Protective Functions - Larsen & Toubro C*2000 Series User Manual

12. Troubleshoot and maintenance

12.1 Protective functions

When a fault occurs, the protective function will be activated, and the fault (shown as the
below table) displays on keypad. The cause must be corrected before the fault can be cle
ared. If the protective function keeps active, it could lead to the reduction of inverter
lifetime and damage to the equipment.
Protection on output current and input voltage of the inverter
Fault display Protective function
Over current
Short circuit
Ground fault
Inverter overload
Overload protection
Overheating
Output phase loss
Over voltage
Low voltage
Cx2000 AC Drive
Chapter 12 Troubleshoot and maintenance
Warning!
Description
The inverter turns off its output when the output current of the
inverter flows more than the inverter rated current.
When IGBT's Arm is short and output short occurs, the inverter
turns off its output
The inverter turns off its output when a ground fault occurs and the
ground fault current is more than the internal setting value of the
inverter.
The inverter turns off its output when the output current of the
inverter flows more than the rated level (150% for 1 minute).
The inverter turns off its output if the output current of the inverter
flows at 150% of the inverter rated current for more than the current
limit time (1 min).
The inverter turns off its output if the heat sink overheats due to a
damaged cooling fan or an alien substance in the cooling fan by
detecting the temperature of the heat sink.
The inverter turns off its output when the one or more of the output
(U, V, W) phase is open. The inverter detects the output current to
check the phase loss of the output.
The inverter turns off its output if the DC voltage of the main circuit
increases higher than 400 V when the motor decelerates. This fault
can also occur due to a surge voltage generated at the power
supply system.
The inverter turns off its output if the DC voltage is below 180V
because insufficient torque or overheating of the motor can occur
when the input voltage of the inverter drops.
12-1