Hubbub

The new shore power inlet is installed. Deciding the placement was difficult. It needed to be close enough to the service panel to avoid the requirement for additional circuit breakers. Placing it on the cockpit exterior would have interfered with rigging. Through the cabin top would have been ugly with no way to conceal the back of the inlet or the large electrical cable.

The coaming interior near the cabin bulkhead was the best compromise. An existing cutout in the cabin top provided good access to the coaming interior. This facilitated installation of backing plates and reaching the back of the inlet to tighten fasteners.

David made the cutout in the fiberglass with a two inch hole saw followed by a Fein Multimaster. We connected the three 10 gauge leads to the back of the inlet and inserted the inlet into the cutout. I held the inlet and its four screws while David reached inside the coaming to fit the backing plates and nuts. A couple additional 1 inch holes were needed through bulkheads to lead the cable to the service panel.

From that point, the plan has changed since my last post. I decided to abandon the isolation transformer after learning that it produces significant buzzing noise. Also finding a suitable location to install it would have been difficult considering the transformer’s cooling and clearance requirements. Instead I returned to using a simple galvanic isolator.

The isolator fits conveniently through the cabin top hole and is located inside the coaming (still needs to be secured properly). The isolator is connected at the panel rather than inline at the inlet for ease of access. Wires are connected to the isolator leads and incoming ground lead using butt connectors that are crimped and protected by heat shrink tubing.

The new AC leads are temporarily connected to the existing AC panel and ground bus to provide usable power on the boat while waiting for the new AC panel to arrive. Theoretically this setup should work as before but with a safer connection to shore. However, after 15 minutes of running the battery charger and a space heater together something in the panel started producing a buzzing sound. The sound could have several possible causes including arcing, a breaker (or the main) close to its capacity, or a breaker gone bad. In any case it’s a sign that the old panel is not to be trusted.