Automatic Restart After A Temporary Alarm: Retrying; Catch On The Fly Process; Gain Profiling Speed Feedback In A Sensorless Mode (Sls Spdfbk Gains) - GE AV-300i User Manual

1.4.3.3.1 Automatic Restart after a Temporary Alarm: Retrying

Before the autocapture process starts, it is necessary to wait for the motor to be demagnetized in order to avoid
high current transient due to the E.M.F. (electromotive force) which causes Overcurrent alarms.
The demagnetizing time can be set in ms via the Catch rety dly parameter.
In general: the bigger the motor, the longer the time.
Too low values of Catch rety dly cause high insertion currents.
After the demagnetizing time, the speed autocaputure phase starts. This function is influenced by the Spd
search time and Vlt search time parameters.
The process starts by supplying the motor with a frequency equal to the one supplied by the inverter before the
alarm intervention; the machine flux is afterwards increased thus making it equal to the corresponding output
frequency value (V/f feature).
If during this phase the output current is higher than the motor rated one, the output frequency is decreased and
the flux increasing speed is made slower.

1.4.3.3.2 Catch on the Fly Process

The procedure is similar to the above-mentioned one; the demagnetizing time is set via the Catch demag dly
parameter while the synchronism search starting speed via Catch init speed in rpm.
Example: switching of a mains (AC lines) connected motor (4 poles) (AC 50Hz) on the inverter.
- Set Catch init speed = 1500
- Inverter in a STOP condition
- Disconnect the motor from the mains and switch it on the inverter
W !
ARNING
No voltage can be applied on the inverter output (terminals U2, V2, W2). No direct connec-
tion between input and output is allowed (Bypass).
Pay particular attention to the sequences of the switching contacts between the network and the inverter.
- Give the START command to the inverter
Act on the Spd search time and Vlt search time parameters as stated before.
W !
ARNING
When this function is selected and if the power or the alarm have been reset, the drive
automatically starts its normal functioning procedure. This function must be used only with
applications which do not put in danger people or things during their automatic reset. Any-
way, the enforced safety rules have to be taken into consideration.

1.4.4 Gain Profiling Speed Feedback in a Sensorless Mode (Sls SpdFbk Gains)

The function is active only with a Sensorless mode.
With a Sensorless mode the motor speed is estimated. The gains of this observer depend on the speed, on
Motoring or Regen. It is possible to set a Profile for the gains. In both operating areas (quadrants).
Each Profile is defined by three segments:
H = High -
For each segment it is possible to state the % Proportional Integral gain of the speed.
Ch.1
50
M = MedPoint -
—————— Function Description ——————
GEH-6641E
L = Low