coasts uncontrolled.
(1.1) Setting with restart (PFSEL = RETRN)
If the mains power is restored before the undervoltage shutdown thresh-
old U
Zkoff
is reached, the inverter automatically returns to speed-control-
led operation. Regardless of the current speed of the motor, the motor is
accelerated back up via the preset ramps ACCRx and governed to the
frequency reference active prior to the power failure.
(1.2) Setting without restart (PFSEL = NORET)
When the mains power is restored the inverter remains in power failure
bridging mode. The motor coasts uncontrolled, if it has not already come
to a standstill. The motor can be accelerated again with a new controller
enable and start signal.