From what you've done it does seem like you've assembled the capacitor bank properly. So with a properly assembled package that repeatedly fails, this leads to only two other options, poor design or operation control. Both options require more information like a schematic, operational signal measurements and verification that the actual assembly is being used as the designer intended. In other words, a knowledgeable person on site to troubleshoot your repetitive failures.
Now if I was there, the first thing I would do would be to verify that the schematic agreed with the actual circuit assembled. Next I would measure the currents running through the circuit breaker and capacitor bank with a clamp on ammeter and oscilloscope. Then and only then might I have a suggestion which might be your cause of failure.
"Don't disturb my circles." translation of Archimedes last words
"Success is not measured by what you accomplish but by the opposition you have encountered, and the courage with which you have maintained the struggle against overwhelming odds." -- Orison Swett Marden