1.3 Wiring (for looms other than towel weaving machine)
37
1.3.3
Cable Capacity
The cable capacity shall be determined according to the motor rated current with the supply voltage
fluctuation and voltage drop. Please consult with the person in charge of electricity or electric spe-
cialists.
[ 1 ] Supply voltage fluctuation and line voltage drop
(1) The voltage received by the loom drops due to supply voltage fluctuation and the voltage drop at delta-
starting by the cable resistance. Keep the total voltage drop within10% of the contract voltage.
(2) The voltage drop by supply voltage fluctuation and the voltage drop by cables
①
and
②
can be corrected
by torque boost effect by the inverter. The maximum inverter voltage up ratio by torque boosting is 15 to
20% of the standard inverter output (output voltage of the inverter in loaded state). Therefore, the total
voltage drop by supply voltage fluctuation and cables can be allowed up to this correction limit.
Contracted
voltage
(supply voltage)
Voltage drop by fluctuation
Voltage drop by cable
③
Voltage received
by loom
Cable
③
(between circuit breaker on switchboard and loom)
Circuit
breaker
Circuit
breaker
Cable
①
(between circuit
breaker on switchboard
and inverter)
Inverter
Cable
②
(between inverter
and loom)
JA loom
Voltage drop
by fluctuation
Contracted
voltage (supply
voltage)
Voltage drop by cable
①
Inverter input voltage
Inverter output
voltage (with
voltage correction)
Inverter output voltage
adjustment by torque
boost (15 - 20% up)
Inverter output
voltage (without
voltage correction)
Voltage received
by loom
Voltage drop on inverter input side
(Total of voltage drops
and )
Voltage drop
by cable
②
Plant
switchboard
a
b
a
b
c
c
※
