Inverter

[blair]

Hello all,
I just acquired a 3000 watt modified sine wave inverter to complement the 6500 watt Onan and have been reading various opinions on battery banks and installation. Now my brain hurts.
I'd like to ask anyone here,especially those with a Tricabin, how and where they installed it on their boat, what they use for a battery bank (in addition to starting batteries) and how they go about charging the new battery bank (IE: Can I use the engine alternators or do I need a secondary set of chargers?) There seems to be a ton of information about these inverters but I'd just like to hear what works for others here.
Thanks,
Blair

[prowlersfish]

Blar , I am not the best person to answer But perhaps I can help some . What do you plan on power with the inverter ? And for how long ? The Alternator on your engine would not keep up with the inverter under high/heavy load . With a good battery system you could run some higher loads and recharge the battery's over time. But if your going to run constant high loads like a A/C then its Time to use the Gen set.

There are others that use a system like you want to hopefully the will chime in . In the mien time , tell us exactly what you want to run with it and for how long. Better info = better answers

[Big D]

So I assume we don't have to tell you that this could be a somewhat complicated topic! First I will say that I personally would not run anything or combination of things at once on an inverter that would require drawing that much output (3000W). I would be running the generator for that, it's my personal preference given the battery requirements for lengthy loads at that wattage. You should start by reading the installation manual carefully. There you should find the requirements for battery bank capacity to run that amount of amperage however your own personal habbits/needs will play a large roll here. It will also explain proper cable sizing, unit placement, duty cycles, etc. If it has good documentation, it will also recommend the appliances that perhaps should not be run on this inverter given that it is a modified sine wave design. Now that you have a 3000W unit, you need to wire it as such. In otherwords, don't think that you can wire it based on the thought that you'll never run more than 1500W. That can be dangerous. If this is to be incorporated into the ship's electrical system, pay very close attention to how it should be wired and follow that closely. Having said that, if it is not designed for marine use, it may not display the proper way to wire it in a marine application. This can pose a safety issue. If you are hooking it up to ship's systems, use a rotary source switch to select "Ship, Shore, Inverter, Generator" this will prevent feeding from another source at the same time as the inverter which is sure to kill it. There are also auto switching units where other sources such as shore and generator are passed through when hooked up and upon disconnecting switch the inverter on automatically. I don't like this feature. Careful how you hook these up. If it is not marine rated, it probably isn't ignition proof either so you can't place it in the engine compartment. If that's the case, the install can get pretty pricey given that when you get into these wattages, cabling is doubled up to handle the load even on short cable runs in the engine compartment let alone having to place it elsewhere. The price of the cable alone for this reason warrants the purchase price of a marine rated unit so you don't spend hundreds on cable. These things can draw huge amounts of power so don't skimp on the wire and hardware you use. At high loads, these will have no problem melting poor quality hardware. Lastly, one should always put a notice by the electrical panel advising that an inverter has been installed and that measures need to be considered when servicing the A/C system/wiring even if shore power is disconnected given that the system may be charged by the inverter.

[blair]

Hello,
Thanks for all the input. I should have added that we are only going to use it for short term loads...coffee maker, toaster, 1000 watt microwave, laptops (if they'll run on a modified sine wave - I know some don't) etc...No long term loads planned,such as a fridge or disco ball I have done a ballpark estimate of amps/watts and time so I figure 3000 watts peak is probably about 1/3 more than what we plan to use it for. I'd just like it to be handy for short term loads when starting the genny may not be the best option.
This unit is not marine rated, so I'm getting into 0/0 gauge cables, doubled into two positive and two negative inputs on the inverter, with enough to ensure it's not mounted in the engine bay.I'm more concerned with keeping the run of cable short, yet having the inverter in a handy location. I'm not planning on tying it all into the house system, more of an adjunct to it at this time, but a rotary switch sounds like a great idea anyway. All the "smart" work will be done by a licensed electrician...I'm pretty good at putting fires out, but I don't really like bringing my work home to the boat...my wife hates that
More often we will be on shore power and I have a reliable multi-stage dual battery charger that takes care of the deep cycle starting batteries.
I'm just curious how others are mounting there inverters, the size of their battery banks and how they recharge the deep cycle inverter bank. I also realize that everyone has different needs and useage so I'm not expecting the "perfect" answer...just some ideas I might incorporate into my plan.
Thanks

[alexander38]

here's how I use mine. I too ran 0/0 cable to it 5k watts non-IP and put it in my lower helm. Her Galley is just forward of my lower helm. I then ran wire from it to an outlet installed in Her Galley. I put male plugs on the wire from the Inverter to outlet. The Inverter I bought has a remote on/off if yours does it opens up alot of places you can hide it. I run mine off 2 4d's which are also my Start batteries, I don't use it alot most underway to run Coffee pot and Micro-wave 1k watts and the G. Foreman jr.


And for those who are out there....I used tinned wire....

[ready123]

No mention of a large Amp fuse on the positive feed from the battery

I must agree with others that an inverter like that requires a V large battery bank. I also go the route of a generator for high loads... it just makes sense to me to not go the way of inverting with the associated conversion losses for high loads.
I do have a 1,000 W inverter for small use and run one thing at a time... coffee maker etc: Heavy DC cable and fuse as part of install.
I got my information from a mobile power services guy who installs batteries and inverters in trucks for supporting a mobile office.
I'm not sure the 'usage' theory of over sizing in fact benefits an inversion circuit.

I use a three bank smart charger..... 1 leg port engine, one leg starboard engine, one leg house bank.... the Onan genny charges it's own start battery so no need to connect to another charger.
Oh and my starting batteries are starting batteries and the deep cycle is for the house bank. I don't believe there is in fact such a thing as a deep cycle starting battery........ but that may well be a whole other thing.
Put simply starting batteries need to handle high loads for short periods and deep cycle handle normal loads for long periods....... the design for each of those conditions is quite different

On my diesel boat I don't have an inverter..... I just run the genny when I need to, it is in a sound enclosure and quiet.

[alexander38]

Re: Inverter

Unread postby ready123 » Thu Feb 14, 2013 9:14 pm
No mention of a large Amp fuse on the positive feed from the battery




Good point Ready, Yes install one on each hot lead.