88
SANTERNO
USER MANUAL
● High power loss:
High-voltage power loss is usually caused by normal switch operation. If the unusual high-pressure breaking
(without trouble record, no break operation) occurs, check the switchgear breaker circuit.
● VFD over current:
When VFD output current is 1.5 times larger than rated current, then over current will protect.
1. Whether output voltage detection board is normal without short circuit or discharge;
2. Check fiber to plug fasten, main circuit connection screws are fasten; Check Hall power and Hall output current
signal;
3. Whether acceleration time is too short, torque lift is too large, start-up frequency is too high;
4. Whether motor or load is rotor locked, whether destroys the motor winding and output cable isolation;
5. Check all the cells work normally (dispatch cell connection copper bars, using multi-meter or oscilloscope to
measure the waveform;
6. Whether the input voltage is too low;
7. There is power factor correction capacitor or surge absorption device at output side, it may cause resonance
together with inductance. Cancel the related devices.
8. Check the cell detection board to see if short circuit or destroyed.
If the above troubleshoots can not solve the problem, please replace signal board or main control board. On some
sites, the current fluctuates at low speed since cogging effect. At this time, there maybe current limit causing
repeat VFD acceleration and deceleration, in this case, it needs to decrease the acceleration time, enlarge the
current limit ratio to make the motor quickly runs through the fluctuation range to avoid over current protection. (In
this condition, if the cell output voltage is low, replace the cell).
● Motor over-current:
VFD output current at more than 1.1 times of the motor rated current, start calculate the motor over current,
I^2t
accumulatively reaches over the permit value, it will report motor over current fault
1.Check whether the setting value for motor rated current are correct;
2.Whether the electrical or mechanical load is blocked;
3.Whether power supply is too low.
● The motor is not running after VFD runs:
1. Check VFD output to see whether there is contactor or switch cabinet;
2. Check VFD output primary cables connect to the motor;
3. Observe if there are output current and output voltage in the HMI, if voltage displayed, but no current, it means
the main circuit from VFD to motor is open circuit, if both voltage and current displayed, check if there is single
phase grounding, if motor rotor winding is at open status.
● Cell heavy fault:
There are totally five kinds of heavy fault, including the fuse failure, IGBT failure, overheating, DC bus over-
voltage, fiber fault, of which the former three kinds of fault can be bypassed (valid with bypass cell equipped and
the bypass level set to non-zero)
