Random tripping at house DB not at complex DB
You probably need to submit more detail to get a complete answer to your problem, but I will try and answer from the information you have given up to this point. 

First I can't think of a situation or reason how an problem upstream would trip a downstream breaker. So the trip would occur at the main distribution area or just fault out or burn up at the original damage. 

Second the you need to have an ammeter and check the amount of current flow at the breaker tripping in house DB. 

Now here are some questions you need to answer to get further information.
Which breaker is tripping in house DB?
Is it the main or one of the branch circuits?
Did you have breakers tripping before the repair?
How old is your system?
Has anyone tested the voltage at each phase and the neutral to ground (disconnected)?

Hope this helps