Hitachi J300U Series Energy conservation running Outline of the function, Large load

2.Energy conservation running

[Outline of the function]

This is a function for automatically setting the output voltage corresponding to the load during the V/F control running and suppressing useless power.

The function is effective for a load of reduced torque characteristics such as a fan and pump.

I

When the load of an induction motor is constant as shown in the drawing on the right, there is a voltage at which the current is minimized. When the current is minimized, the power is also minimized. The function auto- matically searches this voltage.

Large load

O	V1	V2	V
[Precautions]

1.The output voltage is decreased so as to minimize the current. The search limits are the voltage of torque constant characteristic ±50%.

2. The function is performed	V
under comparatively slow	100%

control. Therefore, when a sudden load change (such as an impact load) occurs, the motor may stall.

50%

O

f

➤

Range where the energy conservation is effective

A-8