Energy Conservation Running - Hitachi J300 Series Instruction Manual

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.
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.
[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
under comparatively slow
control. Therefore, when a
sudden load change (such as
an impact load) occurs, the
motor may stall.
CTi Automation - Phone: 800.894.0412 - Fax: 208.368.0415 - Web: www.ctiautomation.net - Email: info@ctiautomation.net
I
O
V
O
Range where the energy
conservation is effective
A-8
V
V
2
1
100%
50%
f
Large load
V