Charger install Q

Hello - this is my first post here, and I hope this is a simple question but not a stupid one: I am spending the off-season planning an upgrade to my electrical system. One start battery and one 115 AH house battery, no AC, minimal consumers on board. Currently there are no breakers or fuses at all until you hit the small distribution panel. I will correct that deficiency, and add a Blue Sea ACR/Switch but in the meantime I am planning the installation of my new Promarine 12A dual-battery charger.

The charger power cord has a 3-prong plug attached, and the + leads to the batteries each have an inline fuse. The 15A AC outlet on the dock pedestal is GF protected.

My plan is to simply install the charger power plug into a fixed inlet on the side of the boat, and plug the AC power into it when docked. I have been advised that I need to install a breaker between the extension cord and the charger plug. My question: is this really advisable? And if so, how would you do it?

 

I would use an extension cord rated for 15 amps and then let the breaker on the shore outlet protect it from overload. I'd make sure that the shore ground didn't get tied to anything else on the boat. But I have no idea what the standards say.

 

Well of course the shore ground is presumably connected to the charger by virtue of the 3-prong connection, no? Which I assume is to ground the AC side of the charger. Or do I have it all wrong in my head?:?:

I have been studying up on 12V principles but have tended to skim the 120V stuff since I have no intention of going there, except for the charger.

 

Do whatever suits you best, just make sure there is no electrical path between shore ground and the on board DC ground. If the charger internally connects these two, cut the wire.

 

OK, I'll try to determine that but I imagine it's unlikely that Promarine would construct its chargers like that.