Inverter Recommendation

Very interesting forum and alot of knowledge here. I need a some help on finding the correct Inverter/charger for grid tie backup. I will have 4 Surrette S-530, 6 volt 400 Ah batteries. Looking for 1500 watts and 24 volts. I was using a Tripp lite
1012...1000 watts..12 volts but it is time to replace that system with a real one:)
Currently I want the batteries recharged by Grid power for now...solar may be added within a year.

If more information is needed, please post questions and i will respond as quick as possible. Thank you.

Mike

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Inverter Recommendation

    Mike,

    When you go with solar--are you looking to Grid Tied to the utility mains, or are you going to keep this system separate (run a few small loads/or just keep for backup power after storms)?

    Do you want automatic generator starting? Or just use a small manual start unit?

    At this point, I would look at the Xantrex Prosine 3kW / 24 volt inverter/charger. It is larger than you want, but includes True Sine Wave output, AC Transfer switch, a Power Factor Corrected battery charger, and remote battery temperature sensor. They have a 2kW version also, but it is only available in 12 VDC input.

    Unfortunately, they appear to be difficult to get at this time--You will have to call NAWS directly for availability.

    I like this as a "small" inverter/charger as it has several items that are missing from many other brands... Power Factor Corrected battery charger works very nicely with generators--reduces the amount of current (Volt*Amps, VA, VAR) that the charger takes when charging. Also has a battery temperature sensor which makes for a bit faster and more reliable charging--especially if the battery bank experiences a wide range of temperatures.

    The Xantrex XW hybrid inverter/charger like would be great (above, plus 120/240 VAC split phase power), Grid Tied capable (sell the solar power back to the utility--much more efficient at getting a return on your solar array--if supported by your local utility--and then eligible for various rebates). Generator control option, etc... However, I would bet that this would be 2-4x as much as you really wanted to pay.

    Regarding a pure backup/UPS like function (with solar panels and/or shifting loads with Time of Use billing plans)... Very roughly, you batteries will last 1/2 as long when cycled daily vs just sitting in standby/float applications (emergency backup power). The Grid Tied / Hybrid XW system allows you to still use the solar panel array power without cycling your batteries (they remain at float and the inverter feeds energy to your house/utility mains when the sun is up).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Inverter Recommendation

    Thanks for the reply Bill: I do not need automatic generator starting and am going to use it only for backup during power loss. I will do manual Generator if needed but want the inverter to recharge the battery bank when Utility power is restored.
    Not selling back to the grid...just need power when utility fails which is common where I live.

    When I go Solar, it will be just for the recharge of the battery bank as I run a couple
    computers 12 hours a day. They pull 500 watts for the two plus another 160 for my TV. Checked all with Kill a watt..cool piece.

    Just trying to prepare for the future...which looks a little scary at present.

    Thanks a lot.
  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Inverter Recommendation

    Sounds like you have a good handle on the problem.

    Do you need a transfer switch (UPS function)?

    Also, you could look at making the system from piece parts (inverter + charger + transfer switch)...

    I agree with using a small system. For emergency power, using a backup generator that is too large can just suck fuel down like no-tomorrow.

    Personally, I picked a Honda eu2000i because it is still pretty fuel efficient down to 400 watts or less (~15 hours on 1.1 gallon tank of gas). Also, it is quiet enough to use in a residential neighborhood.

    Get a typical 5kW or larger unit, and you can be running a 1/2 gallon per hour (no matter how small the loads) and need 5-10 gallons of fuel per day to ride out the outage.

    So--I would look at your power needs, and pick a genset size + fuel that makes sense for your situation (gasoline, propane, natural gas, diesel, etc.).

    Then you can size the battery bank / inverter / charger to efficiently load your genset---Many times, a hybrid type system works well. A larger diesel generator + good sized battery charger and bank allows you to properly load the generator during charging and then you run for awhile with the generator off from your battery bank.

    For me, I am both cheap and limited in the amount of fuel I can store + how much noise I can make (quiet suburban neighborhood).

    I have natural gas--but plan on my "long power outage" to be the result of a large earthquake--which could knock out the gas--so I need some sort of alternative fuel anyway.

    Diesel, and "prime mover" rated gensets are usually much larger than my average power needs (fridge, freezer, few lights, radio, laptop, etc.)... So, I am kind of stuck with a light portable genset (like the Honda "eux000i" family. Plus I am not sure how well a the smell of diesel drifting among the houses would fly.

    For a step up in standby power would be an RV generator pack (many are available used from wrecked RV's). I have a friend that mounted a small Onan natural gas fed unit for his emergency power needs.

    If you have larger loads (A/C, well pumping)--perhaps two gensets, one small, one large. The larger can be a cheaper unit that only runs when you have the heavy loads.

    Because, I my planning, fuel storage/consumption is critical--I look at efficiently loading the genset (typically 50% rated power, the "eu" down to 25%) for optimum fuel usage. And I try to avoid power conversions... For example, to charge your battery bank from a genset:
    • 0.80 charger eff * 0.80 batt eff * 0.85 inverter eff = 0.54 overall eff...
    So, I could waste almost 50% of my fuel usage just to charge now and use power later...

    If I was looking to use a small genset (like the 1,600 watt Honda), I think that the 3kW prosine is a bit large... And I would look at picking some smaller piece parts to make up the standby system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Inverter Recommendation
    When I go Solar, it will be just for the recharge of the battery bank as I run a couple
    computers 12 hours a day. They pull 500 watts for the two plus another 160 for my TV. Checked all with Kill a watt..cool piece.

    If those computers are not doing a lot of processing (number crunching or whatever) their CPU's are idle a lot of the time, and upgrading to more energy efficient motherboards/CPU or laptops might be an option to consider, if you are into building computers. http://www.tomshardware.com/forum/233360-28-need-build-power-computer
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: Inverter Recommendation

    Thanks Bill and Mike...Computers are crunching most of the time. I do use a laptop while the others are working. My old tripp Lite inverter/charger switches automatically when Utility goes down and since you asked about a switch..that confuses me as I thought most of them did also. What I need now is an inverter/charger with auto switch from Utility to batteries and then back to Utility when power restored. I hope I am not confusing you..not trying to do that.
    I am really setting up for future problems with Grid (don't trust what might be heading our way) and will most likely get the Honda (thanks for the recommendation) for charging and fuel savings if problem arises. I also considered a Coleman 12K Natural Gas for the whole house, but like you said...we aren't assured of a steady supply of it if real problems arise. Just trying to take care of myself and my wife. I did learn a lot reading the Ham radio thread..that is on my list of things I have to do. Preparing for our uncertain future.
  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Inverter Recommendation

    The switch over is never 100% clean between line and inverter power... With "real" UPS's--I would see, very roughly, about 1 out of 10 fail overs that would cause the computer to reboot (my guess is that real switch overs are never clean-and they confuse the UPS power fail circuit--allowing the computer to run out of stored energy (a few cycles of power)--causing a reboot. I could never reproduce these switch over failures with standard bench gear.

    If you needed really stable power, you could go the continuous conversion route... Basically, Line - charger - battery - inverter - computer... No matter what happens with the AC line, the computer is "protected".

    But, unless you have critical computing (and no backups)--a fail-over switching UPS is probably more cost effective (and more energy efficient).

    Why I always liked laptops--they have the battery/ups function built right in--plus they are usually optimized for low power consumption.

    I have not worked with Solar RE gear--so I don't know how "glitch-less" a power failure transfer would be--but I would guess is it probably less clean than a purpose built UPS would be. You might still need a small UPS to protect the computers (might be more efficient too--just enough UPS for the couple loads--instead of UPS protection for a whole home). You could even do a version of a continuous converter with just a dedicated small TSW inverter for the couple computers and a larger fail over switching UPS for the rest of the home--All tied to the same battery bank.

    If you "build your own" out of components--you can optimize for your needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Inverter Recommendation

    Not to pick nits,

    But if we have the "uncertain future" you are worried about, wouldn't it be reasonable to assume that if the grid became unreliable then other fuel sources (Propane/diesel/natural gas might also become unreliable.

    For my two cents worth, if you're planning on a doomsday scenario that might lead to one set of solutions, if is just that your personal connection to the grid is funky you might make other choices.

    I don't wish to turn this into a great debate on the politics but I think you should be clear as to what it is you are trying to achieve. A grid back up system for a short term, occasional outage might present one solution. (cheap generator for example). Back up for common but still short term outages, might present another, (good generator or generator backed battery for example). Common, long term outages (from natural disasters like hurricanes or ice storms might yield yet another solution.

    Finally, if you are convinced that the grid is going to go down in a big, long term way, due to all manner of reasons we don't need to discuss then it seems that you might be looking for what might ultimately become an total off grid, or certainly largely stand aloneable (??) system.


    All four scenarios have cost consequences that may or may not make sense. For example, IMHO, an multiple $1000 battery based system for occasional outage might well be very much more expensive than a cheap generator.

    One other note. I generally shy away from any Coleman product that has electricity connected to it,, either gennies or appliances or tools. I have found them to be, as a rule substandard. For the nearly the same money you can often find much better quality units, perhaps used, but with much more functional life net/net.

    Tony
  • bobdogbobdog Solar Expert Posts: 192 ✭✭
    Re: Inverter Recommendation

    Well, since it was brought up let's not beat around the old bush. My guess is that a grid failure due to increased solar "activity" that is already underway and may max out anywhere from this year to 2012 is what might be being surmised here. I have no way of knowing if that will occur. Not my issue.

    What is my issue, is wondering if said solar "activity" will have any effect on an off grid system (panels, batteries, inverters, any electronics)? I have such a system and would like to know if it will fail, too if the grid is failure prone? If so, then isn't it a futile effort to plan for the possible grid failure with a back up solar/generator/battery system?

    Just curious....
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Inverter Recommendation

    IMHO, it is tinfoil hat non sense, but I will leave it to those with more knowledge of EE, solar flairs, EMR, to comment etc.

    That said, I wouldn't think a battery based or generator based system would be significantly effected.
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Inverter Recommendation

    "Solar activity" needs miles of wires to act as antenna, so a off-grid project should be safe. Also, the closer to the poles (Auroras) you are, the more likelyhood is for zap!
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Inverter Recommendation

    From my post in the Ham Radio thread:

    This guy wrote something that I pretty much agree with (with my limited education):
    To answer the specific question of the OP, it depends upon the application. Military electronic hardware, save for acceptable commercial-off-the-shelf (COTS) components, area built to specific interface standards like MIL-STD-464 (Electromagnetic Effects Requirements for Systems), MIL-STD-461 (Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment), and MIL-STD-2169 (Classified) (High Altitude Electromagnetic Pulse Environment). The latter is probably most pertinent to the question, and for obvious reasons unavailable to the public at large. However, the ugly truth about high altitude EMP is that no amount of shielding, save being buried deep under hundreds of feet of rock or dirt, is really adequate to protect sensitive microelectronics. By their nature, the electronics are delicate and sensitive to small levels of excess voltage, and it is nearly impossible to make a practicable sensor, communication system, or avionics control that has to interface with the outside world and yet is adequately isolated against large pulses.

    High altitude EMP (HEMP) devices produce three distinct regimes of pulse, referred to as E1, E2, and E3. Microelectronics are most sensitive to E1, which is due to interaction of x-ray and gamma ray radiation with the rarified upper atmosphere and the geomagnetic field resulting an a nearly coherent, widely distributed pulse, sort of like a very large free electron maser. In more dense atmosphere where the the rays are rapidly absorbed and don't have much length to deflect, this pulse is serious attenuated, and the amount of damage done but the physical effects of the blast (shock and thermal wave) would likely make E1 effects moot. E2 is more like static electricity, and can typically be shielded by using a protected ground or faraday cage type shielding. E3 is energy that is stored in the Earth's magnetic field (similar to that which comes from coronal discharges and solar flares) and will cause longer term disruption and very high voltage spikes in large arrays like power grids; again, not much of a threat to microelectronics.
    So, from my point of view, the solar flares produced relatively low frequency changes in magnetic fields... Probably would take structures on the size of miles or 10's of miles to capture the energy (1/4 wave length or larger?).

    Here is a wiki entry for geomagnetic storms:
    Electric grid When magnetic fields move about in the vicinity of a conductor such as a wire, a geomagnetically induced current is produced in the conductor. This happens on a grand scale during geomagnetic storms (the same mechanism also influences telephone and telegraph lines, see above) on all long transmission lines. Power companies which operate long transmission lines (many kilometers in length) are thus subject to damage by this effect. Notably, this chiefly includes operators in China, North America, and Australia; the European grid consists mainly of shorter transmission cables, which are less vulnerable to damage.[12]

    The (nearly direct) currents induced in these lines from geomagnetic storms are harmful to electrical transmission equipment, especially generators and transformers — induces core saturation, constraining their performance (as well as tripping various safety devices), and causes coils and cores to heat up. This heat can disable or destroy them, even inducing a chain reaction that can blow transformers throughout a system.[13][14][15] This is precisely what happened on March 13, 1989: in Québec, as well as across parts of the northeastern U.S., the electrical supply was cut off to over 6 million people for 9 hours due to a huge geomagnetic storm. Some areas of Sweden were similarly affected.
    According to a study by Metatech corporationI][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I, a storm with a strength comparative to that of 1921, 130 million people would be left without power and 350 transformers would be broken, with a cost totaling 2 trillion dollarsI]not specific enough to [URL="http://en.wikipedia.org/wiki/Wikipedia:Verifiability"]verify[/URL][/I.

    By receiving geomagnetic storm alerts and warnings (e.g. by the Space Weather prediction Center; via Space Weather satellites as SOHO or ACE), power companies can (and often do) minimize damage to power transmission equipment, by momentarily disconnecting transformers or by inducing temporary blackouts. Preventative measures also exist, including digging transmission cables into the soil, placing lightning rods on transmission wires, reducing the operating voltages of transformers, and using cables that are shorter than 10 kmI][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I.
    I do not believe that an off-grid solar array, backup generators, inverter, etc., would be susceptible to a solar flare event.

    For grid tied systems--there may be a risk of damage from surges on power company transmission lines entering the home electrical system (guess on my part).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Inverter Recommendation

    I am going to work on putting together a system for your review..Inverter...Batteries
    and Generator. I ordered a eu2000i from Mayberry's to at least feel I am making some progress and the reviews on them are great to say the least.

    My Uncle just retired from NASA in Dec and their research scares me a little. Yes I get a little better info then the public but not enough to make big costly changes.
    I am going to put this system together for peace of mind for brownouts, Utility loss
    and anything mother nature can throw at us..at least I hope too.

    I still have a lot to learn and love it. This forum is the best place to this.



    Thanks all... Mike
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Inverter Recommendation

    invertermike,
    i'd be curious to hear some of those tales from nasa in a pm. if you decide to put those stories on the forum it would have to go up in the opinion area and you'd be subjected to this tough crowd even relaying what you were told.:cry: i want to hear some of the scuttlebutt in any case.
  • Ralph DayRalph Day Solar Expert Posts: 986 ✭✭✭✭
    Re: Inverter Recommendation

    Me too!! Lots of us too!!:p

    Ralph
  • RandomJoeRandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: Inverter Recommendation

    Back to inverters, I just recently installed an Outback VFX3648 inverter/charger. I already had the FM-80 charge controller, FNDC battery monitor and Mate interface to go along with it. I now have it wired basically like an oversize UPS. Grid goes in to the inverter, a small breaker panel off the inverter feeds my "backup" circuits. (Right now, that's fridge, office/ham bench, and server closet.)

    It switches back and forth between battery/inverter and grid power daily, sometimes a few times per day if it's cloudy. Haven't had a bit of trouble with any of the computers. In fact, most of the time I'm not even aware it switched! Every once in a while the CFL desk light will "blink" one pulse.

    Just occurred to me, reading this thread, that I have NOT tested "grid failure" to see how that works. I'm hoping it won't be a problem - there is an adjustment in the VFX inverter that tells it how many cycles to wait on grid failure before switching. It defaults to 60 cycles (a whole second!) which obviously would make a computer unhappy, but can be set down to 0 (not sure what that would do). I set it to 6, but - again - haven't tested it! I'll have to do that soon.

    Edit:
    Heh... Just went out and killed the grid power to the inverter. Not even a blink! Heck the sound of the relay clicking in the inverter was audibly indistinguishable from my flipping the switch. I'm happy! :cool:
  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Inverter Recommendation

    Generally, UPS's will need to detect and switch in 1 cycle maximum (16 milliseconds, typically 2-10 msec).

    1 cycle carry through (16.6 msec) is all a normal power supply is spec'ed for.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: Inverter Recommendation

    I wouldn't mind seeing some of the NASA stuff on the open board, so long as it was understood that he's just passing stuff on and isn't to be held responsible for it or be expected to prove it, and provided he can do so without getting anyone into trouble.
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Inverter Recommendation
    niel wrote: »
    i want to hear some of the scuttlebutt in any case.

    Sounds like a new board title - scuttlebutt I'd read it!
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Inverter Recommendation

    we do have an area for that mike. it's where the rss feeds are, but could go in the opinion area too.
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