Soft Starter For Three Phase Induction Motor

Fault

Cause of fault

Solutions

Overvoltage protection

Main circuit voltage is too high

1. Check whether the main circuit voltage is too high.

2. Check whether the parameter Q24 of the overvoltage protection value is set correctly.

Undervoltage protection

Main circuit voltage is too low

1. Check whether the main circuit voltage is too low.

2. Check whether the parameter Q26 of overvoltage protection value is set correctly

Phase voltage imbalance

Three-phase power supply voltage imbalance

1. Check whether the main circuit voltage is three-phase unbalanced.

2. Check whether the parameter Q23 of the voltage imbalance protection value is set correctly.

SCR abnormality

Check whether the thyristor is short-circuited.

Leakage blocking

Check the insulation of three-phase winding to ground.

Starting timeout

Starting time is too long

1. Check whether the current limiting signal is set too small.

2. Whether the starting time limit B12 parameter is set too small.

SCR overheat

Internal radiator overheated?

Poor ventilation of the machine

1. Check whether the fan works reliably.

2. Reduce the starting frequency. Check whether the control power supply voltage is too low.

Motor temperature

motor temperature detecys by PTC thermal resistor inside the motor is too high

1. Check whether the PTC circuit is closed and the input is connected.

2. Check and correct the cause of high temperature.

Restart the motor after it has cooled down enough.

Frequent starting

Starting too often

The start frequency exceeds the set minimum start interval parameter Q09..

Frequency fault

Frequency out of range

Check and change the power supply frequency.

Zero sequence protection

Check that the three-phase leakage exceeds the design value

Tap timeout

Tapping time is too long

The starting time exceeds the set starting time limit parameter B13.

3-phase high-voltage squirrel-cage asynchronous motor, 

synchronous motor