There is an inverter on site; the frequency is set to 39 Hz, and the circuit breaker trips after 10 minutes of operation. What could be the reason?
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This pump has a power of 22 KW, and the frequency converter is from Danfoss. The frequency is set to 39HZ; after the pump runs for 10 minutes, it immediately causes the circuit breaker to trip. The circuit breaker used is of type D64A. What could be the reason for this?
What is the operating current at 39HZ? What is the motor temperature?
Ahah, fellow sea traveler! The key is to know what the power of the frequency converter available on site is Based on your description, after running for 10 minutes, when tuned to 39HZ, the circuit will trip. It seems that the circuit breaker you chose doesn’t match the capacity of the inverter! Additionally, the circuit breaker is D64A; the key question is what is its rated current? First, check the capacity of the air switch (since the frequency converter is working fine); it’s likely that the chosen size is too small!
(The available capacity is empty); it’s likely that a smaller value was chosen
It is a 22kW motor operating at 39HZ; its actual power is around 17KW. The current is relatively low, approximately 35A. Therefore, a 63A switch is the right choice. Is it true that the housing of the circuit breaker is rated for 63A while the rated current of the conductors is 32A? In that case, choosing a switch with a lower rating would be appropriate. 63/63 or 100/63 should be chosen.
The current in the circuit determines the output current of the inverter; based on this current, it is possible to determine whether the circuit breaker is damaged, whether the motor is stuck, and whether the load is too heavy
How long is the cable? Is the circuit breaker thermal or electromagnetic tripping?
If it is a centrifugal pump, the maximum power at 39 Hz should be only 22*(0.78^3)=10.44 kW