Installing New Inverter - Do I connect the Ground?

[rslifkin]

Originally Posted by Davidla

One other thing I forgot to mention in an earlier post. Best practice seems to be that inverter AC loads should have a separate neutral bus from shore power Neutral loads. Makes sense given the use of ground to neutral internal in the inverter when not connected to shore power. This happens as part of the auto transfer in my victron at least.

Yes, you'll need to separate the inverter neutrals. Otherwise you'll have an issue with any dock with GFCI breakers. The inverter will still have neutral and ground bonded for a few seconds after you plug in (before it transfers), so if the neutral is shared, the GFCI will trip.

[StoneCrab]

My thought on the vocab discussion related to external stray currents is that it is splitting hairs for no practical benefit.

You add zincs as a sacrificial metal to protect the disimilar metals on the exterior of your hull, but you add a bonding system to keep all those bits at the same potential so that the sea water doesn't become the conduit for stray voltages.

If one of your thruhulls is at a higher potential than another, one of them will soon disappear, regardless of what name you put on the process.

We can also have a lively discussion about which direction electricity flows and whether the current and electrons are going in the same direction, (they got it backwards by the way in the literature) but when the hull hits the water, all that matters is wether you are properly bonded and your circuits all have appropriate return paths.

[Davidla]

Electron flow versus conventional flow - got it. Electrons go only from negative to positive.
The currents generated by (internally generated) electrolytic corrosion will have a voltage flowing from the component connected to the 12v circuit. It will shed electrons and thus metal ions and become the anode regardless of its makeup. More than likely any zincs nearby will be unaffected. I can quote the Catalina 350 owner whose rudder fell off because of an accidental 12v connection to it via the helm pedestal. It did not take long and the owner did not detect it via battery drain.
I own a Catalina 350 and have all plastic through hulls and no bonding system. I keep a close eye on the wiring in my steering pedestal.
There are two zincs on my vessel, one on the prop and one in the Heat Exchanger.

[rwidman]

Not to be a smart ass, but you should follow the instructions that came with the inverter in regards to connecting the ground. Now if it's an inverter from Harbor Freight or some such and not intended for marine use, that's going to be a problem.

The National Electrical Code requires that the be a ground for AC circuits and it also requires that the ground and neutral be connected together at the source (of power). When your boat is connected to shore power at a marina, that "source" is the marina's electrical panel. Ground and neutral are connected together there.

Once your boat is disconnected from shore power, if you have an inverter, the neutral and ground are to be connected together at the inverter.

The problem arises when you return to shore power. The neutral to ground connection at the inverter must be disconnected while on shorepower.

A proper marine inverter with a proper transfer switch (either automatic or manual) will take care of this.

Again, the answer to your question will be found in the inverter installation instructions. If it is not, contact them and ask. Or have a marine electrician look over your installation and make any needed corrections.

[StoneCrab]

Originally Posted by rwidman

HIGH Cotton

I've got to know

[smac999]

Originally Posted by Davidla

One other thing I forgot to mention in an earlier post. Best practice seems to be that inverter AC loads should have a separate neutral bus from shore power Neutral loads. Makes sense given the use of ground to neutral internal in the inverter when not connected to shore power. This happens as part of the auto transfer in my victron at least.

If you don’t you will blow elci / gfi main or dock breakers.