Energy-Saving - Omron VARISPEED F7 User Manual

Energy-saving

To use the energy saving function, set b8-01 (Energy Saving Mode Selection) to 1. Energy-saving control can
be performed in all control methods. The parameters to be adjusted are different for each. In the V/f control
modes adjust b8-04 to b8-05. In Open Loop and Closed Loop Vector control adjust b8-02 and b8-03.
Related Parameters
Parameter
No.
b8-01 Energy-saving mode selection
b8-02 Energy-saving gain
b8-03 Energy-saving filter time constant
b8-04 Energy-saving coefficient
b8-05 Power detection filter time constant
b8-06 Search operation voltage limiter
E2-02 Motor rated slip
E2-11 Motor rated output power
* 1. The value for Open Loop Vector Control is given. The factory setting is 1.0 in Closed Loop Vector Control.
* 2. The factory setting is 2.00 s for Inverters with a capacity of 75 kW and more.
* 3. The factory setting depends on the Inverter capacity (the value for a 200 V Class Inverter of 0.4 kW is given).
Adjusting Energy-saving Control
The method of adjusting the energy-saving control function depends on the control method. Refer to the fol-
lowing when making adjustments.
V/f Control Modes
In the V/f control modes the voltage for optimum motor efficiency is calculated and becomes the output volt-
age reference.
b8-04 (Energy-saving Coefficient) is preset assuming that motor and inverter capacity are the same. If the
•
inverter capacity differs from the motor capacity, set the motor capacity in E2-11 (Motor Rated Output
Power). Also, adjust b8-04 in steps of 5 % until the output power reaches its minimum. The higher the
energy-saving coefficient, the higher is the output voltage.
To improve the responsiveness when the load fluctuates, reduce the power detection filter time parameter
•
b8-05. If b8-05 is set too small, however, the motor rotations may become unstable under light load condi-
tions.
Motor efficiency varies due to temperature fluctuations and differences in motor characteristics. Conse-
•
quently the motor efficiency has to be controlled. To have optimized efficiency, the search operation varies
the output voltage. Parameter b8-06 (Search Operation Voltage Limiter) limits the range for the voltage
search operation. For 200 V Class Inverters, a range of 100% is equal to 200 V and for 400 V Class Invert-
ers a range of 100% is equal to 400 V. Set b8-06 to 0 to disable the search operation voltage limiter.
Name
288.20
2.90 Hz
Control Methods
Change
Factory during
V/f with
Setting Opera-
V/f
PG
tion
0 No A A
* 1
Yes No No
0.7
* 2
Yes No No
0.50 s
* 3
No A A
20 ms No A A
0% No A A
*3
No A A
*3
No Q Q
0.40
Open Closed
Loop Loop
Vector Vector
A A
A A
A A
No No
No No
No No
A A
Q Q
6
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