45kVA Three Phase Frequency Converter Trips during Emergency Stop

We have a 45kVA, three phase frequency converter (Model #: HZ-50-3345) with the 480V input voltage, Wye wiring type, & 50/60Hz output frequency options.
The HZ-50-3345 frequency converter output is set at 380V Line-Line @ 50Hz.
Our current electrical connections are as follows:
We are feeding the frequency converter with 480V from a 70A, 3 Pole, Breaker.
We ran (4) #4awg cables from this panel to the frequency converter unit
We are then feeding out of the frequency converter (load side) to a 100A Rated, 3Pole, 600V, 3W, disconnect that has 80A trip, 600V rated, Type RK5 fuses (FRS-R-80).
We ran (4) #2awg cables from the frequency converter to the disconnect.
The load side of the disconnect feeds process equipment that needs 380V @ 50Hz to run.

The issue we are currently experiencing is:
During the startup/testing of the process equipment fed by this converter, it will intermittently cause the frequency converter to trip and go into alarm mode. This does not occur every time, however, it has occurred multiple times and keeps occurring.
The sequence of events that we have found to most likely cause the trip has been:
The process equipment has a safety function that, when a sensor is set off, it will put the process equipment itself into an ‘Emergency Stop’ mode, shutting down all the motors, pumps, etc. for safety. Upon this “Emergency Stop” function, the frequency converter goes into alarm and shuts down all output power. Once we reset the converter and turn the output back on, things work as normal; Until the next time the safety sensor goes into ‘emergency stop’ mode and it repeats the above issue with the converter going into alarm and killing output power.
We do not see a spike in current on the converter’s LCD output readings, at any time, during the testing of the process equipment.
The highest amperage level we have read at any time was less than 5A.
This includes readings on all output current Phase Switch Positions. (U-V, V-W, W-U)
Is there a setting in the frequency converter that will cause an alarmed trip during a rapid shutdown of a load draw on the Unit? Do you have any suggestions on tests we can perform to ensure the HZ-50-3345 is operating properly?

Zak wrote:
Hi Zak,
There is no problem with the wiring of the converter, and the load device entering the emergency stop mode will not affect the output of the power supply. Now please follow the steps below to test and feedback:
1. First confirm that the machine is set to high voltage mode, setting the voltage to phase voltage mode, and adjust the voltage to 220V. When the phase voltage is 220V, the corresponding line voltage is 380V.
2. The converter needs to remain in phase voltage mode and continue to test and run your load device. When the converter trips, immediately turn the phase voltage switch on the operation panel to U（as shown in the attached picture) to check whether the U-phase voltage display is normal.
3. Repeat step 2 and run the machine again, when the converter trips, switch the switch to V and W, and check whether the V phase voltage and W phase voltage are displayed normally.
In this way, we would like to confirm whether the three-phase output of the converter is consistent, or whether one of the output voltages is abnormal.

ATO wrote:
Thank you for the guidance.
I have confirmed the output voltage was set as you have described below. (220V phase, 380V line)
Upon further investigation, it was noted that when the converter trips, it is losing voltage output on the U-phase.
This was confirmed with a meter reading Phase-Voltage directly between the U-phase and Ground at the equipment disconnect being fed from the converter.
Our reading was only 0.98 VAC.

Zak wrote:
The abnormal U-phase output voltage is usually caused by the failure of the U-phase driver board. To solve the problem as soon as possible, we will send you a new driver board to replace it for free. Notes on replacing the circuit board:
1. Before replacing the circuit board, disconnect the input power and discharge the 6800UF electrolytic capacitor. The capacitor can be quickly discharged by ordinary incandescent bulbs or (≥20W 500 ohms) resistors. If you have no such thing, please stop the converter for 20 -30 minutes, and then use the DC voltage range of the multi-meter to measure and confirm the capacitive voltage is ≤ 5V, and then you can start the following inspection for security.
2. After the new driver board is installed, please double-check that each connection plug is firmly connected, and then start it with no load and test it.

We just had the even happen again. On the board behind the display, I could see an LED lit up. The board has LED07 printed for that light. What does that mean? We lost a phase and the unit was in alarm. This is in the same phase we changed the device you sent to us.  

Zak wrote:
The circuit board shows that LED07 is flashing, which means that the driver board is protected.
Is the load driving when the fault LED07 is flashing? If yes, please disconnect the load and run the converter with no load to check if it can start normally.
Also, can you provide us a video showing the normal working state of the converter and its sudden trip protection for reference?
One more thing, when your equipment presses the emergency stop button and suddenly stops running, does this mean that the equipment is overloaded? Please confirm.

ATO wrote:
Can you confirm the maximum in-rush current the 45kva we have can handle before tripping?

Zak wrote:
The maximum in-rush current this 45kva converter can handle before tripping is 62A at 400V, 125A at Low grade setting 220V.