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Inverter connection and shore power

DGA

DGA

Member
I'm adding a 1500 watt inverter to my 382, and wonder how others have done it. The boat seems like it has all it's original wiring and hasn't been hacked much, if at all. Power into the inverter seems simple, basically two battery cables to the batteries in parallel, although I have not looked at how the main switch handles one or two batteries.
Aside from that major detail, and not being able to provide inverter specifics here, is it normal to disconnect the inverter when going on shore power? Like, unplug the 110vac outlets to the boat before connecting shore power?
I'm worried that the shore power will backfeed the inverter; send it 110 vac to it's outlets. Or do some just switch the inverter off?
Once I go back to work on it this weekend, I can study the wiring in detail, but trying to get a basic plan in my head before I go, possibly buy more items that it might need for that.
 
If like you have said, the boat has all the original wiring, I would spend some time investigating the 110Volt system. When the boats were built the shore power system was a flimsy affair that was not up to any standard of quality or safety. It isn't even close to today's ABYC standards. The first thing to inspect would be the disconnect switch that the builder located behind and under the aft cockpit coaming where you cannot get to it. If that switch is the original, it is probably a ball of rust and must be replaced in a new location where there is access. So before you begin to add new equipment, bring the 110 Volt system up to snuff.

Jim
 
Is that disconnect switch an automatic device? It all seems to work ok as is, not saying that that switch isn't a rust ball, but it is working now. So, to work on something, you first must understand how it works. We plugged the shore power in and it showed 110 vac at the outlets, once I found the mains switch for that, and were able to use a 110 vac battery charger to charge the two batteries. Oh, the original charger is still on the starboard engine compartment wall, at least the boat yard owner said it was original, and I probably need to remove that too.
This boat has been hooked up to shore power a lot over it's life I think, it had so many 110 v appliances on board, two microwaves, a big electric griddle, coffee maker among other items.
 
There are a lot important small details with an inverter installation. As Jim stated, the very first thing is to make sure the existing is safe. The disconnect Jim is referring to is a standard household circuit breaker, in a residential square D box, in a very difficult to get to location right behind the shore power connector. It is not designed for a marine application, so if original is surely in need of replacement. It should be updated to an ELCI type breaker. Then, everything else need to be checked for corrosion. A small amount of corrosion on an AC power connection can create a lot of heat and start a fire. Given the age of the boat, if the wiring is original, every connection at every outlet, and at the breaker panel etc. is suspect. The power socket on the stern probably needs replaced, and many recommend using a higher quality "smart plug" instead of the NEMA twist lock. So, all of that needs to be carefully checked. If checked and confirmed good, ok. But if it's original it probably isn't.

You will also need a functioning reverse polarity lamp, and should install either a galvanic isolator or isolation transformer.

To answer your question, a couple things need to happen with the inverter. You cannot have both inverter output and shore power active at the same time. That isn't as simple as unplugging the inverter, as if you forget one day to do that, you could start a fire or die from electrician. The inverter and shore power need to go to a change over switch to switch from shore power to inverter power., such that it is impossible for both to connect to each other. There are switches specific to this.

The other important thing is the ground/neutral connection. On your boat, AC ground (green) and neutral (white) should not be connected together while on shore power. However, they must be connected while on inverter. On inverters that are designed for boats, this is done in the inverter with a relay. Such that when the inverter is turned on, the relay closes and connects neutral and ground. And when the inverter is turned off, the relay opens. If permanently connected, you could create a situation with excessive corrosion. If permanently open, you create a safety hazard. So, it is important that when you source your inverter you buy a quality unit that is designed for boat use.
 
All makes good sense. I'm fine with having to switch from shore to inverter manually, so will get a 3 pole manual change over switch and install it close to the main battery switch. I'll look for the breaker in the aft engine room area and pull it and replace it with similar for now. This work trip is to seal off any possible sea (lake) water intrusion, the last trip was to seal off rain water problems. So I have to go in the engine compartment, oil change and packing seal replacement, so I'll look for the shore power breaker while in there. There isn't much corrosion on anything I have seen yet, I know what salt water does to anything metallic, and this is a lot better off for sure, nothing looks bad in that respect.
 
That switch, which is inside the coaming directly behind the shore power entrance fitting, is a cheap homeowners Square D affair. There are no fuses or circuit breakers involved. If yours is still there, you need to revamp the system. It sounds like the previous owner depended a lot on shore power, so you may be lucky and it will have already been redone.

Jim
 
That switch is not in the engine room. It is up behind the coaming at the back of the cockpit with access through what we call the wheel locker (Where the steering quadrant is).

Jim
 
Mine was indeed a Square D breaker, but maybe it had been replaced at some point. The location is not in the engine room, but mounted just behind the shore power socket, accessible from the cockpit helm locker. It is accessed by entering the locker head first, and on your back, and wiggling until you are almost entirely in the locker. Teaching a 15 year old how to work on electrics might be the easiest route to replacement.
 
As said it is a real pain to access. Literally painful. If you're small enough to even get there. I found it a good idea to have someone else there to help extricate you from the abyss.
And thanks to Jim and his technical widom;
My next trip to Sonata will be replacing the breaker/box, and replacing it with a Blue Sea ELCI breaker, reverse polarity switch in the 1/4 berth as other members have.
Mitchell
 
The ABYC allows the disconnect switch to be six feet from the shore power entrance fitting. That would make the aft end of the quarter berth as at the best place for a relocation. It would also allow the switch to be accessible for service and in the case of emergency.

Jim
 
I have trouble negotiating nautical terms a lot, I'm getting there, but.... Cockpit helm locker, is this under the helm seat? Mine has a, I think, later model curvy seat, on top of a plywood cover, under that, I'm not sure. I lifted it off once but don't recall what was in there. I'm small framed, so shouldn't have big issues going down there.... I hope. To be sure, this isn't in the aft anchor locker, correct?
 
Not trying to be a smart a@@.
Shut off the shore power at the dock or wherever. Unplug the shore power cord from the boat.
Open the helm seat hatch, tie it open so not to fall on you. It will otherwise.
Climb in, laying on your back, feet out on the seat. Reach up into the raised coaming, feeling for the box where the A/C shore power enters.
I found it nearly impossible to see the box when I replaced a breaker and added a galvanic isolator there. All by feel.
You may be able to see it from the outside if you remove the shore power inlet receptacle and peer through that hole. I'm not to big either, still its difficult.
Your milage may vary!
Mitchell
 
I found that I could see and reach it pretty easy if I got almost completely in the locker. So the box was about even with my shoulders, and right in my field of vision. The difficulty with this is that because of the shape of that area your rear end will be supported on the cover for the quadrant, and your torso to your shoulders will not be. So it's like doing a crunch or a leg lift and holding it the whole time you are working. It is a serious workout and you will feel it in you abs afterwards.
 
Well, I could barely see mine, but I have the auto pilot on the starboard side in the way of moving that direction I guess. Yes, quite a workout. And I found it hard to get outta there.
 
So this is also the access to the rudder cables and rudder packing? If so, yet another thing I need to inspect and probably repack. I also intend to fit my own design of a wind vane or hydro vane later on, and would like to not run lines around the cockpit to the wheel, rather, go straight through the transom in a cleaner, neater installation, so this would be the access to all that. Good.
 
To find the A/C switch I would suggest to use of a medium sized mirror first. In and up behind the helm seat look up to where the A/C inlet fitting is on the outside of the coaming. That will give you the knowledge of where the box is and if indeed it exists and if it needs replacing. If that inspection confirms what is or isn't there, then you will have to begin the gymnastics to get in and remove it. If the box/swithch is there, it is the weakest link in the system and needs to be gone. If you are going into the locker, follow Mitchell's advice and tie the locker hatch open before going in. On our 1978 382, we are almost never at a dock so we removed the 110Volt system completely and only have a full syne wave 600 watt inverter for charging phones and stuff.

If you are interested in installing a vane steering system on board, you might look at the Monitor system. It is an independent system which requires no lines or cables to the steering gear and can be mounted off center so you don't lose the stern ladder. Of course that is just my observation, others will have different opinions.

Jim
 
I am planning to upgrade the breaker to an ELCI breaker with galvanic isolator as well. After I bought the boat 2 years ago, I went into the aft cockpit locker to inspect the shore power plug which i replaced with a smart plug. Ripped a good pair of jeans and received a few cuts getting in and out. Not somewhere I want to go regularly. I will likely install the new breaker in the quarter berth, but has anyone considered or actually moved the shore power inlet closer to the panel location along the starboard side so the breaker could be near the main panel but still be ABYC compliant?

Thanks
Jack
 
On the self-steering. I have seen many homebuilt systems, and they all sort of worked, but none as well as a good name brand system. AFAIK, there are only 2 options. A Monitor, or a Hydrovane. Both are represented by owners on this forum, and you can get lots of information from us on them. I own a monitor, it works incredibly well, but has some downsides. The Hydrovane also works well, and Hydrovane owners love them.

The monitor is a servo pendulum type with lines to the wheel, and the hydrovane is an auxiliary rudder with no connection to the wheel that also serves as an emergency rudder.

I have seen installations with lines going through the transom. I've looked at how it would work on our boat, and I think it is a bad idea. For the lines to route under the cockpit floor, the holes would sometimes be underwater.

Anyway, start another topic when you get to working on the windvane. We can share a lot.
 
jniemczuk said:
I am planning to upgrade the breaker to an ELCI breaker with galvanic isolator as well. After I bought the boat 2 years ago, I went into the aft cockpit locker to inspect the shore power plug which i replaced with a smart plug. Ripped a good pair of jeans and received a few cuts getting in and out. Not somewhere I want to go regularly. I will likely install the new breaker in the quarter berth, but has anyone considered or actually moved the shore power inlet closer to the panel location along the starboard side so the breaker could be near the main panel but still be ABYC compliant?

Thanks
Jack
Click to expand...
I have thought about it, but I have also buried the rail in the water on several occasions. I would not want it to ever be submerged. I'm not sure where a good location would be. Perhaps within the cockpit itself if that doesn't bother you or get in the way.
 
Warren

the hydrovane must be the system I was thinking about. An vane independent of the boats steering gear. That makes a lot of sense to me.

You are also correct about the shore power fitting on the side deck, not a good place.

Jim
 
There are issues with any self steering system. I have a Monitor. If you go on the Scanmar website, you will see some Morgans with Monitors. I sent them pictures, I thought, but my boat is not shown. My lines go through the cockpit rather like, but not identical to the boats shown. I would discourage going through the transom. The measurements won't work.The two lines are not a problem for us and there is not room. Anyway, you don't want the lines where you can't easily get to them. Only system I know that seems to go through the transom is the Cape Horn models. Pricey but highly regarded, I think. J especially like the new monitor emergency rudder system.
 
My self steering design has a rotating shaft run through the transom, that has an arm that somehow connects to the rudder quadrant, or whatever is in there. But as you said, I will start another topic on that when I get to that point. Many, many more important issues to deal with first.
 
Here is the Cape Horn system. http://caphorn.com/en/how-capehorn-makes-boats-steer-themselves/
My aft cockpit locker is too important for storage (extra lines, stern anchor line, shore tie lines, emergency tiller, etc, etc), for me to give up the space for a self steering mechanism. Also, the 382 can be a little squirrelly with the wind abaft the beam (her one significant flaw in my view), so the self steering has to be powerful. The best for her might be the old Auto-Helm auxiliary rudder, which puts the steering rudder an extra foot astern. But they also have downsides. (I know some like the HydroVane, but when a manufacturer tells me that I might want to use an electric auto pilot to "help" the wind vane, I run the other way.) Each to his own.
 
I used the Monitor EmRud to steer my boat with the original rudder removed while the new one was being built for 150 miles back and forth under power on the Sacramento river. Did just fine.
 
I went down in the helm locker and looked up at the breaker box in there. Aside from being grubby looking, it's decent, no rust, not an issue at all. Remember, this is a great lakes boat, no salt, and sits on the hard for over six months of the year.
I replaced the prop shaft packing, not hard to do, and now the shaft has some drag feel to it, so I'm betting it would have been leaking as it was. Changed the engine oil, I let it drain a quart or two into the fiberglass drip pan it has under the engine from the NPT drain plug on the front of the oil pan. I don't think you can get the last quart out because of the engine tilt towards the aft, bit I got 4 quarts out. Was pleased to find the oil filter is on a remote mount and hanging down, at the back of the engine, so it wasn't too messy and I was able to pre fill the filter.
Got the vee berth cleared out and the hatch opened, zero seal remaining on that so I have a replacement for it today to add. Looks like rain here just north of Detroit today, so I'll have to do all the inside tasks, got to fit a new vhf uniden radio and some more cleaning. So much to do.
Oh, the hull number is #152.
 
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