Inverter trips due to excessive current
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Our unit has a Siemens MDV frequency converter, presumably 75KW in capacity, equipped with a 55KW screw fan. It starts up normally, but shuts down once a load is applied. The error code indicated is over-current, yet the actual current drawn by the frequency converter is not above the limit； Just replace the inverter; what causes this issue? What’s wrong with the inverter? I hope all fellow sailors can give me some guidance...
1. There are issues with the parameter settings of the inverter. 2. There are problems with the inverter’s current detection and protection circuitry
The electronic components inside the circuit board age
Reply to 3# 419677327: If this frequency converter is new, it’s a good idea to check its parameter settings.
I’ve never used MDV; it can’t be MASTERDRIVES. SIEMENS’ frequency converters can perform both static and dynamic identification, automatically detecting parameters such as motor resistance, cable resistance, stator and rotor windings, and magnetic leakage. If these parameters differ too much, many inexplicable problems will arise.
One of the rectifier modules in the inverter is not functioning; as the output current from the inverter module itself does not exceed the limit, overcurrent in the other two input rectifier modules on the input side causes the inverter to shut down.
Check the actual current; if the current value is normal, the problem lies in the inverter’s detection circuit.