Inverter Install Question

Sep 20, 2015
123
Navigator 4200 Classic New Bern, NC
Another option is to just install one or two new outlets wired directly to the inverter. Those can never be powered by shore power so you don't need the complicated switching mechanisms.

But if the purpose is to power fans, why not just add 12 volt fans. We have 6 of them on our 31 foot boat living in the Caribbean. They run almost nonstop. Far more efficient than running them through an inverter.
I really like the separate outlet idea. I will give that some thought. However, I was kinda trying to avoid running new wires around the boat if it could be avoided. She is a reasonably new (2000 model) powerboat and running wires ain't the easiest thing to do. That said, that is why I was hesitant to just add 12V fans. I'd need to add a new 12V circuit in the bedroom (unless I can pull off the lighting system somehow. Come to think of it... maybe THAT is my fan solution. Hmmmm...
 

MitchM

.
Jan 20, 2005
1,031
Nauticat 321 pilothouse 32 Erie PA
fans: we installed 2 programmable Caframos. they draw about .2 a and can be programmed to turn themselves off in 2 4 or 6 hours and to run at 3 different speeds. TV: the 12v TVs sold for long distance truckers are adequate, but picture quality is not as good as the 120V powered models..
when selecting an inverter be sure to ask what size house battery bank you need. our 1000W master volt sine wave inverter will run our 1000W microwave and galley electrics, but certainly not the 120v air conditioner. we need a 400 Ah house bank for the inverter to work properly and not burn out the house bank and leave us without nav lights ...
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
That said, that is why I was hesitant to just add 12V fans. I'd need to add a new 12V circuit in the bedroom (unless I can pull off the lighting system somehow. Come to think of it... maybe THAT is my fan solution. Hmmmm...
Open up the light fixture and see what size the wires are supplying the lights. In the case of my boat, Catalina used large 10 AWG wires. So switching the lights to LED and adding fans to the circuit was acceptable for the wire size.
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
If you plan on using cheap 12v fans from Wal&$@ or a truckers' store, try one out first with your TV. I had to replace mine with marine Carfamos because the cheap ones scrambled my tv signal.

As for the inverter discussion, I wired a 3 wire cord of sufficient size to my panel's a/c input that I can plug into the inverter to energize all the outlets that would normally be live with shore power connected. Of course, I don't use it when I'm plugged into the dock!
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
I would wire the inverter to the whole 120 volt system and be done with and easier
to do it that way for sure and than any outlet is ready for what ever you want to run any place.
I have 2000 watt inverter/charge with auto switching and with out doing a lot of wiring
I do have those small fans and they use very little amps.I do have Gen and solar and 4-6 volt GC and you be surprised how fast the coffee maker and microwave uses up
battery power.
I like not having to fire up the Gen and like the less noise but do use it to run AC and charge the batteries up when the sun goes down.
Nick
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
I wired a 3 wire cord of sufficient size to my panel's a/c input that I can plug into the inverter to energize all the outlets that would normally be live with shore power connected. Of course, I don't use it when I'm plugged into the dock!
This is dangerous, unsafe and against any and all standards shore based or marine based. Standards exist because humans forget..

Here's one from just a few days ago..

"I did burn up the first inverter after 55 weeks at anchor. I came into a dock and the first thing I did was plug in -- without unplugging the inverter. Smoke. Toasted that thing."


Human error is quite often what leads us to the reason we have safety standards.

What you've done is back feed your AC system negating any sort of proper source isolation or transfer switch. On land this is illegal. Line workers have died due to homeowners back-feeding generators in the exact manner you do with an inverter. It could also kill someone working on a dock pedestal when they assume the dock power is switched off. Out on the water you can seemingly do what you wish but eventually you plug back in. No marine safety standard allows for what you've done because it creates a safety issue and can create dangerous situations even up to the point of potentially resulting in a death..

If you want to wire a non-marine stand alone inverter, that is not built to marine UL458 standards (supplement SA), the best option is to wire it to its own dedicated outlets, clearly marked "INVERTER ONLY". While this means installing a few new outlets it is often far less expensive than a UL458 + Supplement SA marine inverter.

It is important to keep these outlets 100% isolated from the rest of the vessels AC systems. This is still not the best practice, to install a non-marine tested inverter, but it prevents back-feeding the system and neutral/Earth bonding issues.

The best option is to install a proper UL458 + Supplement SA inverter with its own transfer switch or a manual isolation/transfer switch.

A marine inverter installation should always be installed with its own internal transfer switch or an external transfer switch that ensures the vessels neutral/white and Earth/green are bonded on the vessel only when the inverter is actually operational. Neutral/White and Earth/Green are then isolated, on-board the vessel, the split-second that transfer switch breaks. A proper installation also prevents two sources which can be dangerous and potentially lethal.

When buying an inverter it is important that it meets UL458 + Supplement SA - Marine Power Converters/Inverters.

Many inverters are sold that meet UL458 (this should be a bare minimum) but most have never been tested to the marine supplement/portion of UL458...

While one side is only 12V the other is 120V and can be DEADLY...

Please install inverters SAFELY!!!
 
Sep 20, 2015
123
Navigator 4200 Classic New Bern, NC
So after all this, it seems to me that:

1) Connecting my entire 120V system to an inverter will be the easiest way for a full install, however, I would need a transfer switch. Since inverter-only units are rare birds, it looks like Victron doesn't have an automatic xfer switch option. They reco that if you want to auto switch to get one of their inverter/chargers. But I don't want another charger. Therefore, I would then need a $400 Blue Sea 9077 rotary switch to do it manually. No thinks... Not yet anyway.

2) I believe now that just getting a few 12V fans and running a few new wires around the boat... then making a 12V switch-over system for the TV/Roku is, indeed, the better idea. I will just have to suck it up and get over it :)

3) I will probably still buy a small inverter, but I will just use the outlets it has onboard itself and drag out an extension cord should the need arise.

Thanks for the input y'all. I will continue to give it some thought.
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
I have good marine 12 volt fans and they draw very little power and also lower noise
and have them mounted near a light and run the wires to the light.
The cheap walmart are very noisey and draw higher power too and have tried them but got rid of them,I got a fan last year with 4 suction feet and varied speed control and a very long plug wire and use it on my boat and RV,got on sale from ??????.
Nick
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
This is dangerous, unsafe and against any and all standards shore based or marine based. Standards exist because humans forget..

Here's one from just a few days ago..

"I did burn up the first inverter after 55 weeks at anchor. I came into a dock and the first thing I did was plug in -- without unplugging the inverter. Smoke. Toasted that thing."


Human error is quite often what leads us to the reason we have safety standards.

What you've done is back feed your AC system negating any sort of proper source isolation or transfer switch. On land this is illegal. Line workers have died due to homeowners back-feeding generators in the exact manner you do with an inverter. It could also kill someone working on a dock pedestal when they assume the dock power is switched off. Out on the water you can seemingly do what you wish but eventually you plug back in. No marine safety standard allows for what you've done because it creates a safety issue and can create dangerous situations even up to the point of potentially resulting in a death..

If you want to wire a non-marine stand alone inverter, that is not built to marine UL458 standards (supplement SA), the best option is to wire it to its own dedicated outlets, clearly marked "INVERTER ONLY". While this means installing a few new outlets it is often far less expensive than a UL458 + Supplement SA marine inverter.

It is important to keep these outlets 100% isolated from the rest of the vessels AC systems. This is still not the best practice, to install a non-marine tested inverter, but it prevents back-feeding the system and neutral/Earth bonding issues.

The best option is to install a proper UL458 + Supplement SA inverter with its own transfer switch or a manual isolation/transfer switch.

A marine inverter installation should always be installed with its own internal transfer switch or an external transfer switch that ensures the vessels neutral/white and Earth/green are bonded on the vessel only when the inverter is actually operational. Neutral/White and Earth/Green are then isolated, on-board the vessel, the split-second that transfer switch breaks. A proper installation also prevents two sources which can be dangerous and potentially lethal.

When buying an inverter it is important that it meets UL458 + Supplement SA - Marine Power Converters/Inverters.

Many inverters are sold that meet UL458 (this should be a bare minimum) but most have never been tested to the marine supplement/portion of UL458...

While one side is only 12V the other is 120V and can be DEADLY...

Please install inverters SAFELY!!!
Message received and understood! I will disconnect that cord from the panel next time I'm at the boat. Thank you for the possibly life-saving warning!!
 
Jun 1, 2009
1,838
Hunter 49 toronto
Hello again everyone!

Ok, so... After my full DC system upgrade (and y'all were a huge help... thanks), we have taken the boat out to anchor a few times and realized we could probably use a small inverter to power a couple of fans in the bedroom while we sleep and the TV/Roku. Maybe give us a few other conveniences too like coffee in the morning. Nothing major like a microwave though. For that, we will fire up the genny.

I am thinking of getting a Victron Phoenix 800-1000 watts and even that might be a little larger than I need. My panel has two breakers that I assume are 20A that power all the 120V outlets throughout the boat (there are 10 outlets total). My question is: How do I energize just those two breakers with an inverter-only unit? Will there need to be a sub panel of some kind with wires to the current breakers? Or this less appealing way... Do I need to energize the entire 120V side of the bar and turn off the breakers/systems I don't want?

Below is a picture of my panel for no particular reason. :) The outlet breakers are at the top of the far left column.

View attachment 128652

Thanks y'all!
Respectfully, I think you're looking to re-invent a wheel that doesn't need to be re-invented.
What you need is a combined charger / inverter, and I recommend magnum.
Yes, it means replacing your existing charger., but that's life.
It's one box, wires in clean , safe & you're done. Why mess around????
 
Sep 20, 2015
123
Navigator 4200 Classic New Bern, NC
Respectfully, I think you're looking to re-invent a wheel that doesn't need to be re-invented.
What you need is a combined charger / inverter, and I recommend magnum.
Yes, it means replacing your existing charger., but that's life.
It's one box, wires in clean , safe & you're done. Why mess around????
I don't disagree. That is why I backed off of most of my idea.

Replacing the charger isn't out of the question in the future, but I like the Sterling charger and it is less than a year old. I waste enough money with this lifestyle choice, that I don't want to waste it by backtracking my own work :)