Mitsubishi Electric FR-A820-00046 Instruction Manual page 676

(A) Application parameters
Operation of load torque high-speed frequency control
● When the average current of the current averaging range (chart A below) during operation with
the X19 signal ON is the "rated inverter current × Pr. 271 setting (%)" or less, the maximum
frequency automatically becomes the Pr. 4 "Multi-speed setting (high speed)" setting value.
● When the average current of the current averaging range (chart B below) during operation with
the X19 signal ON is greater than the "rated inverter current × Pr. 272 setting (%)", the maximum
frequency automatically becomes the Pr. 5 "Multi-speed setting (middle speed)" setting value.
● During regeneration load operation, the Pr. 5 setting is the maximum frequency regardless of the
average current.
● When Pr. 273 is used, the current averaging range can be set between one half of the frequency
of the Pr. 273 setting value and the Pr. 273 set frequency. (However, the setting value must be
smaller than Pr. 5 setting.)
Pr. 4
Pr. 5
1
Pr. 5
2
STF
(STR)
X19
Fig. 5-237:
● When the average current is larger than "rated inverter current × Pr. 271 setting (%)" and smaller
than "rated inverter current × Pr. 272 setting (%)", linear compensation is performed as shown
below.
Fig. 5-238:
5 - 496
Power running
A
Current averaging range
Less than
Pr. 271 setting x rated current
ON OFF
ON
Operation of load torque high-speed frequency control
Frequency
Pr. 4
(60 Hz/50 Hz)
Pr. 5
(30 Hz)
Value in parentheses is initial value.
Current averaging range
B
Current averaging range
Pr. 272 setting x rated current
or more
ON
ON
Pr. 271 Pr. 272
(50 %) (100 %)
Parameters
Regenerating
OFF
ON
ON
Average current
Time
OFF
OFF
I002680E
I001626E