I'm thinking of adding shore power
to our dear "Pelican", a 33 foot sailing boat.
She currently has two, older, 50 watt solar panels charging
a bank of 4 Trojan T 105 batteries through a PWM controller. I plan to increase the solar
to perhaps 200 watts or so at some point before taking off on longer cruises. I'm pretty sure I can keep the total load low enough for this to work for us.
Pelican has no inboard engine
. We start the Honda
"Herki" from the house bank (or use the pull starter). Herki delivers 10 amps to the house bank when we are motoring in/out of the slip - perhaps an hour of motoring each week on average.
This setup pretty much meets our present needs (mostly weekend use plus a few one to two week long trips per year) - and has kept the batteries topped up for the most part (rarely dropping below 12.7 volts under a few amps load and often charging
with Herki at 14.4 volts or so).... but lately, it has been cloudy and voltages have been as low as 12.4 so, for the health
of the batteries, I'd like to be able to get a truly full charge on a regular basis when we are in the slip, and even run equalization
on some interval as recommended. A time or two, I have run an extension cord and used a car charger
to top up the batteries at the dock
, but I understand this is a dubious practice.
I have a FleetPower 1000 charger/inverter that I'd like to use to charge and maintain the batteries. There is a Link 1000 battery monitor
already installed that can interface with the FP 1000. This setup offers an equalize function of some kind.
It seems that all I need is a 30 Amp shore power
connector, and a proper marine
AC main distribution panel, plus correctly sized marine
grade wire and connectors and a proper install - and maybe a galvanic isolator
. I already have the cord.
I feel pretty confident up to this point - but I am still at a bit of a loss about grounding. I've done a fair bit of reading and everything I've seen says to tie the AC 'safety' ground (green wire) to the DC ground at the inboard engine
(and hence to sea water
through the prop shaft). Of course, Pelican does not have an inboard engine - so where to tie the AC and DC grounds? Or should they be tied together at all?
Also, is a galvanic isolator
even needed in this instance (no connection on the boat between sea water
and the electrical
The only metal below the waterline on Pelican are the stainless pintles/gudgeons for the rudder
and one bronze through-hull. There is a zinc on the rudder
- and one on the outboard
. In 1.5 years, there has been little wear on the zincs. The outboard is never left in the water when not in use.
Thanks in advance for all comments, insights or advice.