Megmeet Inverter - Summary of Common Faults of High Voltage Inverter (21-32)

21。 The unit is overheating

The radiator in the unit is equipped with a temperature switch (normally closed point), and when the temperature exceeds 85°C, the normally closed point of the temperature relay is disconnected, and the unit is overheated and faulty.

Check whether the fan on the top of the cabinet is working normally, whether the fan switch of the unit cabinet is tripped, and whether the filter screen is blocked (take a piece of A4 paper and put it on the filter screen to see if it can be adsorbed, otherwise the filter screen needs to be cleaned); Whether it works in an overload state for a long time, whether the ambient temperature is too high (the ambient temperature should be lower than 45 °C, otherwise it is necessary to strengthen ventilation), install a ventilator on the wall or install an air duct or refrigeration equipment on the top of the cabinet;

The unit control board is broken, and finally check whether the power unit temperature relay is normal.

22。 The unit is overpressurized

The DC bus voltage exceeds the protection value, and the inverter reports that the unit is overvoltage.

When the inverter is running, if the output voltage of a unit is low, it will cause the three-phase output to be unbalanced, and the unit will be overvoltaged; During the commissioning of the no-load motor, it is easy to overvoltage the DC bus and the overvoltage of the A1/B1/C1 unit, at this time, the reference voltage can be appropriately lowered.

Check whether the input high-voltage power supply exceeds the allowable maximum value (when the supply voltage is too high, the transformer tap can be adjusted to 105%);

If there is an overvoltage during the deceleration process, please increase the deceleration time setting value of the inverter appropriately.

23。 Fiber failure

When the system fails to detect unit communication in the power-on state, the optical fiber fault is reported. The power unit controls whether the power supply is normal (when normal, the green indicator light is on), otherwise replace the power unit; Whether the fiber optic connector of the power unit and controller has fallen off and whether the optical fiber has been broken.

24。 Unit bypass

When the hardware of the unit is configured with a bypass, and the number of bypass stages in the parameter setting is non-zero, if the unit has three faults: drive failure, fuse failure, and unit overheating, the unit bypass will occur.

If a unit fails and is bypassed, the other two units in the same position will also be bypassed, at this time, the inverter can still start and run, but due to the reduction of the number of series units per phase, the rated output voltage and rated capacity will be reduced. When the unit bypass occurs, the cause must be identified, and the faulty unit must be shut down as soon as possible to replace (the remaining two-phase bypassed unit does not need to be replaced); Clean up the unit driver board and unit control board, if the dust collection of these two circuit boards is too thick, it may cause false alarms.

25。 The operating frequency is not consistent with the given frequency

There are several reasons for this situation: In the process of acceleration and deceleration, limited by the acceleration and deceleration time, there is a process for the output frequency to reach a given frequency;

When the system voltage is too high, the frequency converter cannot stay at a numerical point to avoid DC bus overvoltage protection due to the requirements of its own protection. At this time, it is recommended to connect the transformer tap to 105%; If the output current of the inverter exceeds the set current limiting current value, the inverter will automatically reduce the frequency to reduce the output current and avoid overcurrent protection tripping. This usually occurs when the input voltage is too low or the load bursts;

In the event of an instantaneous power failure, in order to maintain the motor in a controllable state, the inverter will automatically decelerate and obtain energy from the motor; A Hall element, cell detection board, or signal board is faulty.

26。 The monitor has a black screen

Press the system reset button on the cabinet door (the system reset will not affect the normal operation of the inverter); If it still cannot be recovered, check whether the power terminal of the monitor is off, whether the connection wire is loose, whether the 5V and 15V power supply are normal, and whether the monitor line is obviously damaged;

If there is interference, otherwise replace the monitor.

27。 Parameters cannot be modified

If the parameter modification option is set to Forbidden in a function parameter, all parameters except for the parameter and the given frequency or given parameter cannot be modified.

Most of the parameters cannot be modified during operation.

28。 The inverter automatically restarts after a shutdown

In remote control mode, the start and stop can only be done through the remote terminal.

If the starting mode in the parameter setting is level start (closed start, disconnected stop), the inverter will be automatically started and run when the emergency stop signal is disconnected or the inverter is stopped by other means during operation, but when the emergency stop signal is re-closed, because the remote start level signal is still there, the inverter will automatically start running.

29。 When the inverter is powered on, due to the excitation inrush current of the transformer and the charging of the unit capacitance, the instantaneous current effective value can reach up to 6-7 times of the rated current of the inverter, and the duration is tens of milliseconds; If the setting value of the upper current protection of the inverter is too small, it will cause the upper level switch quick break protection to trip.

Adjust the setting value of quick-break protection of the upper switch cabinet.

30。 The output frequency oscillates at low speed during start-up

At low speed, some motors fluctuate very much because of the influence of cogging effect, etc., and the inverter may have current limiting at this time, so that the inverter can accelerate, limit the current and decelerate, etc., and cannot accelerate normally. Increase the current limit current setting; Reduced start-up time; If the output voltage of a unit is low, replace this unit;

31。 When the automatic bypass cabinet is automatically bypassed, the upper switch cabinet trips

Check whether the time of the delay pick-up time relay in the bypass cabinet is between 1.5S and 3S; Whether the setting value of the switch cabinet is too small (it should be more than 5 times the rated current of the motor); The quick-break protection time of the switch cabinet is set to be greater than 0.1S.

32。 The external terminal has an induced AC voltage

It may be remote start/stop, high-voltage breaking, system reset signal line induced voltage, it is recommended that the passive signal and the 220V AC power supply be wired separately, in this case, it is best to use the shielded wire to ground at both ends;

It may be that the signal line on the remote control box is tied together with the power line to cause the induced voltage, it is recommended to re-wire in the remote control box, and it is best to use the shielded wire for the signal without reason, and the shielded wire stripping wire should not be too long; The 4-20mA current signal has an AC induced voltage (below 10V), and can be connected between the current signal and ground with a 275V/0.33uf.

Megmeet Inverter - Summary of Common Faults of High Voltage Inverter (21-32)

Megmeet Inverter - Summary of Common Faults of High Voltage Inverter (21-32)

Sections viewed

Contact

working hours