Mitsubishi Electric FR-A700 Technical Manual page 216

2.6.4 Energy saving control and optimum excitation control [Pr. 60]
Without a fine parameter setting, the inverter automatically performs energy saving operation.
This inverter is optimum for fan and pump applications
[Pr. ] Name
Energy saving control
60
selection
(1) Energy saving operation mode [Pr. 60 = 4]
A700 F700
Set [Pr. 60 = 4] to perform operation with the minimum
output power.
1) Control method
After the output frequency has become constant
(acceleration or deceleration is complete), the
output voltage is reduced gradually and operation
is performed with the output power (product of
current and voltage) being minimum.
When the output current begins to increase due to
the increase in load torque, the output voltage is
increased up to the normal V/F pattern to
generate the torque required to maintain the
speed.
The output voltage is controlled within the range
of +0% to -50% in relation to the normal V/F
pattern, and the settings of [Pr. 0 Torque boost] and
[Pr. 14 Load pattern selection] are ignored. By
setting [Pr. 60 = 0] (Normal mode), the settings of
[Pr. 0, Pr. 14] are valid.
2) Restriction conditions
• When Advanced magnetic flux vector control,
Simple magnetic flux vector control, Real
sensorless vector control, or vector control is
selected, the selection of the energy-saving
mode is invalid.
• When the encoder feedback function has been
selected with the plug-in option (FR-A7AP) fitted
to the inverter, the selection of the energy-saving
mode is invalid.
3) Applications
Appropriate application
• Machine which is operated for a long time at
constant speed, e.g. fan, air conditioner.
Inappropriate application
• Application in which large load torque is
applied
Since there
consumption loss, no energy-saving effect is
expected.
• Machine which makes frequent acceleration/
deceleration
Since torque is necessary for acceleration/
deceleration, no energy-saving effect is
expected.
Setting
Initial Value
Range
0
is naturally little power
Description
0
Normal operation mode
4 Energy saving operation mode
9 Optimum excitation control mode
4) Dedicated parameters
When constant speed is achieved in the energy-
saving mode, the output voltage is automatically
tuned and there are no dedicated parameters to
be set.
5) Energy-saving effect
The energy-saving effect depends greatly on the
load magnitude.
Power consumption (%)
100
50
0
Guideline of energy-saving mode
In applications
equipment, inverter operation produces a larger
energy-saving effect on the running cost than
damper control by commercial power supply
operation. The energy-saving effect depends
greatly on the speed (load).
Power consumption (%)
100
Damper control
50
Constant-torque
pattern
Inverter
control
0
Energy-saving effect by air-conditioning equipment
250
PARAMETER
common
(common)
Available Inverters
A700 F700
—
Normal mode
Energy-saving mode
50 100 Load (%)
such as air conditioning
Variable-torque pattern
Energy-saving mode
Optimum excitation
control
50 100
Speed (= air volume) (%)
E700
D700
—