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2) Decreasing output voltage

Setting of V/f control mode selection ￿￿=￿ (Voltage decrease curve)

This is appropriate for load characteristics of such things as fans, pumps and blowers in which the torque in relation

to load rotation speed is proportional to its square.

Base frequency voltage 1

 

￿￿￿

 

 

Output

 

 

voltage

￿￿

 

[V]/[%]

0

Output frequency [Hz]

 

 

Base frequency

￿￿

3) Increasing starting torque

Setting of V/f control mode selection ￿￿=￿ (Automatic torque boost)

Detects load current in all speed ranges and automatically adjusts voltage output (torque boost) from inverter. This gives steady torque for stable runs.

5

Base frequency voltage 1

￿￿￿

Output voltage

[V]/[%]

0

:The torque boost rate is adjusted automatically.

Output frequency [Hz] Base frequency ￿￿

Note:This control system can oscillate and destabilize runs depending on the load. If that should happen, set V/f control mode selection ￿￿ to ￿ (Constant torque characteristics) and increase torque manually.

"Motor constant must be set.

The motor constant can be set in any of the following two ways:

1)Automatic setting

Enter the following information that is indicated on the motor nameplate, and then execute the auto-tuning 1 command (Set ￿￿￿￿ to ￿, and then reset ￿￿￿￿ to ￿.).

<Information indicated on motor nameplate>

￿￿(Base frequency), ￿￿￿ (Base frequency voltage), ￿￿￿￿ (Motor rated capacity), ￿￿￿￿ (Motor rated current), ￿￿￿￿(Motor rated rotational speed)

￿Refer to 6.22 selection 2.

2)Manual setting

Set each motor constant manually.

￿Refer to 6.22 selection 3.

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Toshiba VF-AS1 Decreasing output voltage, Motor constant must be set, Torque boost rate is adjusted automatically