Poor man's true sine wave invertor

steel
steel Registered Users Posts: 5
What are your thoughts on using an APC SmartUPS say a 2000 or 3000 watt model as a poor man's TSW invertor?

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Poor man's true sine wave invertor

    This question reappears on the forum periodically. You can search for the other discussions, but the short answer is: a UPS is not designed for continuous use and won't hold up under such conditions.

    If you want an inexpensive sine wave inverter, take a look at the Samlex line: http://store.solar-electric.com/sasiwain1.html

    The important question is: what do you want the inverter to do?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Poor man's true sine wave invertor

    If you need a fairly large UPS -- They will work OK. Battery replacement every couple years.

    If you are also trying to save energy--I would double check the "real efficiency" of an off-the-shelf UPS with the loads that you actually be using... Both when on AC power and running from battery (if you are going to ad a large external battery bank).

    Also, there can be other issues... Many inverters require manual start and/or AC power to initially power on. Neutral/Ground bonding on the AC side may be required too. The internal battery charger is sized for the batteries that come with the unit. You use different batteries--the voltages may be set incorrectly and you may have charging issues (charger too small, etc.).

    In the end--you can sometimes get these cheaply from old computer centers. They are OK for what they are designed to do and can be fun to play with. However, as the center of an Off-Grid (or even a "real" emergency standby power) system--I would not count on them working reliably for years to come (and if efficiency is poor--you will end up spending much more on solar panels+batteries+genset fuel because of the waste heat).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Poor man's true sine wave invertor

    And to follow up Marc's post--Here is a very good entry level 12 volt 300+ watt True Sine Wave Inverter from Morning Star.

    A 2-3kW inverter system is a "BIG" amount of power... Assume you run it at 1kW x 24 hours = 24 kWH per day... That would require on the order of 10kW of solar panels to keep up with that level of power usage... "Free inverter" plus $30,000 of solar panels and another $10-$30,000 worth of batteries.

    In reality, a modern 6kW GT or Hybrid or Off-Grid inverter is on the order of $4,000 or so... A relatively small part of the overall system costs (10% or less). And the 6kW Xantrex XW 6048 Hybrid Inverter (for example) is probably a lot more efficient, has nice options for battery charging from AC and Gensets and support for auto-generator control (plus battery temp sensors and logging options).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • peterako
    peterako Solar Expert Posts: 144 ✭✭
    Re: Poor man's true sine wave invertor

    Hi there, the cooling for this type of ups is most of the type max 20 min.
    Meaning if you want to run for a hour it will be overheating.

    next to that if you want to change the battery's this type work with 8 series connected AGM battery's meaning 96 to 112 V DC so for wind power or solar power you need special controllers ( expensive ) and the build in charger will not charge a higher rating non AGM battery.

    So forget it it is cheaper to use real inverters.

    P.S. my experience is that APC TSW is not a real true sine wave.

    Greetings from Greece8)
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    I am trying to do just that. There are some issues. The UPS has a run time calibration that really only makes sense if you are going to run a small set of batteries down, not run off a large continuously solar charged external battery bank. I am reluctant to try do this run time calibration since it involves driving your batteries into the ground, something that is taken for granted as an acceptable cost in the world of UPSs but to be avoided like the plague in off grid systems. My system does funny things. The battery charge lights on the UPS don't match with the state of charge shown by the Morningstar charge controller.

    I have left the UPS on all night with no load to see what would happen. It lasts through the night (I should hope so) with only 2 out of 5 charge LEDs lit, meaning it thinks it has only 40% power left. Then when the sun hits the panels in the morning it drops to only 1 LED lit, and that one flashing to indicate imminent failure, but will go on like that indefinitely, even as the panels charge up the batteries. There is also an alarm that can't be silenced when this happens. Somehow it is confused by other sources charging the batteries. Maybe this would be helped by the run time calibration? I can only guess what the UPS thinks is happening since the last run time cal was done with the tiny stock batteries and lasted less than 10 minutes.

    I have run a front load washing machine on it and that hardly loads it up at all. I have checked it often and have not felt much if any heat coming out of it, perhaps because of the low load.

    It makes a loud humming when on battery power. Not nearly as much when on genny power. It is also a real prima donna. Genny power's not good enough for it lots of times so it switches to battery power.

    I am thinking I should really load test the system to see what will happen but I fear abusing my batteries.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Poor man's true sine wave invertor

    Your best several options... If flooded cell batteries (likely not if UPS batteries) would be to use a hydrometer to measure the specific gravity.

    Another option would be to measure the resting voltage of the battery bank battery bank before starting your test and after (say the other night test) (battery resting voltage is 3 hours or so of no charging/discharging--roughly indicates state of charge of the bank).

    If you can justify the money, I would get a battery monitor (Victron is another good brand) so you can measure the Amp*Hours into and out of the battery bank. With sealed batteries, this is about the only way you can accurate monitor their state of charge (battery monitors are not perfect--So, they need to be reset to 100% full every so often or they drift).

    It is possible that your UPS has its own battery monitor estimating the battery bank state of charge--And using an external charger (like solar), is bypassing its own logging system and giving you invalid readings. Monitoring the battery bus voltage during discharging and charging will quickly show if the LEDs are anywhere near accurate (say estimating state of charge based on bank voltage--Or via another mechanism such as current monitoring).

    -Bill

    PS: Is the UPS a MSW (modified square/sine wave) unit, or a TSW/PSW inverter (true/pure sine wave) device? MSW units can cause motors and other electronics to buzz at ~120 Hz because of the non-sine wave output. Many UPS spec. sheets will be very "cagy" about if they are MSW or TSW devices (and they may even use strange wording that sounds like they are TSW when they are not).
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    This question reappears on the forum periodically. You can search for the other discussions, but the short answer is: a UPS is not designed for continuous use and won't hold up under such conditions.

    Some models of UPS are "online/double-conversion", including the Smart-UPS line. The inverters in these models are designed for 24/7 operation at full load, since they always convert AC-DC-AC. Like the one in my sig.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    BB. wrote: »
    If you need a fairly large UPS -- They will work OK. Battery replacement every couple years.

    ... "real efficiency" of an off-the-shelf UPS with the loads that you actually be using...

    ... Many inverters require manual start and/or AC power to initially power on. Neutral/Ground bonding on the AC side may be required too. The internal battery charger is sized for the batteries that come with the unit. You use different batteries--the voltages may be set incorrectly and you may have charging issues (charger too small, etc.).

    In the end--you can sometimes get these cheaply from old computer centers. They are OK for what they are designed to do and can be fun to play with. However, as the center of an Off-Grid (or even a "real" emergency standby power) system--I would not count on them working reliably for years to come (and if efficiency is poor--you will end up spending much more on solar panels+batteries+genset fuel because of the waste heat).

    -Bill

    You are thinking of UPSs from 10-15 years ago. The APC SmartUPS line doesn't have these issues. My bank is now 5 years old and is just now starting to die - mostly because they spent 2/3 of their life on an older UPS which didn't float them properly. My SmartUPS is 92-93% efficiency, on par with off-grid inverters. No issues with manual start, it can do a black/cold start without AC input. Neutral/ground bonding via the AC input line. Charger auto-adjusts output based on the size of the battery bank (the manufacturer allows expansion up to 10 times the internal battery size), and a special programming mode allows adjustment of the float voltage if necessary. Yes, you can get them very cheap from Ebay if you keep your eyes open. I've used two different UPSs for 5 years now as a whole-house emergency standby system.

    They are modern high-efficency inverters with built-in AC chargers designed for 10-15 years of 24/7 critical-load service. ;)
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    BB. wrote: »
    .. probably a lot more efficient, has nice options for battery charging from AC and Gensets and support for auto-generator control (plus battery temp sensors and logging options).

    -Bill

    Already talked about efficiency and battery charging. Smart-UPS has battery temp sensors and extensive logging, available via Ethernet/wifi or RS-232.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    peterako wrote: »
    Hi there, the cooling for this type of ups is most of the type max 20 min.
    Meaning if you want to run for a hour it will be overheating.

    next to that if you want to change the battery's this type work with 8 series connected AGM battery's meaning 96 to 112 V DC so for wind power or solar power you need special controllers ( expensive ) and the build in charger will not charge a higher rating non AGM battery.

    So forget it it is cheaper to use real inverters.

    P.S. my experience is that APC TSW is not a real true sine wave.

    Greetings from Greece8)

    Inaccurate. Again, Smart-UPS is designed for continuous duty. Different sizes use different input voltages. Below 3000 watts uses 48 volts if I remember right, 3000 to 6000 uses 192 volts, above that uses 384. And not true sine wave, are you kidding? They are designed to support critical loads with power better than the utility supplying it!
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Poor man's true sine wave invertor

    Since he's looking for something cheaper than a conventional inverter it is doubtful he'd be looking at a continuous UPS. Most likely he was considering one of those inexpensive back-up units. As such both peterako and my comments are accurate. Do not bring up "yes but you can get them cheap used" because by the same token you could get a standard inverter used for less than new price.
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    MarkP wrote: »
    I am trying to do just that. There are some issues. The UPS has a run time calibration that really only makes sense if you are going to run a small set of batteries down, not run off a large continuously solar charged external battery bank. ... Somehow it is confused by other sources charging the batteries. Maybe this would be helped by the run time calibration? I can only guess what the UPS thinks is happening since the last run time cal was done with the tiny stock batteries and lasted less than 10 minutes.

    ... It is also a real prima donna. Genny power's not good enough for it lots of times so it switches to battery power.
    .

    The calibration auto-adjusts while on-battery. When I'm driving my UPS from my Prius, where the input DC voltage fluctuates from 200-244 volts coming from the traction battery, the "time left on battery" changes from minutes to hours. However, the calibration doesn't mean anything, it is just there to give you that little timer. In the end it will shut down when the battery voltage hits critical, around 10.5 volts per 12 volt battery (about 165 in my system). Ignore the calibration.

    You need to adjust the slew rate in the system menu. I think on mine the largest value is 60 Hz +/- 3 (stock value is +/- 0.1), which keeps in-sync 99% of the time. Yours probably isn't switching to battery power since they are designed to stay off battery even with wild frequency and voltage fluctuations from the utility, what you are seeing/hearing is the warning that it has gone "off-sync" and won't drop the load on bypass to the genset if for some reason the UPS fails. Until it syncs again, then the warning goes away, eventually it looses sync again, repeat.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor
    Since he's looking for something cheaper than a conventional inverter it is doubtful he'd be looking at a continuous UPS. Most likely he was considering one of those inexpensive back-up units. As such both peterako and my comments are accurate. Do not bring up "yes but you can get them cheap used" because by the same token you could get a standard inverter used for less than new price.

    The *OP* said he was looking at a APC SmartUPS. That is an online inverter, not an inexpensive back up unit.

    *BB* talked about getting one used... "you can sometimes get these cheaply from old computer centers". I was confirming that.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    Spent 20 minutes writing a post then it disappeared.

    I have a SmartUPS 3000. Some models are designed to accept multiple external battery packs to increase capacity. This is not one of them but it is all I have. I took out the tiny batteries and connected eight 6-volt golf cart batteries from Costco that are rated at 220 AH capacity. The UPS itself is rated for 3,000 VA or 2,700 watts.

    I ran a load test last night with two 500 watt halogen work lights as load. It lasted somewhere between 6 hrs and 9 hrs then shut down automatically. When I woke up at 3:30 am it was still running. At 6:30 am it had shut down. I forgot to check if the lights were still hot so I don't know how much later than 3:30 the test ran but I suspect I woke up when the lights went off and the noise from the UPS stopped. Call it 8 hrs.

    The poor UPS is out of its normal element and many of its features such as alarms and battery status readout don't work well with the external charging system but the batteries take a charge and the UPS sucks DC and makes AC until the batteries run down so I should stop looking at the lights. I already pulled off the little piezo beeper. It will black start with only battery power. So far it "works".

    If paired with a little Honda EU1000i it switches to battery if the load gets too high. Relieved of the load the Honda "catches up" and the load switches back, only to drop out again since the little genny can't carry the load. The UPS/genny sit there swapping back and forth. The UPS was obviously not designed to deal with such an interactive load. When the grid goes down it doesn't come back just because the UPS took the load for a while. That being said I will try to reduce the sensitivity of the UPS to voltage and frequency variations.

    As part of my system I have a 48 volt golf cart charger. The little Honda EU makes the amps needle dance like crazy. This is really pronounced when charging at high rated onto a discharged battery bank. My other old fashioned Generac 3500xl with the mechanical governor does not cause this problem. The Honda EUs are good for some things but the EU1000i doesn't work with the golf cart charger for some reason.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Poor man's true sine wave invertor

    Do you know what the output voltage/current is for the AC Charger?

    Does the eu1000i act the same if the ECO throttle is on or off?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    The charger is for a 48 volt golf cart. It puts out whatever is appropriate for that, probably about 55 volts. It is rated at 17 amps max and that is what it went to when I plugged it in after my load test to recharge the thoroughly depleted batteries. It doesn't matter whether the Honda is in eco-mode or not, it is still too small to keep up and even when the UPS doesn't cut it loose it makes the amps needle on the charger dance like crazy. At full amps output on the charger I can even hear the Honda cutting in and out a few times per second.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Poor man's true sine wave invertor

    The VA rating for a "typical" charger would be:

    55 volts charging * 17 amps * 1/0.80 charger eff * 1/0.67 Power Factor = 1,744 VA

    The little eu1000i is rated about 900 Watts/VA max continuous. So, about 2x the rated output.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor

    MarkP, sounds like you have the SU3000 and not the SURT3000. http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=SU3000
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    The unit I have was made by Dell. I have been using it with some regularity for the last 3 or 4 weeks. I have seen no problems from operating continuously on battery power but to be fair I have not loaded it over 1000 watts except possibly for short bursts running power tools.

    While idling it makes a gawdawful buzzing sound. That is reduced greatly as you add load.

    I did manage to load up software that allowed my to minimize the sensitivity to incoming voltage. I thought that this would allow me to run one of the 500 watt work lights while running the eu1000i through the UPS. Strangely although the little Honda will run the work light with capacity to spare (slows down when eco mode is engaged) when plugged in directly, the genny bogs down and overloads when the UPS is in the loop. I am not sure why that is. The UPS does not seem to be throwing off excessive heat. I mean it would have to be dissipating 300 or more watts to consume the full 800 watt output of the genny while only putting out 500 useful watts. The following points might explain what is going on:

    The Powerchute software shows the incoming voltage to be as low as 80 volts while the output of the UPS is at 104 volts. This is due to the power conditioning features of the SmartUPS. Good for maintaining a constant power output to the end user but results in greater load on the generator. The resistance load of the light alone would decrease as the genny loaded up and voltage sagged. The UPS doesn't let that happen. I was greatly surprised to see that the inverter in the generator let the voltage go so low without tripping. I have only ever tripped the generator while operating a big circular saw. When feeding the UPS it was always the UPS that cut the genny off before the genny itself cut loose.

    The UPS is also charging the batteries. I wish I knew at what rate.

    The UPS obviously must have some losses.

    Not having ever owned a proper inverter designed for this purpose I don't know what I am missing, but I would so far rate this experiment as a success. My primary complaints have mostly to do with feeding a generator through the unit.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Poor man's true sine wave invertor
    MarkP wrote: »
    Not having ever owned a proper inverter designed for this purpose I don't know what I am missing, but I would so far rate this experiment as a success. My primary complaints have mostly to do with feeding a generator through the unit.

    80 Volts in and 104 out?
    What you're missing is about 16 Volts.

    Not something I'd use, but what do I know?
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Poor man's true sine wave invertor

    Yeah, that doesn't sound right. As long as the input voltage is within its normal operating range the output should be a solid 120 volts. Typically the window is between 50-140 volts.

    Are you sure that isn't MSW output? Measuring MSW with a cheap voltmeter would give you inaccurate readings. MSW would also explain the buzzing, possibly.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    It's a SmartUPS 3000. That's true sine wave. It passes the line voltage through until such voltage no longer meets the minimum setpoints, while at the same time trimming or boosting the voltage somewhat to condition the power. I minimized the sensitivity so it was taking crap in and putting out somewhat less crappy crap but still passing the line voltage through. Before I adjusted the sensitivity down it would have gone straight to battery and put out decent power. I did not select the various components and settings because I consider such crap desirable. I am merely commenting on how the system behaves. Earlier reports suggested that the UPS would overheat after a short time. It doesn't. The essence of my post is that the eu1000i is not up to the job, but even so the UPS is putting out better power than it is taking in. I have the choice of setting the sensitivity low and watching the generator struggle or setting sensitivity high and having the UPS/genny couple buck and hop like someone driving a stick shift when they don't know how, that is until I unplug and let the UPS just act as an inverter. It does so quite well enough so far. It will run several hundred watts for hours at a time. Just don't look at the lights on the front and expect them to mean anything. The one thing I can't report on is how the UPS behaves when supplying full power (2,700 watts). The voltages I reported were what the APC PowerChute software displayed and seem to be consistent with the settings I selected in that I told it to shut up and stop complaining and the fact that I am feeding crap power in. When operating as an inverter it puts out 120 volts.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Poor man's true sine wave invertor

    One problem that the generator might have only when the UPS is inline is not being able to drive a very low power factor load demanded by the UPS.

    In particular if the UPS just draws power from the peaks of the input AC waveform (either while charging the battery or because it is a dual-conversion UPS), then the harmonics or the low distortion power factor (two ways of looking at the same thing) could be drawing an instantaneous peak current that is more than the genny can handle, or that is interfering with the control system of the Honda.

    Another problem that would effect a conventional generator more severely than your inverter type Honda is instability in the input frequency or voltage causing the UPS to switch to battery power even though the generator is still running.

    Have you tried the experiment of putting the work light in the generator side of the UPS to see how well that works? That will give you some idea of whether the UPS is changing the load seen by the generator from the light(s) or just adding its own load to what the generator sees.
    SMA SB 3000, old BP panels.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Poor man's true sine wave invertor

    I agree with inetdog; check the generator output first and see if you can't "fix up" the power there. The same goes if you were running this from poor-quality utility power. Always see if you can't correct or at least reduce power problems at the source.

    It does not sound like this particular unit is a a continuous inverting type. If it were, the input power quality would have no effect on the output power quality.
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    Thanks for the comments. These are the kind of things I had not thought of. As far as I know these SmartUPSs are pure sine wave out and are not double conversion. They pass the line current through with some conditioning until the power quality parameters are exceeded then they go to battery power. The lights on the front confirm this. They have a light for line power and a light for battery power. They also have a light for trimming high voltage down and one for boosting low voltage up. I have seen all these lights on at one time or another. The software has a general status page that reports the voltage in and the voltage out, which is how I know those numbers.

    I do have a generac 3500xl that I have hooked up in the past but not since I dialed back the sensitivity. It has more power but worse voltage/frequency control. Well, at least I thought so until I saw the eu1000i putting out only 80 volts. I have seen the UPS reject both the eu1000i and the generac. It may be that the generac failed to maintain sufficient control of frequency. I'll try it again with the UPS sensitivity on low.

    As far as the eu1000i running the light directly but not through the UPS, regardless of what electronic magic is going on, the engine is producing power that has to go somewhere either as electricity or as heat. I should check more carefully whether the UPS is getting hot when running the honda/light combo. If there is somehow a really bad power factor that would cause extra heat in the generator windings, right?

    I don't run the generac unless I really need the power because it is so much louder and because everything I read says the honda is so much more fuel efficient. I think the real answer would be to get a bigger honda. An eu3000i would be the perfect match but an eu2000i would be more affordable and if powerful enough would be the most economical fuel wise.

    The honda has a floating neutral, the generac gnd/neutral is bonded. My bosch front loading washer won't run off of the honda alone but will run off of the UPS alone or the generac alone or the generac through the UPS. I don't know whether the bonded, not bonded has anything to do with it. Any thoughts?
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Poor man's true sine wave invertor

    If your EU1000i is really putting out only 80 Volts there's something seriously wrong with it. I have one, and it puts out 120 VAC with a perfectly clean sine wave. When Eco-throttle is on it will slow the engine right down and not waste power on excess heat. Power factor doesn't have much effect on the output quality from an inverter-generator.

    Check the output of your gen with a DMM to see if it is really putting out only 80 Volts. There is also always the possibility that your UPS unit is defective and not functioning properly.
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    Well my system has been through a hurricane here on the Big Island of Hawaii and is still going strong. I fixed a neighbor up with an identical SmartUPS3000, essentially the same set-up as I have except that I now have 2,100 watts of PV and he has only 720 watts. Our neighborhood lost power for a week. No difference for me since I was not on grid but he would have been out of luck without his system which his brother thought he was crazy for spending money on until the storm. Chalk up another win for off-grid solar.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    Re: Poor man's true sine wave invertor
    MarkP wrote: »
    Well my system has been through a hurricane here on the Big Island of Hawaii and is still going strong. I fixed a neighbor up with an identical SmartUPS3000, essentially the same set-up as I have except that I now have 2,100 watts of PV and he has only 720 watts. Our neighborhood lost power for a week. No difference for me since I was not on grid but he would have been out of luck without his system which his brother thought he was crazy for spending money on until the storm. Chalk up another win for off-grid solar.

    What kind of winds did you get? How are your panels mounted?
  • MarkP
    MarkP Registered Users Posts: 51 ✭✭
    Re: Poor man's true sine wave invertor

    When it hit it was on the border between hurricane and tropical storm. My neighborhood was also strangely spared. At least there was not the level of destruction and downed trees that other neighborhoods had. Anyway I think that the winds were around 60 to 70 mph. My panels were mounted using commercial hardware that I got second hand. I think I installed them per mfrs instructions which I had to deduce from web searches. Simple rails bolted to the roof parallel to the ridge line such that the panels could be mounted in portrait orientation with the rails underneath at the 1/4 and 3/4 points on the long dimension of the panels.
    15 Panels (about 3,000 watts), Schneider Conext 60-150 MPPT Charge Controller, Schneider Conext 4048 Inverter, 8 x 6-volt Costco GC-2 Batteries.
  • ZoNiE
    ZoNiE Solar Expert Posts: 100 ✭✭
    Re: Poor man's true sine wave invertor

    Hi Mark, Have you run a Microwave off of the SmartUPS on battery only?

    I'm interested in using one as the Pure sine wave inverters get expensive over 1000W and have a high waste draw at idle and all I need one that big for is to nuke a potato or something, and not want to run the genset. Then I can use a smaller 400-700 W for the usual stuff.

    These are, I'm told by the IT guys that use and sell them that they basically run on inverter output all the time, and the batteries are charged by the AC Line in as needed. Never the two shall meet...Hence super clean power for the servers...

    I occasionally come across used ones for free to very little $ and never even considered one until recently.