Fran, we are having a similar day.
2nd washer delivered and set up. They started it, worked fine, they left and it tripped the breaker. I am doomed with washers in this new place. Guy just installed the outlet and obviously did a poor job. It trips every time I start the washer.
I wonder if the guy that installed the outlet checked to make sure the circuit breaker is sized correctly for the washer or is it a GFCI receptacle that is tripping? If it's not a GFCI and the breaker is tripping then there could be other things running on that circuit or the breaker itself might be weak and need replacing. I've seen that happen before.