Need inverter recommendations

EnduranceEndurance Solar Expert Posts: 40
My first time here. I'm very happy to have found you all. I am hoping you can help me with an inverter issue.

My two-and-a half-year-old Xantrex Freedom Marine 12v 2500 watt modified sine wave inverter/charger is dead . . . again. It died once after about a year of service and Xantrex put in a new circuit board. They said I killed it with a power surge. I got it back and installed it behind a new 30a surge protector from Progressive Industries. Now it's dead again and it's out of warranty. Clearly it wasn't a power surge this time and probably wasn't a surge the first time either.

My first question is about why my inverter had such a short life. My installation is on a houseboat at Lake Powell on the Arizona/Utah border. My inverter is in a closet. I try to keep the closet doors open to provide more cooling. Still, there's only so much cooling you can give with typical daytime temps over 100 F. My primary load is a 36" residential side-by-side fridge that is also working in high ambient temperatures and therefore draws a fair amount of power. It uses between 200 and 400 AH overnight and can go through 1000 to 2000 AH during the day. Much of the daytime use comes directly from a generator, a Honda EU3000. My battery bank has 8 T-105 size AGM batteries with just under 200 AH each at 6v. The 750 AH battery bank gives up power when the generator is off and charges when the generator is running.

My guess is that the factors leading to my inverter's premature death have to do with working it fairly hard in high ambient temperatures, but I will welcome any thoughts about what else I may be doing wrong.

Unless there are major changes I can make to be kinder to inverters, I am thinking I need a different type of inverter to give a better service life. My second question is whether anyone has a recommendation on an inverter more likely to live in a hot environment. I may need to get away from a marine unit to gravitate away from weatherproofing and toward more air flow. For these reasons, I am thinking about either an Outback or a Magnum unit - most likely between 2,500 and 3,000 watts and most likely true sine wave.

I may also want to use some computer fans to bring in air from the coolest place I can get air - between the pontoons on the houseboat. But that introduces humidity that may do more harm than good.

I am hoping there are steps that will give me an inverter with years of trouble-free service. I pray that's not a pipe dream.

Comments

  • westbranchwestbranch ✭✭✭✭ Solar Expert Posts: 5,151 ✭✭✭✭
    Re: Need inverter recommendations

    A friend and I just diagnosed a 'roach' pee problem on the Circuit board of his Freedom 3000. IMHO it is a piece of c**p, came from the factory in that condition...manuf in 2011. they grudgingly did a warranty repair after he threatened to involve his lawyer.

    So.... look for another marine type inverter/charger, I believe Victron are marine grade http://www.victronenergy.com/

    I also think you are having some problems with running 8 batteries @ 12V , you probalby should consider 24 volt configuration as it would do a better job of keeping the batts balanced.

    HTH

    Others will jump in I am sure

    ps I think you hit the nail on the head, that fridge would be pushing the limits of that inverter, electronics don't like to run near max all the time...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • CariboocootCariboocoot ✭✭ Banned Posts: 17,615 ✭✭
    Re: Need inverter recommendations

    Welcome to the forum.

    I think you're spot-on about the problem: inverter running for long times in hot climes. Worse, being a MSW type the 'frige will draw even more power.
    Also agree with Westbranch that a 24 Volts system will give you some advantage.
    Outback makes inverters specifically designed for marine environment: http://www.solar-electric.com/oupomorandma.html
  • BB.BB. admin Super Moderators, Administrators Posts: 29,634 admin
    Re: Need inverter recommendations

    If you can justify it... Yes, a TSW (true sine wave inverter) will be better. MSW running motors (and many small electronic devices) can case the motors/devices to overheat (~20% more power wasted as heat, in many loads, because of the Modified Square Wave form).

    All About Inverters
    Choosing an inverter for water pumping

    It is possible that too small of diameter and/or too long of wire run for the 12 volt power cables (and too small of battery bank) may have stressed the inverter (running at "low voltage" DC input voltage causes AC inverters to draw more power. Power=Volts*Amps -- If volts is 20% low, current will be 20% higher, and waste heat in the inverter could be 1.22=1.44x higher == Power=I2*R).

    Wet and hot environments with large temperature swings don't help either.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EnduranceEndurance Solar Expert Posts: 40
    Re: Need inverter recommendations

    Thanks all for the info. The cables going from my battery bank to my inverter are ten feet long, but they're 4/0 as are the jumpers between batteries, so everything should be good there.

    As for the 12v vs 24v question, using a 24v inverter would be a no-brainer if all of my power loads were 110v. But my boat has pumps, lights, radios, a uv water purifier, a TV, a DVD player, and some fans that are all 12v. I have thought about using a 24vDC to 12vDC transformer to power my 12v loads, but that seemed to introduce complexity, cost, and heat loss that I would like to avoid if possible. I thought about tapping into part of a 24v bank to pull 12v, but that seemed like it would cause more imbalance problems than just using a 12v battery bank. Given that 12v vs 24v is my first choice, I guess some input on which voltage to use for my battery bank would be something I should learn more about. What do you think about this kind of situation where I have both 110v and 12v loads?
  • EnduranceEndurance Solar Expert Posts: 40
    Re: Need inverter recommendations

    Sorry, I should also have mentioned that a 24v battery bank would have additional benefits when I upgrade from generator power to solar power. Right now I have a single 120 watt 12v panel with a SunSaver 10 controller. My plan for the future is something more like a Midnite Solar 150 Classic controller with about 1200 watts worth of panels. If I have a 24v battery bank, my understanding is that I can get twice the panels on the same controller. That sounds appealing, but even at that I don't know if it's worth using a 24v to 12v transformer big enough to handle 50 amps at 12v. I guess that's what I hope to get more information about.
  • BB.BB. admin Super Moderators, Administrators Posts: 29,634 admin
    Re: Need inverter recommendations

    Yes, 24 volts supports 2x larger Wattage array vs 12 volts on the same rated (amperage) controller.

    By the way, there is no "DC Transformer" in the sense of AC transformer.

    DC Converters are (usually) electronic switching power supplies which can step or step down the voltage with pretty good efficiency. However, like everything electronic, if you leave them on 24x7 or power small and big loads--the "standby/conversion" losses may have to be taken into account.

    They can work well--but you need to understand your loads and the limitations of DC to DC converters.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Blackcherry04Blackcherry04 ✭✭✭ Solar Expert Posts: 2,490 ✭✭✭
    Re: Need inverter recommendations

    Endurance, welcome from a fellow house boater. Sounds like you had a visit from the gremlins. The guys here are right on with the 24 v setup if your willing to make some changes. I have 2 banks, one 4 battery bank of GC-2's @ 24 V and one 10 battery bank of GC-2's @ 12 v. I run my frig on the 24 V bank as it's the most critical.

    Inverter / Charger Type are under the most strain when charging. You can listen to the fans as soon as the charger kicks in they go to wide open. I have a A/C duct right over my inverters to keep them cool when charging. Sounds like some venting would help you.

    You never said what the symptoms are with your Inverter. I have a Inverter service center close to me and I can run down and see them. Sometimes it something real simple. There are a couple fuses on the circuit control board that have a habit of blowing from time to time. it's electronics, you just never know. The Magnum Inverters is what others have been recommending to me. Xantrex does not want field repair service any longer, so they are hard to get repaired.
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