Generator technical question

jcheiljcheil Solar Expert Posts: 722 ✭✭✭
OK, so I am going to invest in a larger generator with auto-start capabilities.

I am 99% sure I am going to go with a diesel for a number of reasons. One being, I can't get propane delivered to me and using 100lb tanks would be a real pain. The other being, I can buy off-road diesel here for below street prices (about $3.00/gallon now which is even cheaper than unleaded). I also like the longevity of the engines and the rather quiet nature of them being low RPM engines.

From reading on here, I remember a formula for determining the proper sized generator. I would pretty much only be interested in it for those rare times that we get several cloudy days. Right now I can get by with my little 3500 gas powered one, it works fine for my loads and the internal charger on the VFX3648.

But my new system will be a dual VFX3648. I believe they each have a 45a charger built in and I hear they are pretty good PF corrected. Given that I have a 740ah of battery bank, a 13% charge rate would mean I need 96-ish amps. That means pretty much both charges at full power.

However I can't seem to find/remember the formula to determine the proper sized generator, especially using a diesel where I remember people saying you need to run it at least 50% load.

Please correct me if anything I said above is wrong and I appreciate any help (and opinions) anyone else might have on this subject.
Oh yeah, and I do have an FNDC, so I would need to know what "else" I would need to get the "auto-start" thing to work.

Thanks!
Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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Comments

  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    But my new system will be a dual VFX3648. I believe they each have a 45a charger built in and I hear they are pretty good PF corrected.
    <snip>
    Please correct me if anything I said above is wrong

    The VFX chargers are not PF corrected. Forum member 'Crewzer' tested them and found that the PF was very high if the generator input was a good sine wave.

    Sorry, I can't help with the AGS... there are some good threads over at Outback's forums about FNDC and AGS.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Generator technical question

    The formula I use to ESTIMATE power for charging at 50% of generator capacity:

    45 Amp charger * 59 volts charging * 1/0.90 PF (guess) * 1/0.85 Charger eff (guess) * 50% generator loading = 6,941 VA Generator rating

    If you look around, you may find some numbers about AC charging efficiency.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,571 ✭✭✭✭✭
    Re: Generator technical question

    generally, when running the generator, the inverters transfer switch goes to Pass Thru, and your loads run off the generator. And then,, in addition to your house loads, the inverter's charger will pull some (adjustable?) amount of power from the genset.

    if the sun shines through some clouds, you can really give your batteries a hefty charge, so beware of this being able to happen.
    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 ,

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Generator technical question

    You won't get "96 ish" Amps from two 45 Amp chargers. You also don't really need that much. 90 Amps will be more than enough. Do not worry about the supposed "poor power factor" of the FX inverters either.

    FX chargers rate in AC Amps with an approximate conversion factor of 2.5 for a 48 Volt system. So full power on the 3648 is 18 Amps AC. Multiply by 2 and you've got 36 Amps or 4.3+ kW just for the charging. As Mike said the loads are pass-through so allocation must be made for them as well. If these inverters are in series you can run 240 VAC gen for them, but if they are paralleled the wiring becomes more difficult (and even worse if there is an autotransformer used to balance the loads between them). Outback has tons of wiring diagrams for these, including the many variations of series/parallel stacking with gen input.

    One of the best things about the Outbacks is that you can program the maximum gen current and the maximum charge current, which can allow you some flexibility in balancing the gen capacity to the loads & charging: priority is given to the loads and the charge rate will decrease to allow up to all the available input current to loads, taking for charging only what is available above that. Nor do their chargers have large inrush current or demand 100% to start then taper down: they start at zero charging and ramp up to what is available staying below the maximum setting.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    If these inverters are in series you can run 240 VAC gen for them, but if they are paralleled the wiring becomes more difficult (and even worse if there is an autotransformer used to balance the loads between them). Outback has tons of wiring diagrams for these, including the many variations of series/parallel stacking with gen input.

    They will be configured in a stacked configuration to produce 240v. In addition I am using the X240 transformer to balance the loads (per Outback Support).
    They stated that this is the best configuration because If the 240V loads (or total loads) do not exceed the output of the master inverter, the slave will go to sleep and the X240 will provide the 240v. If the slave inverter needs to wake up, it will start contributing to the 240 as the second leg and the transformer will help to balance both of the legs.

    This sounds like a perfect setup because technically if one inverter dies, I can still have 240 (albeit at a reduced max load).
    Also, I currently have only 120v generators, and Outback support said they can still be used in this setup, but only the master inverter will be able to provide charging current. The slave will see that the master is on AC and activate its transfer switch and basically do nothing (since there is no second leg from the generator hooked up to it).

    I do want to get a larger 240v generator (the putpose of this thread), but it is nice to know I have some flexibility in case the 240v generator dies.
    If anyone has experience with this kind of setup please let me know. I would hope Outback support knows what they are talking about :)
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Generator technical question
    jcheil wrote: »
    I do want to get a larger 240v generator (the putpose of this thread), but it is nice to know I have some flexibility in case the 240v generator dies.
    If anyone has experience with this kind of setup please let me know. I would hope Outback support knows what they are talking about :)

    They do, and all that you were told is correct.

    But it means the charging is limited to one 45 Amp charger as the second inverter will not have its charger powered when AC IN is active. You can not power it from the same generator @ 120 VAC or from a different one (which would be out of sync). This severely limits the charging capacity. So whenever AC IN is active (charging) you have only half power available for loads too (albeit 240 VAC).

    How to get around this: connect second generator to stand-alone charger hooked up to battery bank. This gives extra charging capacity and reduces load demand on first generator. Alternately wire in a transfer switch to take loads to second generator removing them from the first and increasing its available charging capacity.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    How to get around this: connect second generator to stand-alone charger hooked up to battery bank. This gives extra charging capacity and reduces load demand on first generator. Alternately wire in a transfer switch to take loads to second generator removing them from the first and increasing its available charging capacity.

    Cool ideas, thanks!

    Hopefully the new 240v generator will not break down and I will never have to resort to using the 120v generators anymore.
    And I did over-panel a bit, so with major conservation during periods of little sun, when (if) the generator goes down, I think I would be able to get by.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • mike95490mike95490 Solar Expert Posts: 9,571 ✭✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    Cool ideas, thanks!

    Hopefully the new 240v generator will not break down and I will never have to resort to using the 120v generators anymore.....

    That's right, the preferred generator never breaks down. I use a autotransformer to boost a small 120V genset, to 240 for the inverter. That runs my 300W baseline for a long time off a 2000w inverter genset
    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 ,

  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Generator technical question

    Mike, can you expand a bit on how you have the 2 inverters set up/ wired and does the larger inverter supply 240 or just 120, then through the Xformer?
    tks
     
    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
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question

    Another quick question. If I end up with a gas generator (rather than a diesel) with auto-start, but it does NOT have an auto-choke, is there a generic "aftermarket" way of providing auto-choke?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Generator technical question

    Some people have done their own little solenoid to pull on the choke lever.

    I would suggest looking for generators with electronic engine computers--Those (typically?) managing all fuel related needs--Including choking.

    The Honda EM4000SX has an engine control module (no choke). The non "SX" version has a manual choke.

    The Champion products (at least those in the 7kW+ line?) also have automatic choke.

    What size genset are you looking for?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    BB. wrote: »
    What size genset are you looking for?

    -Bill

    Based on your calculations, I am thinking along the lines of a 10-12kw.

    I want to be able to run the max charge rate (that my batteries can handle and the 2 VFX 3648's can put out) and my potential max 240V AC loads of perhaps 2-2.5kw at any one given time, so that I can run it for the shortest time possible and keep the generator loaded below 80%.

    I can't swing the $10k for a diesel. Nothing I find in the big gas 10k+ have "auto-choke" except some cheap off-brands.
    I want full-pressure lubrication, auto-fuel shut-off, AVR, < 5% THD, etc. None of the off-brands have all of that combined.
    Best bet so far is: http://www.homedepot.com/p/Powermate-12-500-Watts-Gasoline-Powered-Electric-Start-Portable-Generator-with-Subaru-Engine-PM0601250-01/100676597?N=5yc1vZbx9nZ2bctka
    ...which has EVERYTHING I need except the auto-choke.

    Now, being here in FL, it RARELY gets cold, so I wonder if perhaps it would start anyways without the choke closed after just a bit more cranking? I currently have pull-start motors and KNOW I have to choke it pretty much every time otherwise I would have to yank on it 10+ times. But with electric start, maybe that won't matter?

    Suggestions/experience always welcome.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    I currently have pull-start motors and KNOW I have to choke it pretty much every time otherwise I would have to yank on it 10+ times. But with electric start, maybe that won't matter?
    It will matter. Have you considered propane generators? (not conversions, real factory designed propane generators). I believe there are a couple on the market that meet your criteria.
    jcheil wrote: »
    Based on your calculations, I am thinking along the lines of a 10-12kw.

    I want to be able to run the max charge rate (that my batteries can handle and the 2 VFX 3648's can put out) and my potential max 240V AC loads of perhaps 2-2.5kw at any one given time, so that I can run it for the shortest time possible and keep the generator loaded below 80%.

    What's the rush to charge the batteries at the max rate possible? If you charge at a lower rate, it just takes longer, but it does not use more fuel. Running the chargers flat out continuously isn't great for them either.

    I think you would be better off with a smaller generator. Your inverters do a great job of protecting the generator from overload. For example, if you have a 5000 watt generator, you program the inverter to allow up to 5000 watts for charging and loads. If your chargers were humming along pushing 4500 watts into your battery, and the well pump cycles on, the inverter/charger will instantly cut back on the charging until the pump cycles off.

    BUT, as Cariboocoot explained you can only use one charger in your configuration. Therefore you will not be putting more than 3000 watts into the batteries anyway.

    A 4-6 kw Honda generator will allow full charging and run your AC loads. You might consider inverter generators in that size range... the Honda eu6500i is incredibly quiet. If you want to add a bit of extra battery charging while the generator is running, just buy a standalone battery charger and power it from the generator. If, for example you have a 5000 watt generator and a 1000 watt standalone battery charger, you program the VFX to think there is a 4000 watt generator.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    vtmaps wrote: »
    It will matter. Have you considered propane generators? (not conversions, real factory designed propane generators). I believe there are a couple on the market that meet your criteria.

    I'd love to get one, unfortunately, I cannot get propane delivered here. I have tried every possible way to get it. I was even going to get a 250g tank, mount it on a trailer and tow it to the "main road" (at the edge of the private property) to have them fill it (which keeps me OK with DOT because I would not be towing it on ANY public roads), but every propane company I speak with will not do it. They all claim that you have to be a licensed gas tech to "make the connection" from the tank to the device. My argument is that millions of people are not gas techs who use barbecue grills and connect those tanks :) The best I could do would be to get 100lb tanks and bring them to town to be refilled and they won't last very long running a larger generator. I'd spend my life lugging those heavy things back and forth all the time.

    vtmaps wrote: »
    What's the rush to charge the batteries at the max rate possible?
    Hmmm...I guess I have (mis-)read that here? I was under the impression that the goal was to always try to minimize generator runtime and provide the most charging current possible to "bulk up" the batteries, then let the solar finish them off. I am "well" paneled, and predicting minimal generator runtime usage anyways (fingers crossed).

    But now you have me thinking again...The Honda (the new model is the 7000is); I have looked at. And I believe it is 240V also so I could run both chargers (although not at full rate). I'm not too concerned about quiet, but it's a real nice generator, although $4k - ugh :(
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    I was under the impression that the goal was to always try to minimize generator runtime and provide the most charging current possible to "bulk up" the batteries, then let the solar finish them off.

    My goal is to minimize generator fuel cost. What matters is how much fuel is used to produce a kwh. Some generators are rated for 'prime' or continuous use... they can be run at 100% of their prime rating continuously. Those are likely to be your most efficient generators. The Honda's rank pretty high in that regard.
    jcheil wrote: »
    And I believe it is 240V also so I could run both chargers (although not at full rate).
    Why couldn't you run both chargers flat out if you wanted?

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    vtmaps wrote: »
    Why couldn't you run both chargers flat out if you wanted?
    --vtMaps

    I believe, based on the math done for me earlier in this thread, showed that I would need basically the max of the 2 vfx3648 chargers (45a each, 90a total) to be at a 12% charge rate for my 74-ah bank and that I would need a generator capable of outputting 36amps + my loads (perhaps 2kw). That rounds off to about 40amps, and keeping a generator at max of 80% load means I would need one capable of 48-50amps - thus putting me in the $12kw generator range. The Honda is only 6500 continuous which leaves me a little less than helf-short of what I would need. Again, assuming that I am understanding everything correctly.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Generator technical question

    Be careful you aren't getting mixed up with VA & W.

    90 Amps to 48 Volts is about 36 Amps at 120 VAC, but only 18 Amps at 240 VAC. Same Watts either way: 36 * 120 = 4320 Watts; 18 * 240 = 4320 Watts.

    With the dual inverter-chargers running you would be using a 240 VAC generator at (roughly) 18 Amps. So in fact the 6500 would do it providing the loads combined with charging didn't exceed its rating. Fortunately the Outbacks will simply dial back the charging as-needed when loads go up (providing it's not too sudden of an increase). You don't want to buy twice the generator you need or else instead of running it at 80% capacity you'll be running it at 40% capacity for the same power.
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    I would need basically the max of the 2 vfx3648 chargers (45a each, 90a total) to be at a 12% charge rate for my 74-ah bank and that I would need a generator capable of outputting 36amps + my loads (perhaps 2kw). That rounds off to about 40amps, and keeping a generator at max of 80% load means I would need one capable of 48-50amps - thus putting me in the $12kw generator range. The Honda is only 6500 continuous which leaves me a little less than helf-short of what I would need. Again, assuming that I am understanding everything correctly.

    I don't see it that way... if your chargers are putting out 90 amps at 59 volts, that's 5310 watts. Of course, the charger is not 100% efficient, so maybe you need 6000 watts from the generator. Whether or not you need to run the generator at only 80% of its rating depends on the generator. Honda generators have a continuous rating that is less than their nameplate surge capacity, but they can be trusted to run at 100% of that continuous rating.

    As I mentioned earlier, there is no need to charge at 12 or 13%. It will not save any fuel to charge faster... what matters is to keep the generator fully loaded. A smaller generator is easier to keep fully loaded, and if your AC loads diminish your charging for a few minutes, so what?

    Bottom line: a 4-6 kw generator is the correct size for your system.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question

    Yes thank you both, you clarified that for me. I was getting the two W/VA things messed up.

    I am now thrilled to know that I can do it with a smaller generator. And I just checked, the new Honda ue7000is is rated 5500 continuous so I think that would be a good fit. So the only question now is...$4k - ugh... Decisions decisions...
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question

    Update: Just clicked the PLACE ORDER button for the eu7000is over at ElectricGeneratorDepot.com. $3,789.99 free shipping.

    I value everyone's opinion here and decided to just "do the right thing" :)
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    jcheil wrote: »
    I am now thrilled to know that I can do it with a smaller generator. And I just checked, the new Honda ue7000is is rated 5500 continuous so I think that would be a good fit. So the only question now is...$4k - ugh... Decisions decisions...

    I think Bill gave you some very good advice here:

    BB. wrote: »
    I would suggest looking for generators with electronic engine computers--Those (typically?) managing all fuel related needs--Including choking.

    The Honda EM4000SX has an engine control module (no choke).

    You will not max out your two inverters with the EM4000SX, but that's not a bad thing. While charging, you will be able to run any of your AC loads seamlessly. You will always run the generator at its prime rating. Conventional generators are more efficient than inverter generators of the same rating. (only when the two generators are lightly loaded does the inverter generator become more efficient than the conventional generator).

    The EM4000SX costs less money to buy and will save you money on fuel because you always run it efficiently at prime capacity. The only downside is that you may need to run it an hour longer than the bigger generator... is that such a bad downside?

    --vtMaps

    EDIT: I see that you've ordered the 7000. Congratulations! it is a marvel of engineering.
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    vtmaps wrote: »
    EDIT: I see that you've ordered the 7000. Congratulations! it is a marvel of engineering.

    Yeah seems amazing. Fuel Injection (in addition to the Inverter part) was likely the main reason I finally decided to click "Buy". I'm so done with carbs.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: Generator technical question

    Hi jcheil,

    Have two gensets connected to the power system at one site.

    The Diesel is connected to AC2, and a Honda EU6500isa to AC1 -- I really like the Honda EU gensets. The ONLY problem I have with the 6500 on AC1, is that when the venerable Xantrex SW+ Inverter/Chargers reach a voltage regulated stage -- Float, or EQ --, the Honda's AC output can be dragged out of voltage regulation by the SW+es dumping some excess current INTO the AC imput. Have not tried the Honda on AC2, but just bet that this issue goes along with the bi-directional nature of these older Low Frequency inverters.

    Believe that the Outback inverters are not purely Low Frequency inverters, and, of course some folks strictly Bulk ONLY with gensets ... but, often like to run the genset about 25% of the expected Absorb stage before shutting it down.

    Do not want to cloud the waters, now that you have ordered that great new genset, and believe that Marc/coot runs an EU2000 genset on his OB inverter, without complaint.

    Every inverter/charger behaves a bit differently, and, with two gensets in use, it is very nice to use the internal transfer switches (they are very fast) to choose which generator gets used.

    All-in-all, the 6500 has been a very nice and capable generator. The 7000 should be a nice advance on the 6500.
    FWIW, Good Luck with the new system ... sounds like you are covering all the bases on planning it. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    Vic wrote: »
    Every inverter/charger behaves a bit differently, and, with two gensets in use, it is very nice to use the internal transfer switches (they are very fast) to choose which generator gets used.

    Could you explain this a bit? I was also going to set up the ability to switch between generators rather than use both at the same time (in case one was down), but I was going to do that at a small breaker panel (with a lockout) to determine which generator is "connected" to the inverters at any given moment.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: Generator technical question

    Hi jc,

    Well believe that your OB inverters also have the ability to take Grid power on AC1, and generator power on AC2, and use the internal transfer switches to use either source.

    So, because the inverter gensets look as good a Grid, use that one on AC1, and use a standard genset on AC2. Normally, only one genset is active at any one time, so there should no need to set priorities, but am sure that that capability also exists in the OB inverters.

    FWIW, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Generator technical question

    The Outbacks do not have a AC1 and AC2 they have selectable inputs ( Grid or Gen ) under setup. You can have two generators hooked up and select which input you want. With the " G " series the Grid is by directional, but is non functional in the VFX models. The Grid selection has a little different way it handles the float, it has a float and re float setting and Gen does not, The grid can be defeated by putting 24 hrs in the float time.

    You would still need a manual transfer switch, but if you have 2 generators you can have two different settings in the Inverter and switch back and forth depending what Generator you choose to use. My 20 kw is called Grid and my Honda EU 2000 is called Gen. Push a couple buttons and the settings ( ACin amps & Charger amps ) are in force.

    One thing I didn't mention is the AGS, I have no experience with it. there a ton of settings and it may only work on the GEN input. The FNdc has the SOC settings to trigger the AGS and maybe voltage or that is triggered by the Inverter. You have new batteries and until they get up to full capacity, I'd use the default settings or you'll be doing lot's of knee jerks trying to get it all sorted out. With my new batteries I was having to use 11 amps ending 2 months ago and now I have them up to 30 ending amps and 1.265 SG level.
    .
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: Generator technical question

    Thanks Bc04 for the OB detail. Have never set hands on one.

    JCheil, sorry for the inaccurate opinion. Have Fun, and Thanks, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Generator technical question
    You would still need a manual transfer switch, but if you have 2 generators you can have two different settings in the Inverter and switch back and forth depending what Generator you choose to use. My 20 kw is called Grid and my Honda EU 2000 is called Gen. Push a couple buttons and the settings ( ACin amps & Charger amps ) are in force.

    Now that's a cool idea. I have a heck of a time with that now switching between two generators. I always have to remember to go to the mate3 and change the generator input current limit.
    One thing I didn't mention is the AGS, I have no experience with it. there a ton of settings and it may only work on the GEN input. The FNdc has the SOC settings to trigger the AGS and maybe voltage or that is triggered by the Inverter. You have new batteries and until they get up to full capacity, I'd use the default settings or you'll be doing lot's of knee jerks trying to get it all sorted out. With my new batteries I was having to use 11 amps ending 2 months ago and now I have them up to 30 ending amps and 1.265 SG level.
    .

    That was gonna be my question for next week. If anyone has suggestions on the best way to do AGS. I am thinking I need an AGS controller of some kind??? But like I said, I can hold off on that question until next week when everything is finished being installed.

    And Vic, no worries, I VERY much appreciate everyone's help/input.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Generator technical question
    My 20 kw is called Grid and my Honda EU 2000 is called Gen. Push a couple buttons and the settings ( AC in amps & Charger amps ) are in force.

    I have also done that with two generators, but when I switched inputs from gen to grid, the AC in amps changed, but the charger amps stayed the same. Am I missing something? Is that a mate3 thing? (I have a mate, not a mate3).

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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