6-148
2) For installations into facilities which restart after instantaneous power failures, use the running restart
function which searches the direction and speed of free running rotation and picks up smoothly to
reengage drive or use [IL] of the X terminal.
3) For simple systems, hardware can be constructed as Figure 6.6.7. However, when a more complex
process sequence is desired, construction of a system structure which operates on communication with
PLC is recommended.
4) Configuring motor parameters
Direct parallel connection method is a control method where a single winding motor is operated in
parallel by plural inverters. Therefore, the motor constant required for inverter to control the motor is
"1/number of connected inverter units".
When an operation with reduced number of inverters, a characteristic of the direct parallel connection
system, is performed, the motor constants need to be changed. In this inverter, the motor constants can
be used by switching in the selection of motor constant switching function of X terminal by presetting
the constant codes of vector with speed sensor and sensorless vector for up to three motors.
At present, motor can be operated only by direct parallel connection with two or three inverters
or by the operation reduced to one inverter
Table 6.6.20 shows a setting method of motor parameters including the time of the operation with
reduced number of inverters.
When performing the operation with reduced number of inverters in the direct parallel connection system,
set the motor constants after determining the definitions of motor constant codes.
In the case of direct parallel connection of 2 units, use M2 codes as
reference motor constants.
In the case of direct parallel connection of 3 units, use M3 codes as
reference motor constants.
<Definitions>
• M1: Maximum number of
connected units
• M2: Maximum number of
connected units-1 unit
• M3: Maximum number of
connected units-2 units
The reference motor constants denote a state of connection in
which the ratio of motor (one-coil motor) to inverter becomes
1:1.
Table 6.6.20 Explanation of Change of Motor Constants in the Operation
with Reduced Number of Inverters
Parameter code
Parameter name
M1 code M2 code M3 code
Coefficient of setting value in operation
with reduced number of inverters
Drive control P01 A01 A101
Motor selection P02 A02 A102
Maximum speed F03 A06 A106
Rated speed F04 A03 A103
Rated voltage F05 A04 A104
Rated capacity P03 A05 A105
x (1/No. of units participating in direct
parallel connection)
Rated current P04 A06 A106
x (1/No. of units participating in direct
parallel connection)
Number of poles P05 A07 A107
%R1 P06 A08 A108
%X P07 A09 A109
Exciting current/
magnetic Flux weakening
current (-Id)
P08 A10 A110
x (1/No. of units participating in direct
parallel connection)
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