Delta VFD022B21A - Speed Search During Start-Up; Speed Search Frequency During Start-Up; Compensation Coefficient for Motor Instability

Chapter 5 Parameters_VFD-B Series
5-90
Revision 10/2005, BE13, SW V4.08
08 - 19
Speed Search during Start-up
Factory Setting: 00
Settings 00 Speed search disable
01 Speed search enable

This parameter is used for starting and stopping a motor with high inertia. A motor with high inertia will take
a long time to stop completely. By setting this parameter, the user does not need to wait for the motor to
come to a complete stop before restarting the AC motor drive. If a PG card and encoder is used on the
drive and motor, then the speed search will start from the speed that is detected by the encoder and
accelerate quickly to the commanded frequency. Pr.08-04 and Pr.08-06 will be disabled when using this
parameter with PG feedback control.
CAUTION!
Please make sure Pr.07-04, Pr.10-10, and Pr.10-11 are set correctly. An incorrect setting may cause the motor to
exceed its speed limit and permanent damage to the motor and machine can occur.
08 - 20
aSpeed Search Frequency during Start-up
Factory Setting: 00
Settings 00 Setting Frequency
01 Maximum Operation Frequency (01-00)

This parameter determines the start value of the speed search frequency.
08 - 22
aCompensation Coefficient for Motor Instability Unit: 1
Settings 00~1000 Factory Setting: 00

The drift current will occur in a specific zone of the motor and it will make motor instable. By using this
parameter, it will improve this situation greatly.

The drift current zone of the big horse power motor is usually in the low frequency area.

It is recommended to set to more than 500.