Installing battery charger

[Tom in Ohio]

I have a Xantrex truecharge 10TB that I want to install to run off shorepower. I have very modest electrical needs: engineless, nav lights, instruments, instrument lights, VHF, cabin lights, cabin fan. I have no plans, at least now, for any AC power except the charger.

I know I have to wire the shorepower connector to an AC panel with a bi-pole breaker for hot and neutral. I'll then wire that to the charger.

My question is what to do with the green wire (ground). Should I run it straight from shorepower to the charger, or also run it to the common ground on the boat?

My reason for asking is this: If I run the green wire to the common ground, I'll now have to worry about galvanic corrosion (although I am in fresh water). If I don't, the charger itself works as an isolation transformer, so the only chance of electrocution would come from the charger getting submerger while connected to shorepower (although the shorepower cable and AC panel would all get submerged as well).

What should I do? Just wire the green wire to the charger? OR wire the green wire to the common ground and also wire in a galvanic isolator? Obviously the galvanic isolator gives me room for future expansion, but for my modest needs is it worth the extra cost?

[Ryan]

The main reason for connecting the AC and DC ground is to provide protection in the event that the AC hot line shorts to the DC side of the charger (an internal fault on the charger). Should this happen, then the boat's DC system is energized with AC power and if the grounds are not connected, the AC breaker will not trip and the DC system remain energized with AC. Connecting the two grounds will allow the AC breaker to disconnect if this happens.

You are correct that connecting the two grounds can leave you susceptible to galvanic corrosion, but a galvanic isolator will take care of this. Are all your through hulls bonded? If not, and you have an engineless boat, you shouldn't have any underwater metals to be concerned about anyway, correct?

Tie the grounds together and install an isolator and you'll be set for anything else you add down the road.

Ryan

[Rachel]

Hi Tom,

Welcome to the forum!

Rachel

[Tom in Ohio]

The only below-the-waterline through hull I have is the knotmeter - the only etal part on that is a titanium pin. The only other piece of metal I have in the water is the keel (lead). With this in mind, do you think I can forego the galvanic isolator for now? Again, I'm in fresh water.