Need your help to decide...

pjudepjude Registered Users Posts: 9
Hi,

I'm been asked by a friend to help him decided which inverter to purchase for a small cybercafe/game room that he has. Currently the cybercafe has 10 computers based on Atom technologies. Which means they do not consume lots of energy. He has about 6 video games including 6 19inch flat screen TV. He wants to purchase the Xantrex Freedom SW3024 inverter (thinking that if something happen with the inverter he would easily find someone (locally) with knowledge of Xantrex to work on the inverter for him). He is not sure if that is a good Inverter to purchase for Haiti (taking into consideration dusts and the hot weather). He would like the Inverter to switch to charging mode when Generator/Grid is available.

I remember a while back in this forum, members have recommended buying Outback inverters. I have advised him to look into buying an outback inverter instead. Reading somewhere on the internet, the SW3024 inverter needs lots of ventilation , otherwise it would overheat easily. I'm not sure if that is true or not. By recommending Outback inverters I'm not sure which model comparable to the Xantrex to purchase. Reading on Outback inverter I read some are vented and some are sealed.

May I request your assistance:
Should he purchase a Xantrex Inverter?
Would you recommend him buying the Xantrex Freedom SW3024

Should he purchase an Outback Inverter?
Which one should he consider a sealed or vented model?
Is the Outback VFX3524 or Outback FX2524T a good choice?

Thanks,
Jude

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Need your help to decide...

    The first thing he should purchase is a Kill-A-Watt meter. You need hard numbers for both the total maximum load (which will determine inverter size) and the total daily Watt hours (which will determine battery bank size).

    That said, I would prefer the Outback over the Xantrex because Outback makes sealed units (also vented ones, make sure you get the right one) and they have a well-deserved reputation for longevity in harsh conditions. The "VFX" models are vented, the "FX" models are sealed.

    Not sure what the standard power is in Haiti, but you will need to know that too. Probably NA 120/240 split phase 60 Hz, but it might be 220 single phase 50 Hz as used in Europe. Outback makes inverters for both.
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Need your help to decide...

    Sorry, but that number of video games, computers and flat screens is not " a small load". Like we always say,, do a real load calc, size and duration then figure out the solution for the problem.. Don't buy hardware until you define the problem!

    Ready, fire aim!

    Tony
  • BB.BB. Super Moderators, Administrators Posts: 32,607 admin
    Re: Need your help to decide...

    I am a little lost--Is this making a large UPS (uninterruptible power supply) powered from the Grid or a hybrid solar Grid Tied / Off Grid system?

    If this is to be a solar powered (to some degree) system--If he is in the Boston area, then the hours of "noontime" equivalent sun (fixed array) is:
    Month    Solar Radiation
    (kWh/m 2/day)
    1      3.36     
    2      4.36     
    3      4.79     
    4      4.92     
    5      5.33     
    6      5.41     
    7      5.60     
    8      5.64     
    9      5.13     
    10      4.65     
    11      3.14     
    12      2.98     
    Year      4.61      
    

    A pure grid tied system (no batteries) has a derating factor of ~0.77 and a pure off grid system (batteries+inverters+panels) is around 0.52 efficient...

    So, a 5kW array assuming a minimum (~20 year average) of 4.36 hours of sun per day for 9 months of the year (February) would be:
    • 5kW array * 0.77 grid tied * 4.36 hours of sun minimum = 16.8 kWH per day Grid Tied (typical)
    • 5kW array * 0.52 off grid * 4.36 hours of sun minimum = 11.3 kWH per day Off Grid (typical)
    For an off grid system, we would assume the balance during winter/streaks of bad weather, would be carried by a genset.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Need your help to decide...

    From what I read in the OP, the system will be located in Haiti and is needed because utility power is undependable there.

    But the actual numbers for the loads are necessary before any further design can be done. Otherwise it's just guessing.
  • BB.BB. Super Moderators, Administrators Posts: 32,607 admin
    Re: Need your help to decide...

    Oops... you are correct. I missed it the second or third set of posts.

    -Bill :blush:
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • pjudepjude Registered Users Posts: 9
    Re: Need your help to decide...

    Guys I truly appreciate your assistance with this request. My friend estimate the load to be a little bit over 2500 watts. Please it is unlikely all the computers will be operating at the same time during the day. In the evening it is a different story, however, the generator will be on to compensate for the extra load. 4 out of the 6 video games are the Wii. The Wii does not consume lots of power.

    The standard power is in Haiti is pretty like the US (120/240).

    Would you please educate me the difference between the outback vented and sealed inverter? In my situation should I choose the vented or the sealed?

    Thanks,
    --Pascal
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Need your help to decide...

    If the environment is dirty, buggy, or otherwise likely to cause problems go with the sealed unit.
    Since there is every reason to believe that at some time the loads may total 2500 or a bit more, the FX3048 would be preferable (in my opinion - others may disagree). It will draw less than 100 Amps at full power. It does use quite a bit on its own (23 Watts I think) but has a 93% efficiency rating.

    You still need to know how many total Watt hours will be used to size the battery bank properly. Otherwise the generator will need to be run more - or the power goes off (we'll consider the grid availability to be unreliable). With a 48 Volt system, eight "golf cart" type batteries should be able to supply up to 5 kW hours per day.

    Panel power could be a problem as the climate is hot there, which will reduce output. The array will be around 1400 Watts, maybe less. You also need to gather data about wiring distances so that the right sizes can be obtain to keep losses to a minimum.

    And I'll warn you now this will not be cheap.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,987 ✭✭✭
    Re: Need your help to decide...

    I personally found the seal FX units to be very unreliable, the power rating is at 25C even though the seal units get very hot ( cases getting over 70C ), even when well below the rated power. They vented units are identical to the sealed electrically. I went through 3 board sets with very moderate usage in 5 years. They wouldn't even be in the running if I was designing for the installation, the design is now close to 13 years old .. and Yes I know Outback isn't that old ...
  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Need your help to decide...

    Jude,

    The things to consider are:

    -- What will the loads actually be -- even low power computers add up when they are running

    -- Which inverters can you get in Haiti? Inverters tend to be pretty heavy for checked luggage, so you are likely to want to purchase an inverter in Port au Prince.

    -- A 48 volt string of 8 T105 batteries is easier to wire correctly than a 24 volt set made up of two strings of 4 T105 batteries.

    -- How larger a generator can you get to charge when the power is out

    Figuring all of this out takes some effort, but once you get the detailed answers you can see what will work for you.

    Keith
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