GFCI Problems on a Tiny Houseboat

[Jim Price]

All, Thanks again for your help and advice. Attached is a revision of my earlier wiring diagram with corrections for the errors I made in making the diagram. I actually wired the inverter correctly per its instruction manual, just incorrectly drew up the diagram. Jim Price

 

[fallguy]

The Class T fuse is designed to blow fast for any inrush. The breaker doesn’t even have data I could find on the rate of it’s performance. Class T is the typical thing in a boat.

I don’t understand the reason for two leak detection devices.

I am sorry if I got it wrong. I assumed you knew that all circuits in a boat should be gfci and yours were.

What I might try on your boat is to kill all the power sources. Then go to your AC outlet and continuity test between the ground and the neutral. My hunch is somewhere they are made common node and that is what the air conditioner plug is detecting.

 

[Jim Price]

All, Thanks again for all of your study, efforts, and advice. Per all your advice, I have redesigned the houseboat wiring as reflected in the attached “NEW” wiring diagram. Within the Solar/inverter/battery system, It now has only one ELCB Earth Leakage Circuit Breaker (40A) just before the “black colored” Shore Input receptacle. I am hoping that this ELCB will provide GFCI “like” protection to all of the 120v AC circuit receptacles and prevent dangerous shock current from going into the water around the boat, both, when it is plugged into shore power and when the inverter is powering the outlets while at sea. I have also added a 250v 200A Class T Fuse at the house battery.


I also, redesigned my desired, “always OFF”, Solar/inverter/house battery ByPass system trying to allow me to be able to shut off all of the diagram reflected solar/120v AC LOAD/120v AC GRID/battery circuit breakers, then, move the shore cable to a, second, “white colored” Shore Power Input receptacle and turn on the second ELCB. This, should route the shore power directly, through the second ELCB Earth Leakage Circuit Breaker, to my 120v AC LOAD circuit on the boat. This ought to allow the 120v shore power AC system to continue to power my 120v AC refrigerator and 120v starting battery charger/maintainer, while the boat in not being used and in it’s slip at the lake. This “maintenance style” power system should also prevent any potentially dangerous electrical leakage into the water and provide a GFCI “like” protection at my boat’s 120v AC outlets while the boat is stored in it’s slip. Using it this way, only one ELCI will be operating on the boat and any one time, so I am not stacking GFCIs.


I know I am still asking a lot! I also know that all of you have put forth effort to study my diagrams and research the wiring on my SunGoldPower inverter. I thank you for your time and knowledge. I am ready to wire the boat like my wiring diagram reflects, so, if any of you see any problems with this new design, please let me know. All help is greatly appreciated! Jim Price

 

[fallguy]

An ELCI is not a GFCI.

There is no reason for a bypass. The shore power will keep things topped off and the solar will provide what it can.

On my boat, I have an ELCI on the incoming shore power. I don’t have an ELCI elsewhere, but ALL AC outlets on a boat are GFCI protected. I don’t believe the Inverter requires ELCI downstream from it.

 

[fallguy]

I encourage you to join the Facebook group Solar on a Boat and share your plans there for more feedback.

 

[fallguy]

Peter Kennedy has a nice paper on boats and gfcis and elcis. Of course, you are not tripping the shore power, but it may help you.

Did you check your boat for continuity between neutral and ground?

How to deal with a boat that is trips the dock Ground Fault circuit breaker. - A discussion of the issues and possible solutions https://shop.pkys.com/dock-ground-fault-breaker-trip-issues.html

 

[Jim Price]

fallguy, Thanks. Haven't made the continuity check yet, will do that tomorrow. Also will watch the Kennedy video.

 

[Jim Price]

fallguy, I checked all of my 120v AC outlets and found all to test Correct Wiring and no continuity between the Common and Ground wires. I also, removed my 6,000 BTU window air conditioner and returned it as defective. Ordered a replacement which will arrive tomorrow. Based on ABYC standards and the advice I have received, as reflected on the Newer, attached drawing, I plan to install the ELCI (i.e., ELCB) Earth Leakage CB near the shore inlet and replace the standard 120v circuit breaker between the inverter and the 120v AC outlets circuit with a CGFI breaker. Thus, I will protect against water shock with the ELCI and potential appliance problems with the GFCI. I don't think that this is stacking GFCIs as they are each designed for different protection problems. Sounds like this is the way your boat’s system is wired.


The reason I desire to install the 120v AC Shore power ByPass system, is that I don't want my boat's solar/inverter/battery system to run continuously during the multi-week (& winter) periods when it is not in use (also my docking slip is covered), yet, I want to keep the refrigerator running and the starting battery to remain charged directly off the shore receptacle. If something went wrong in the inverter system while unattended, it might cause a fire or at least, put high usage time on all of the components. philSweet alluded that my earlier ByPass wiring plan was dangerous, so I redesigned it to be completely separate from the inverter system, even with a separate shore input receptacle. If you have any ideas on how better to accomplish this desire, please let me know.

As always, thanks for all of your help and advice. Jim

 

[Jim Price]

All, while employing the 120v ELCB (Earth Leakage Circuit Breaker) (40A) just before my 120v AC Shore Power receptacle, do I also need to install a Galvanic Isolator between it and the shore receptacle, like a Victron Energy Galvanic Isolator VDI-16 Amp, to prevent corrosion of my in-water metal boat parts while plugged into shore power? Jim Price

 

[fallguy]

On my boat, the ELCI is part of the smartplug system which is the plug, the elci and the breaker all from smartplug.

And I am running a galvanic isolater downstream from it.

I think the VDI 16 is probably too small eh?

I am pretty sure you are going to create a ground loop with your bypass switching. I’d avoid that unless you do a 2 pole and disconnect the ground, but it is really just getting so wonky then.

 

[Jim Price]

fallguy, I would still like to be able to disconnect my solar-AIO-Lithium battery system during the long periods when the boat is not being used, yet still keep the 120v battery charger/maintainer functioning. I have asked Sungold Power’s technical staff if; “When I turn off the DC circuit breaker between your 3000W AIO and the solar system’s Lithium battery, your 3000W AIO inverter loses power and shuts down. My question is, within your 3000W AIO’s design, is there an ongoing/continuous connection between the 120v Shore (GRID) input’s earth ground and the AIO’s output LOAD circuit when your AIO is shut down? If so, this would allow the “proposed” Bypass system to function (with earth grounding) and provide 120v AC power directly from the shore power receptacle to my internal 120v AC LOAD circuit to power my boat’s 120v AC wet cell starting battery charger/maintainer?”

I sent them a modified wiring diagram to support my question. It is attached. Am I right, that, if their AIO inverter maintains a constant connection (even when the AIO is shut down) between shore earth ground and their inverter’s 120v AC output’s earth ground, that the proposed Bypass design will work?

You mentioned a “2 pole and disconnect the ground”, what would that look like in relation to my entire solar system’s design?

As always, I really appreciate your taking the time to answer a “Dumb” guy’s questions. Jim

 

[fallguy]

Ground loops are generally bad in electrical design. Whether it matters here or not; I cannot be sure, but it will cause issues in NEMA2K circuits.

In your prior drawing you had a lot of grounds looping about and I can foresee some oddities that way.

The current drawing is better and avoids the need to switch or disconnect grounds. I am pretty tired and not really in the frame of mind to review it. Maybe tomorrow.

 

[fallguy]

I could be wrong, but I think the elcb would be better before the galvanic isolater. Any current flowing from any failure in your system would need to flow through it and the gi allows it to go past it.

 

[fallguy]

Most really good boat designs do NOT use the start battery for any DC loads. Consider you are out for a few days and some DC load was left on, now no start. And most good designs switch the start battery off when not in use. I also added a start battery monitor on my boat for the two starts so I can make sure they are in good shape before cranking.

I have the same challenge as you and have a bunch of 12vdc loads. On my boat, I have dc solid state step downs all over 5amps. I hate them. You want one, not 8.

I also have RBSs onboard. Those are switches that shut the battery off remotely.

My start batteries have a couple DC loads, for the record. They are powering the engine computers and the Orion chargers. The Orions have a small milliamp draw for an led bulb. I did that to avoid running 25 feet of wire and 35’ of wire.. the engine computers are on with the key on

 

[Jim Price]

fallguy, You are saying that the ELCB should be between the shore power receptacle and the GI, correct? I Inquired to the GI Manufacture if my planned location for their GI was correct and they said it was. But, they might not have considered your point. Should I change it’s position?

As you can see, I connected the AIO’s ground connection directly with both the outboard motor (earth ground while on water) and the negative post of the starting battery, should I remove the connection to the starting battery? I also connected a cheap battery status monitor to the start battery so I can see any drop in its potential.

I purposely kept my 12v DC system isolated from my solar/inverter provided 120v AC system. Within the boat, 12v DC powers nothing but the LED house lights from a separate 12v DC Wet House Battery, while all of the boat small drain running lights/equipment/etc. are powered by the 12v DC Wet starting battery and are only required when running the boat. I also, have a 12v DC battery switch allowing me to switch from the start battery to the house battery if my starting battery runs down. My starting battery charger/maintainer for both the house and starting batteries runs off of the 120v AC circuit, hence my desire to Bypass to only shore 120v AC when to boat is dormant. Because my 12v DC LOAD is very small the both the house and starting batteries are charged by the outboard, I haven’t seen the need for any “to” 12v step down transformers.

Do you think my newer plan to wire in an “Always OFF” 120v AC BYPASS system will work OK?

I disconnect the inverter system from the Lithium battery using a 2P-160A circuit breaker, only when I am shutting the system down. Do you think I need any form of remote RBS (?)?

As always, thanks for reviewing my designs and providing me with your advice. I believe I am learning a lot from this forum. Jim