Inverters, AC Power, etc... What would you do?

[ssullivan]

Hi Everyone,

Looking for some input on a proper (and cheap) setup for a particular situation involving inverters, AC power, etc...

I have 2 areas that need AC current. One, at the nav desk, where my computer and related equipment is. Nav desk is to starboard, next to batteries. Second, on the port side of the salon, where the TV,DVD, Stereo, Etc.. are being installed into an "entertainment center."

Currently, I have a small 600 Watt inverter running off my house batteries (small bank... only a couple hundred amp hour). This 600 Watt inverter is powering my laptop, computer network, and equipment for my WiFi setup. Wiring runs from an "accessory panel" (DC) to this small inverter, which is located in a compartment where all this electronic stuff is.

On the port side of the salon, I'm basically starting from scratch. The idea is: I would like to be able to run my entertainment center (all AC powered equipment) from the batteries.

Is it better/cheaper to get a 2nd small inverter and run some more DC lines over to the port side (given that the batts are on the starboard side, further aft), or is it best at this point to just bite the bullet and get a real inverter for the boat?

I would like to get the real inverter for the boat, but a couple things make me hesitate:

1) They are expensive
2) Installation sounds like it invoves xfer switches, etc...
3) I would still have to run an AC line over to this port side of the salon since for some reason, it doesn't already have an outet.

So... what would you do?

Small inverter again, with a DC line run, or a ship's inverter with an AC line run?

Thanks,

Option 1 more DC appliances.
Option 2, A larger inverter. I have the Xantrex 2500 wired directly to my shore power, then to my AC panel. THis accomplishes a couple of things. One, I can isolate my AC power. 2 I use the inverter to charge the inverter bank (this is seperate from the house bank), and 3, I can run any appliance that my shore power can handle, with or without shore power. This is a very simple install, and keeps the system simple and easy to maintain.
As for cost, Again, I say go outside the box. RV vendors have these inverters much cheaper than West Marine, and I have talked to the Xantrex service guy about the difference. THe unit is sealed exactly the same, but the marine unit has a more sophisticated charger, set up for multiple battery banks. No issue for my set-up. I have also found a couple of EBay stores that have these inverters in the $800-900 range.
The draw backs to the system you proposed are in the inefficiency. The small inverters are not very efficient to begin with, and the added complexity of an inverter for each location can be irritating. It will also look tacky. FWIW, I am able to run my hooka from the inverter for working on the hull, with no problem. All of my power tools also run well from the inverter.

[sv_makai]

Due to a second faliure of our herat charger invertor makai has been switched to a invertor with a seperate charge. Though we never use the charger in a marina except to equalize the batteries.

After the failure and the cost to ship the charger to st martin for repairs and return it we decided to install a Prosine 1750 invertor (biggest we could get in the Caribe) for 455 US. In the US we saw 299 price tags. We have a shore power\ invertor switch that allow us to chose the source. At anchor which is mmost of the time we are on the invertor. it works well and has a fairly good overhead so the waste amps is only about 20%.

For the laptop we had a dc-dc 12 volt to 19 volt invertor made. It has even a lower over head as it plugs directly to the battery system. Huge losses occur when using the invertor to go from 12 to 110 and 110 to 19 volts (most computer charge rates). A good invertor losses 20 percent or more from 12 to 110 and then again from 110 to 19 volts.

Also the dependence upon the invertor to charge the computer batteries is eliminated. We would have been hosed as we were without an invertor for 8 months the first time and 2 months the second.

Bil, I do not disagree with you, but... for use within the US, Xantrex has been very easy to work with for me. My unit failed after the first year. I called the dealer. THey were no help. I then called Xantrex, and they located a local service center. I dropped off the unit, and had it back 3 days later, at no charge. It has worked fine since with 24/7 usage. I do have a seperate charge that charges the house bank, and the engine bank. This seems to run fine through the inverter. Granted, the inverter is in bypass mode most of the time, but we have had a couple of power outages at the dock, and it has switched over and worked fine.

[sv_makai]

Even in the Caribe the Xantrex service was good even though a bit convoluted.

We had ours repaired once under warrenty without a problem. The second time is was not under warrenty and would have cost near 400 for shipping plus repairs. When it worked we liked it very much, but found that counting on it was worriesome.

The first failure we had another boat taking the identical unit to Trinidad for the exact same problem for repairs under warrenty. The problem actually comes from the import rules for Trini. If you are there anything can be shipped in duty free. If you want to ship it in for repairs and then back out then you pay duty. Stupid but it prevented us from using their warrenty site and having to look at st martin with more costly services/

It was cheaper to install a seperate brand new invertor than deal with repiars of a unit that had already failed twice in a year. The final disconnect was when the invertor failed and with out warning would turn it self on and start drawing 455 amps. This was the point theat it was totally discounted. Since we use solar and winds to maintain our house that lack of the charger function is not a problem and we will address it when we return to the US late next year.

I think I will still go with the sepreate systems rather than the combined as the ease and cost of replacement and repairs outside the US is an issue. But who knows I may change my mind in the future. But first I need confidence in the units.....

[Jon D]

Couple of other thoughts.

I'm running a ProSine 2.0 which is another Xantrex product. 100 amp charger 2Kw inverter.

I would suggest going the large route. Couple of reasons 1. you can run large power tools should you ever need to. 2. same goes from microwaves, hairdryers etc. My wife likes to dry her hair and the 12v takes forever and does not get very hot. With the inverter she can take a conventional dryer and be done in 5 minutes. Burns about 2 amp-hours or so. I can also run the shop vac etc with no problems. Downside is some take the shore power to the inverter and switch from there. This makes for more complicated wiring and if the inverter fails you can find yourself without 110 into the boat if you don't have a bypass switch.

[ssullivan]

Kai Nui once whispered in the wind:
Option 1 more DC appliances.
Option 2, A larger inverter. I have the Xantrex 2500 wired directly to my shore power, then to my AC panel. THis accomplishes a couple of things. One, I can isolate my AC power. 2 I use the inverter to charge the inverter bank (this is seperate from the house bank), and 3, I can run any appliance that my shore power can handle, with or without shore power. This is a very simple install, and keeps the system simple and easy to maintain.
As for cost, Again, I say go outside the box. RV vendors have these inverters much cheaper than West Marine, and I have talked to the Xantrex service guy about the difference. THe unit is sealed exactly the same, but the marine unit has a more sophisticated charger, set up for multiple battery banks. No issue for my set-up. I have also found a couple of EBay stores that have these inverters in the $800-900 range.
The draw backs to the system you proposed are in the inefficiency. The small inverters are not very efficient to begin with, and the added complexity of an inverter for each location can be irritating. It will also look tacky. FWIW, I am able to run my hooka from the inverter for working on the hull, with no problem. All of my power tools also run well from the inverter.

Hmmm... an important consideration I had neglected to take into account: Running power tools out at anchor. Guess for this reason alone, I might have to look into the larger inverter (if my 200 Ah of house battery power is sufficient to get any work done). Otherwise, I would have to fire up the genset for "tool time."

[ssullivan]

sv_makai once whispered in the wind:
Due to a second faliure of our herat charger invertor makai has been switched to a invertor with a seperate charge. Though we never use the charger in a marina except to equalize the batteries.

After the failure and the cost to ship the charger to st martin for repairs and return it we decided to install a Prosine 1750 invertor (biggest we could get in the Caribe) for 455 US. In the US we saw 299 price tags. We have a shore power\ invertor switch that allow us to chose the source. At anchor which is mmost of the time we are on the invertor. it works well and has a fairly good overhead so the waste amps is only about 20%.

For the laptop we had a dc-dc 12 volt to 19 volt invertor made. It has even a lower over head as it plugs directly to the battery system. Huge losses occur when using the invertor to go from 12 to 110 and 110 to 19 volts (most computer charge rates). A good invertor losses 20 percent or more from 12 to 110 and then again from 110 to 19 volts.

Also the dependence upon the invertor to charge the computer batteries is eliminated. We would have been hosed as we were without an invertor for 8 months the first time and 2 months the second.

Hmmm... good points. Being able to just junk a small inverter and buy a new one for $200-$300 is very attractive. No worries about a failure taking out the entire boat's ability to generate AC from DC sources. Plus, I suppose you could switch inverters around if one went out... allowing you to still use all the components.

It's not efficient, but all of a sudden (since I figured out the most efficient way to refrigerate at anchor), I have excess DC capacity even at a couple hundred Ah. These batteries will be topped off every day by a genset run, or by motoring on some occasions.

I'm not sure I'm anywhere closer to a decision. Kai Nui and Bill make good points. I suppose I have to sit back now and reason this out, taking the tools and reliability factors into account.

This is a tough one!

PS: I wanted to do the DC transformer as well for my latop, but decided to just live with the inefficiency for the time being. In a perfect world, that is the best solution. But... I have other equipment in the same area that has to run off the inverter - for instance - a router and an amplifier for my WiFi signal. So... I would still need AC there anyway. Sometimes, I wish I didn't need all this junk and could just do normal sailing. Our customers require this kind of stuff.

That is another selling point for the system I describe. With several small inverters, you may find your guests plugging in items that the inverter can not handle (i.e hair dryers) My system will handle wull current at any outlet. And, when you are underway, or at anchor, you can plug the genset into hte shorepower plug to use the charger without making any other changes. Overall, this makes the boat AC system more user friendly for the guests. No worries about switching things on and off, or waiting for the house bank to recharge before using the a/c. As for power tools, the genset will probably be a batter source for running those items. The majority of my power tools are cordless Dewalt anyway, and I just keep the batteries in a charging station. Projects that would require more than that are done at dock. I am convinced about the advantages of a bypass however, as it would suck to have the inverter fail, and not be able to switch over to the genset. Again, especially with paying guests on board. I do have a battery switch on the inverter, so I can seperate the batteries from the inverter in case of the type of failure that Makai had. As for the computer, the DC to DC transformer is absolutely the way to go. I also have a 12 volt printer, the Cannon BJC85. I will also say that the Prosine inverters are a good quality unit, and worth the extra money. That said, Prosine, Xantrex, and Trace are all the same company. They used to be seperate, and for residential use, the Trace was by far the best, but Xantrex bought all of them out. I do not think the quality as suffered. Another aside, I would avoid the Triplite inverters, as tey are much less efficient, and lower quality.

[Alan Wheeler]

Just to add some more thought. Some of it overlaps others suggestions.
Firstly, inverters use hugew amounts of DC power. So you need good heavey cables from batteries to the inverter. The longer the run, the bigger the cable. The bigger the inverter, the bigger the cable. I have a 3KW inverter with peak ability of 6KW. I have to use 75mmsq cable to make the 4m run from battery bank to inverter. Right, so to get to my point, this means it's best to keep your inverter as close to the battery supply as possible and run the AC cable the distance across the otherside of the boat.
Next, true Sine wave is best for running your entertainment centre. These are expensive. So having two smaller ones and then one of those being able to used as a backup as well, has some merits. Then use a big modified sinewave unit to run tools. The modified sinewave units are cheap. I paid NZ$300 for a made in Taiwan type unit. It runs tools and freezers and the Microwave.

NOTE!!! Running tools maybe nice, especially if it is just a quick job. But it chews battery power real fast. So if you have a bigger job, you are going to have to start the Geny up anyway. Whether it be to run the tools or charge the batteries.

My system is set up such, that I have a selector switch on my AC/DC panel. I can switch from shore to Gen to Invert with the turn of the switch. All AC from any source is then directed into the ships AC wiring. The selector switch is such, that Phase, Nuetral and Earth are isolated from each three seperate power supply sources. Otherwise, should two differing source Phases ever come into contact, especially if it's shore power, trust me, the national grid will win the battle. If Earth and Nuetral ever get switched back to shore sources, RCD's, ELD's, GID's or what the heck every different country calls them, will trip out.

THe Xantrex are modified sine. In fact, the technology has gotten to the point that only the absolute bottom of the line inverters are not modified sine. I agree with the point about using the genset for power tools, but it is nice to know that no matter the situation, power is available.

[ssullivan]

Kai Nui once whispered in the wind:
That said, Prosine, Xantrex, and Trace are all the same company. They used to be seperate, and for residential use, the Trace was by far the best, but Xantrex bought all of them out. I do not think the quality as suffered. Another aside, I would avoid the Triplite inverters, as tey are much less efficient, and lower quality.

Add Portawattz to that list. My current inverter is a 600 Watt Portawattz which was alos either bought by Xantrex, or was what Xantrex was called a while back when I bought the thing.

[ssullivan]

Wheels,

The cable runs were high up on my list. I definitely wanted to avoid heavy, expensive DC runs all the way across the boat to the entertainment center. No matter what choice, the best way is certainly to locate the inverter close to the batts and then run the AC over, resulting in lower amps. This is definitely how it will be done.

Still thinking hard about this, since Kau Nui has so many good reasons for a large inverter (and the neatness it entails). At the same time, I might be leaning toward the smaller, cheap ones for economics and redundancy.

Still on the fence.

[Alan Wheeler]

Just remember some devices, especially motors, require at least three times thier operating current to start them.
We started with a 2KW inverter, but it wouldn't start the Vacum cleaner. The 3KW one does. I also imagine the quality of inverter may differ as to what it will start and drive.

[Jon D]

As was pointed out Xantrex owns lots of brand names however not all are created equal. For example my Prosine is a full sine wave inverter with a high efficient charger 100 amps @ 12v for 15amps @ 110. The Heart Freedom equivalent at the time was modified sine wave and took 25 amps to put out 100 amps @ 12v. Not sure what the current specs are.