Chapter 8 Troubleshooting & Maintenances
8-7
The displayed value is speed command. Set the desired value (ex: 0.0%) and press [ENTER] key.
(2)
Follow the same steps to check Ai2 ~ Ai3.
9) Motor detects speed reference but motor rpm is showing decreasing while motor is
overheated or hunting
.
(1)
Check the motor wiring.
☞
There is a possibility of incorrect motor wiring when motor is 220V / 380V dual rating. Motor does
not normally rotate when pole number setting is incorrect. However, motor may get damaged in
case of miswiring. If this problem occurs, contact motor sales office. Refer to Power terminal
description in this manual.
(2)
Is motor capacity set correctly?
☞
Check PAR_07 motor rating selection is set the same as motor in use. See the nameplate for
motor rating.
(3)
Is motor parameter set correctly?
☞
Motor parameters vary by manufacturer.
10)
Nothing displayed on the LCD?
(1)
Is the connection of inverter and keypad tight?
☞
Check the inverter and Keypad connection.
(2)
Is input power turned on ?
☞
Check inverter power is applied. If nothing is displayed on the LCD in this condition, contact LS
representatives.
11) Motor speed oscillates and speed is not constant during constant Run.
(1)
Is encoder wired using twisted shield cable?
☞
encoder signal wiring should be conducted with Twisted Shield Cable. Otherwise, speed may
oscillate at low speed (or high speed) due to encoder input noise, leading to motor vibration or
abnormal motor sound at stop.
(2)
Is the connection of inverter and motor and encoder grounding proper?
☞
Check the grounding of inverter and encoder is connected. This could occur when not connected.
Fixed screw for the connection of encoder grounding and the inverter is located on the right bottom
side of the control PCB. Loosen the fixed screw and insert the ground wire of the encoder and
tighten the screw. (Refer to encoder wiring diagram). For grounding the motor, use G of the inverter