a) Problem description: We connected our backupbox and it did not work. It seems as if the contactor is having trouble and not functioning correctly. We dettected this due to the noice it was making and how it keep trying to enter.
In order to show you the problem to Huawei support team we attached a video that showed the measured voltages in the coil and the contactor sound. This was in order to know if it was a problem with the contactor or the functioning of the backupbox.
b) Problem Analysis: After checking the voltages, the connections with the user manual (photo attached) and the logs, we proceeded to open a case with huawei technical support team. We recieved the following images to understand better how the components were connected and to know if they were working properly.
c) Cause: The main cause was that the voltage in LA is 220 Volts between Line to Line cables and the backupbox works with 220 Volts between line to neutral cable. It has a voltage missmatch detection system which triggers when one voltage is lower in one phase than the other. Having 220V between both phases caused this detection system to avoid the backupbox from working.
d) Solution: remove the differential as you can see in the image below. This way the trigger actioned by the voltage difference would not actioned and can avoid unnecesarily actioning that would stop the backupbox from functioning.
The bridge that connects the physical earth with the neutral earth must be removed (in 220VAC L-L systems is a line) the cable can be disconnected from both points to secure the bridge (11).
If the problem persist you have to disconnect the contactor cables and measure the resistance between A1 and A2 and contact technical support of Huawei to see the main problem and find the solution or apply the warranty of the backupbox.
