We have a well-equipped 1998 Sea Ray 310 Sundancer purchased 3 years ago. All electrical devices have operated perfectly until this year. This year our municipal marina installed new GFI power pedestals, then our problems started. Some electrical devices operate fine. But when we turn on the air-conditioner or the microwave, the 30 amp breaker on the pedestal trips off instantly. A marine electrician has inspected and tested all our circuits and wiring and found no problem. We have tried other shore power cables, and have plugged into other pedestals, without success. Any suggestions?