Chapter 8 Troubleshooting & Maintenances
8-8
Main terminal.
(3)
Connect inverter panel grounding connected with motor grounding to the building grounding.
☞
If not, incorrect motor speed may be input due to encoder input noise.
(4)
Is too large speed gain assigned to the inverter while motor load is light?
☞
Motor oscillates at stop when PI gain is set much larger than the actual load in CON_03 and
CON_04. Therefore, gain should be set accordingly. Responsiveness increases when P gain is set
higher and I lower but system may become unstable. Gain value varies system but generally set
30
~ 100%
for
P gain
and set
100 ~ 500ms for I gain.
(5)
Increase PAR_13 Enc LPF setting value.
(6)
Is there slip present at the connection of encoder and motor shaft?
☞
Poor encoder and motor connection may generate slip. Check the connection is tight.
12) Parameter change is not saved.
☞
Turn the power off and turn it on. If problem persists, contact LS representatives.
13) Motor input current is too large.
(1)
Check the motor wiring.
☞
Check the motor wiring for the use of 220V / 380V transition type motor. (Refer to Main circuit
terminal)
(2)
Are motor and inverter capacity set correctly?
(3)
Is the setting of motor constants appropriate?
☞
Refer to 2) and 9) and check the motor and inverter setting.
14) OC-U (V,W) trip occurs frequently during operation. (Motor input current is oscillating.)
(1)
check the encoder installation.
☞
If encoder connection is poor, motor vibration affects encoder and incorrect encoder signal is input
to the inverter. Vector inverter controls the speed from Encoder F/B value so it follows the input signal
whether correct or not, increasing inverter current. If so, contact motor maker or encoder
commission company.
(2)
Is there no inverter output phase loss?
(3)
Is the motor insulation not damaged?
☞
Refer to 13) and check the inverter and motor.