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Chapter 4 Explanation of Functions
4 - 88
4.2.95 Motor constants selection
Adjust the motor constant settings to the motor to be driven by the inverter.
When using a single inverter to drive multiple motors in the control mode based on VC, VP, or free V/f
characteristic, calculate the total capacity of the motors, and specify a value close to the total capacity for
the motor capacity selection (H003/H203).
When the automatic torque boost function is used, the motor constant settings that do not match the
motor may result in a reduced motor or unstable motor operation.
You can select the motor constants that are used when the control mode is the sensorless vector control,
0Hz-range sensorless vector control, or vector control with sensor from the following three types:
(1) Motor constants of Hitachi general-purpose motor
(2) Motor constants tuned by offline auto-tuning
(3) Arbitrarily set motor constants
The motor constants set for the 1st motor control apply to the 3rd motor control.
Item Function code Data or range of data Description
00 Constant torque characteristic (VC)
01
Reduced-torque characteristic (1.7th power
of VP)
02 (*1) Free V/f characteristic
03 (*1) Sensorless vector control (SLV)
04 (*1) 0 Hz-range sensorless vector control
V/F characteristic
curve selection
A044/A244/
A344
05 (*1) Vector control with sensor (V2)
00 Hitachi general-purpose motor constants
01 Motor constants tuned by auto-tuning
Motor data
selection
H002/H202
02
Motor constants tuned by online auto-
tuning
Motor capacity H003/H203 0.2 to 75.0 (kW)
Motor poles setting H004/H204 2, 4, 6, 8, or 10 (poles)
Motor constant R1 H020/H220 0.000 to 65.53 (Ω) (*2)
Motor constant R2 H021/H221
0.000 to 65.53 (kgm
2
)
(*2)
Motor constant L H022/H222 0.00 to 655.3 (mH)
Motor constant Io H023/H223 0.00 to 655.3 (A) (*2)
Motor constant J H024/H224
0.001 to 9999. (kgm
2
)
(*3)
Auto constant R1 H030/H230 0.000 to 65.53 (Ω)
Auto constant R2 H031/H231 0.000 to 65.53 (Ω)
Auto constant L H032/H232 0.00 to 655.3 (mH)
Auto constant Io H033/H233 0.00 to 655.3 (A)
Auto constant J H034/H234
0.001 to 9999. (kgm
2
)
*1 Any of "00" to "05" can be selected for the 1st motor (A044). Only "00" to "04" can be selected for the
2nd motor (A244). Only "00" or "01" can be selected for the 3rd motor (A344).
*2 If you copy the data from a J300 series inverter to your SJ700 series inverter, set constants R1, R2,
and Io as follows:
R1
SJ700
= R1
J300
/1.125 R2
SJ700
= R2
J300
/1.2 Io = V/{272 x (2 x M
J300
+ L
J300
) x 10
-3
}
V: Voltage class (200 or 400 V)
*3 Convert the moment of inertia (J) into the motor shaft data. When the value of J is large, the motor
response is fast, and the motor torque increases quickly. When the value of J is small, the motor
response is slow, and the motor torque increases slowly. To control the response, set the value of J,
and then adjust the speed response (H005/H205).
*4 In the modes of sensorless vector control, 0Hz-range sensorless vector control and vector control with
sensor, inverter may output reverse to given operation command in the low speed range as a nature
of those control. In case there is a specific inconvenience for example reverse rotation damage the
machine, enable the reverse run protection (b046). (see 4.2.101: Reverse run protection function)
Arbitrary setting of motor constants
For the arbitrary setting of the motor constants, the function codes requiring settings vary depending on
the settings of the 1st/2nd control function and the motor constant selection.
- When the 1st/2nd control function is enabled and "00" is specified for the motor constant selection →
Directly input the desired values for "H020" to "H024".
- When the 1st/2nd control function is enabled and "01" or "02" is specified for the motor constant
selection → Directly input the desired values for "H030" to "H034".
When the offline auto-tuning has not been performed, the constants (Hitachi general-purpose motor
constants) of the motors in the same capacity class as the inverter have been set for "H030/H230" to