Long wire runs often cause nuisance tripping of GFCI circuit breakers.
I have a problem understanding this sentence. Particularly, the part that's in bold. Long wire runs are what makes GFCI circuit breakers trip (malfunction). That's how I understand it. But I don't see why we need that of there. Why not just say, "Long wire runs often cause nuisance tripping GFCI circuit breakers"?