Shore power is the part of a boat's electrical system with the most potential to hurt someone, and the part most often extended informally over the years.
These are the faults we see most, and what each one is usually telling you.
An immediate trip generally points at an earth leakage path on board rather than an overload — a water heater element, a failing charger, or damp in a connection. Isolating circuits one at a time and re-energising identifies the offender without guesswork.
A delayed trip is more likely to be a genuine overload, a marginal cable run heating up, or an element degrading as it warms. Measuring actual current draw against the supply rating usually settles it.
Polarity warning indicators exist because marina supplies vary, including abroad. An indicator that lights is telling you not to rely on the installation until the supply and the on-board wiring have been checked.
Connecting to shore power ties your boat's earth to every other boat on the pontoon, which can drive galvanic current through underwater metals. Galvanic isolators and isolation transformers address this in different ways, and which is appropriate depends on the boat, the metals involved and how much time she spends connected.
No. An RCD trip indicates current leaking somewhere it should not, which on a wet boat is a genuine shock risk. It should be diagnosed, not reset repeatedly.
It is worth assessing for any boat that spends significant time connected to shore power, particularly alongside boats with different underwater metals.
Yes — testing and inspection of the AC installation, including protective devices and earth arrangements, is routine work for us.
Supply arrangements and protective device sensitivity differ between marinas, so a marginal on-board leakage can show up at one berth and not another. It is still a fault worth finding.
AC faults are worth getting looked at properly. Free assessment at your berth, written quote before any work.