Adding a 120v outlet

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Guys, I'm thinking of adding an exterior 120v 3 prong outlet to the exterior of my boat to give me more AC wattage inside. Then I could connect an heavy duty extension cord to a shore power outlet adapter and have some more juice inside.

I currently only have 30A of shore power now. I need the extra wattage for the cold months ahead since I'm a fulltime liveaboard now. I don't wanna overload my AC system (even though each AC outlet has a 1500w breaker). All I'm looking for is just to gain a little more wattage. Not a lot!

It seems that adding the 120v outlet would be the simplest fix for my needs. Ideally I would like to have twin 30A shore power cords but that will require a big modification to the wiring, breakers and panel etc.

I also thought of just running an extension cord inside the boat but that's a sloppy way of doing it.

Any ideas? I'm gonna be doing this ASAP......
Use 20 AMP fixtures instead f the 15 AMP
 
Thanks for all the replies guys. Lots of good points for me to process and review until my mechanic comes next week (actually a retired electrical engineer).

I can't reply to everyone but here's a few short responses.

1. When did I say anything about saving a few bucks (ie; cutting corners)?? I've spent over $18k in this boat since buying her in August of 2017 in canvas, electronics, service work and countless other mods. :) My initial reasoning for going this route was only because my boat is for sale and I didn't wanna be doing any "unnecessary" work. But obviously if what I proposed was a safety hazard then I wouldn't have done it. That's why I called a professional a few days BEFORE I even started this thread and scheduled a meeting with him but still folks are trying to villainize me. Lol

2. If adding a 2nd 30A outlet is what we decide is the best option next week then so be it. Safety has always been at the top of my list. That's why I added an EPIRB and a AIS transmitter/receiver this past summer.

3. Portage Bay, PSneeld and other liveaboards: Thanks for your insight. Good to hear some first hand reports from fellow liveaboards who can actually relate. This is my first season! I've been full time since late September. Learning more and more every day.
 
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Thanks for all the replies guys. Lots of good points for me to process and review until my mechanic comes next week (actually a retired electrical engineer).


Jason, good on you for pursuing your objective with some research in determining the safest approach. Just a comment on qualifications- not to impugn your mechanic's qualifications, but... a qualified EE, retired or otherwise, doesn't automatically possess the specific background/skills/knowledge needed to execute a marine installation that meets ABYC standards. It's a specialized field, and an ABYC certification indicates that the holder is qualified to complete the work to ABYC standards. That's not to say at all that an EE can't do a perfect job, but the EE qualification doesn't necessarily trump the ABYC technician qualification.
 
Update: I had a long chat this morning with the professional. He told me my idea COULD be done safely but we decided on going in a different direction for many reasons.

He's gonna install a 2nd 30A Smart plug shore power inlet and I'll buy a Smart cord too.

He's also gonna add a new 30A breaker for the new inlet, a 2nd galvanic isolator and high gauge wiring.

This should be the best setup for my boat and power needs this winter. It'll be a nice addition for whoever buys my boat too. :)
 
Be advised that most boat fires occur during the winter months when using temporary heaters. They are caused by electrical systems which have been poorly maintained, wrongfully installed or were never properly engineered.

Suggest you befriend a certified marine electrician, buy him/her coffee/drink and get a qualified recommendation for your specific needs, boat, mooring location and budget.

IMHO, there are too many variables with far too much risk to have this resolved by a forum discussion.
 
One thing for sure , regardless of the power install is to be sure the heating device is secure.

A pet , big foot or boat motion should not allow a heater upset.

Our current choice is for one of the smaller but pri$y ceramic cube style units.

Te best will pump out about 500W of heat constantly and the thermostat adds another 1,000w as required.

As winter is cooling the boat 100% of the time , it makes sense to provide some heat 100% of the time.


https://www.amazon.com/Comfort-Glow...543666975&SubscriptionId=AKIAJO7E5OLQ67NVPFZA
 
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FF: IMO, ceramic heaters are not the best choice for boats for EXTENDED use. The hot surface can potentially burn something. I only use oil filled heaters. They require less wattage and the surface will never get hot enough to burn anything.

The downside is that they don't put out as many BTU's and take longer to warm up but are much safer for long term use.
 
This is an interesting topic, but as someone said, not for a non-marine-electrical mechanic to fool with.

Did, whoever started this topic, consider that there may not be a 3rd receptacle on the dock to utilize? IF there was a 15A household 3 prong receptacle additionally on the dock do you know that connecting to that wouldn't blow everyone's breakers on your dock? You'd become a very disliked neighbor very quickly.

Let's first get the terminology as I see it.

The requester has 2 -30A inlet receptacles on his boat. Probably Marinco twist lock versions. As an aside if they are the Marinco version, take some money and swap them out for Smart Plugs, both receptacle and cords. 1 is for the house, the other is for the AC. He fails to mention, that I read, how many and what kind of AC units he has.

My first question would be is he sure that the AC units, unless they are of the big box store variety, that they aren't reverse cycle units? Built in to the boat originally. I know ours is. IF they are then his question is answered.

I'll proceed presuming that they aren't.

IT then sounds like the wants to bring an additional 30 service into the boat, that he can use to run space heaters in his boat.

I would suspect that he understands the potential for creating a fire in his boat which of course has the potential to cause a dock fire which will impact not only him but others on the dock. VERY BAD outcome.

Using my own boat as my experience and since we don't know, as this often happens with people in general explaining things, there are huge gaps in the question, what boat he has and how it is configured, other than 2-30A inlets.

It is my supposition that the boat configured and built like it is could handle space heaters. What is necessary is some 'balancing' of his usage.

When connected to dock power it is presumed that there is 30A of power available and that may NOT be the case. Even for 1 inlet. A clamp meter would let you know how much power is available from each dock side outlet. Also, even if at a specific time there might be 30A available to his boat, IF another boat were to turn on a space heater (or other high amperage item) that may pull available power on that specific dock down as to the total amperage available. You might want to check with someone in the marina as to how the docks are powered.

IF you didn't want to go that route then the next best thing, and what you still may need to do anyway, if there is 30A available or whatever is available, is to turn everything off on the boat when connected to the dock, grab a pencil and paper, and start turning on items in a process of how you would be living on the boat.

IF say you wouldn't be using the MSR, then make sure ALL is off there. IF you want to keep it a little habitable, then turn on heat here but turn it down so the heater isn't cycling very often. IF your boat breakers or the dock side breaker doesn't trip as you start this process then turning more on, KEEPING track of what you are turning on.

The idea is to make your boat as livable as you normally would like it before a breaker is tripped.

At some point the 30A house breaker will trip and you can check your paper to see what you have on. Adjust from there. You can't have everything on the boat turned on at the same time. IF you think you should be able to you are being selfish and unreasonable. 30A is 30A is 30A period.

THIS IS A BOAT, not a house. The power into your house is a much higher amperage.

Once you have your paper you can mix items which are on.

You may find, as an example, that you can't flush the head, while you are watching TV, based on the other items you have turned on. IF SO, turn something else off while you are watching TV, just incase you might need to use the head.

We balance the use of the toaster with the use of the microwave and electric skillet. Usually at Sunday breakfast time.

Handling your boat electrical wants & needs conservatively keeps your boat safe and you a hospitable neighbor.

Forget any additional wiring, you are just asking for headaches as to keeping everything in order and NOT starting a fire because you go out and forget to make the necessary modifications before you leave.

Good luck and be smart.
 
Guys,
We had the fire marshal visit our marina in NC when the issue of extension cords came up.

He said
"extension cords are only for temporary use when someone is present"
" they are not to be left unattended"
The only correct method is approved cords and inlets

Anyone can disagree but that is what the fire marshal said.

Bill
 
Yep .....nobody ever uses them otherwise and in almost every case a fire erupts.

Did anyone tell him a shore power cord is nothing more than a big extension cord?
 
I deal with a couple of marinas who are getting more careful about the boats they accept. All slip applicants must supply a current survey with their application. Often these marinas find the survey reports ..... shall we say, inadequate. When they receive a survey report they consider inadequate, they hire me to do safety inspections (not a full survey) prior to approval for a slip.

Some members here find my comments a little harsh but take a look at this inspection report (one of my favourites) of a vessel that applied with a survey report that recommended little more than pfd's and fire extinguishers. I see this kind of thing every week. No doubt it has jaundiced my opinions.
 

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Wow, what could all of those extension cords possibly be powering?? Please don't let that boat dock next to me:hide:. I know the spare propane tank in the 'basement' is a no no, but consider all of the exchange propane tank racks at gas stations mere feet from the gas pumps. As long as they are sealed, and no valve attached, they are very safe.
 
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FF: IMO, ceramic heaters are not the best choice for boats for EXTENDED use. The hot surface can potentially burn something. I only use oil filled heaters. They require less wattage and the surface will never get hot enough to burn anything.

The downside is that they don't put out as many BTU's and take longer to warm up but are much safer for long term use.



The other advantage is that the heat is a bit more consistent. I think they are a great alternative for a live-aboard situation.
 
Wow, what could all of those extension cords possibly be powering?? Please don't let that boat dock next to me:hide:. I know the spare propane tank in the 'basement' is a no no, but consider all of the exchange propane tank racks at gas stations mere feet from the gas pumps. As long as they are sealed, and no valve attached, they are very safe.

Thats not a spare ! + gas stations don't have bilges to collect leaking propane.
As soon as I saw what was going on I got off the boat and had him disconnect the tank and shorepower before I got on to complete the inspection.

Members on this forum are rare exceptions to what goes on in the real world. Somewhere between 70 & 80% of the boats I survey have significant and serious issues and about 80% of those are the work of amateur electricians that think they know what they are doing.
 
Am about to install what SoWhat suggests on our Albin-25. The DuNORD is 42 yes old and never has had a 120v outside inlet for marina power. I'm apprehensive about continuing to dangle an extension cord past the cockpit canvas.
 
Thanks BoatPoker - yep, our new to us boat has original small propane tanks in a rack under the FB dash - they are original (1988) and secure, but not up to current standards. I'll be installing a proper tank locker with remote cutoff, solenoid valve ...properly drained etc, as we like to cook with gas:thumb:
 
Thanks BoatPoker - yep, our new to us boat has original small propane tanks in a rack under the FB dash - they are original (1988) and secure, but not up to current standards. I'll be installing a proper tank locker with remote cutoff, solenoid valve ...properly drained etc, as we like to cook with gas:thumb:

You may find some useful info (or not) at Safe Boat Propane Installations
 
I deal with a couple of marinas who are getting more careful about the boats they accept. All slip applicants must supply a current survey with their application. Often these marinas find the survey reports ..... shall we say, inadequate. When they receive a survey report they consider inadequate, they hire me to do safety inspections (not a full survey) prior to approval for a slip.

Some members here find my comments a little harsh but take a look at this inspection report (one of my favourites) of a vessel that applied with a survey report that recommended little more than pfd's and fire extinguishers. I see this kind of thing every week. No doubt it has jaundiced my opinions.

That is a scary boat. Most boat fires are due to electrical problems. That boat is loaded with electrical problems. Then there is the propane tank. Even storing a tank there is a major problem. I won’t even store one below decks temporarily. If you have any leakage how do you evacuate it on a diesel boat that probably doesn’t have bilge blowers since they are not required. Also most diesel boats do not have everything ignition protected like a gas boat. So if you have a propane leak how do you safely vent the propane overboard before you get a spark that ignites it? Comparing a boat to a gas station is apples and oranges.
 
That is a scary boat. Most boat fires are due to electrical problems. That boat is loaded with electrical problems. Then there is the propane tank. Even storing a tank there is a major problem. I won’t even store one below decks temporarily. If you have any leakage how do you evacuate it on a diesel boat that probably doesn’t have bilge blowers since they are not required. Also most diesel boats do not have everything ignition protected like a gas boat. So if you have a propane leak how do you safely vent the propane overboard before you get a spark that ignites it? Comparing a boat to a gas station is apples and oranges.

Did not mean to compare boat/gas station - just pointing how unsafe the racks of propane tanks look at gas stations - very easy to run into them with a vehicle:facepalm:
 
Guys,

We had the fire marshal visit our marina in NC when the issue of extension cords came up.



He said

"extension cords are only for temporary use when someone is present"

" they are not to be left unattended"

The only correct method is approved cords and inlets



Anyone can disagree but that is what the fire marshal said.



Bill



That is good advice. Constant 12amp loads are stressful to 15a systems. Even in good condx.
 
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