Generator surging (hunting) when charging sytem thru stacked SW 5548s.

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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #32
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Question ?? Is the Generator Grounded ?? If so, where is it attached. If it is, remove the ground and give it a try. Have you actually had a Kohler Tech look at it ?? Some of the governor controls have upgradeable firmware in them, some are potted. Since it's doing it on two different Generators, well, sounds more like a load issue or a loop of some kind. I'v got one right now with a solid concrete block sitting on the control box, it's the only thing that would smooth it out, sounds silly but as the vibration would increase, so would the hunting because of the stepper. One problem can exacerbate another and it becomes the chicken or the egg.

    Have you ever had the regulator on the propane supply checked ??
    .
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    #33
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Aren't generators fun? I had to put 2 60 watt lightbulbs in the control box area (about 1' x 1' x 1'). One would come on during the preheat phase and one would stay on during the generator running. If the electronics weren't started off warm, and kept warm, the thing would always error and shut down. Now that I don't use it, just exercise it, the thing will quit 50% of the time it ran on exercise and not start remotely:grr. Solution? remove the fuel cut off solenoid from the injector pump and install a spring to hold throttle in run position. To Start you use the auto-off-manual switch manually. To shut down you have to push the throttle arm down and starve/kill the engine. No longer have safety cut off available. Is it worth $500 plus for a new engine controller? Not any more (utility is my multi billion dollar generator).

    Ralph
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #34
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Generator is grounded. I will try popping off the ground for a test run. Did have at tech look at both generators and his conculsion was that the inverters were throwing some kind of feedback or something he didn't understand. We have tried isolating all the loads and it is clear this is ongoing when the inverters are charging regardless of other loads. I haven't had the propane regulator checked however I can load the heck out of the generators in bypass mode without the surging issue.........John
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #35
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    John Sullivan wrote: »
    Did have at tech look at both generators and his conculsion was that the inverters were throwing some kind of feedback or something he didn't understand.

    It's not feedback. I believe if you put a clamp-on DC ammeter on the battery cables going to the inverter you'll see where the surge is coming from. Why you can't reduce it by loading it and reducing charger amps is what's baffling.

    SW inverters, when stacked, are not master/slave. They're fully independent except for communicating with one another as to the status of their sine waves. So I find it hard to believe they could both cause a surging in unison. I think I'd disconnect the AC loads, shut the inverters down, remove the stacking cable, and test each one individually. Maybe you got a control board in one of them that has gone south.
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    Chris
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  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    #36
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    I have XW which is a newer model, but under some circumstances it does the same thing, not as pronounced though - may be 59 to 61 Hz, but I can definitely hear the sound.

    The settings in SW are probably different. In XW, there are two different settings - "AC2 Breaker" and "Max Charging Rate". If they're set close to each other, so that the existing AC loads barely fit between them, XW tries to decrease charging past "Max Charging Rate". Once this happens, it starts to oscillate (one oscillation takes few seconds). I adjusted "AC2 Breaker" higher, to a value will beyond real breaker size. I set "Max Charging Rate" lower, to 80% of the max. Now there is enough room between them to fit most of the loads, and it runs very steady. However, some extraordinarily big load may upset the balance and it starts oscillating just below the "Max Charging Rate".
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #37
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    NorthGuy wrote: »
    The settings in SW are probably different. In XW, there are two different settings - "AC2 Breaker" and "Max Charging Rate". If they're set close to each other, so that the existing AC loads barely fit between them, XW tries to decrease charging past "Max Charging Rate". Once this happens, it starts to oscillate (one oscillation takes few seconds).

    Your XW does some strange things. I have never seen that.

    The two are very different in how charging amps and max gen input amps are entered in the menus. In the SW/SW Plus the charging amps are set by how many AC amps you want to the charger to draw from the generator. In the XW the charger max amps are set as a percentage of the total rating of the charger, and if you have the bank size entered correctly it will adjust the bulk amps automatically to not exceed C/10 charge rate.

    The XW's setup is easily 3x more user friendly than the SW/SW Plus two-line LCD display. This is the maximum amount of information the SW+'s display will show at one time

    Attachment not found.
    --
    Chris
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  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    #38
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    ChrisOlson wrote: »
    Your XW does some strange things. I have never seen that.

    You need to set "AC2 Breaker" much lower to see that. Although, with the small generator, it may drop charging completely instead of trying to dial it down.
    ChrisOlson wrote: »
    In the SW/SW Plus the charging amps are set by how many AC amps you want to the charger to draw from the generator. In the XW the charger max amps are set as a percentage of the total rating of the charger ...

    At a first glance, the same thing, because the battery voltage is about the same all the time. However, with my batteries, which require 64V for charging, that does make some difference. The same charging amperes at 64V produce the whole 1kW more load than charging at 55V. If your primary concern is the current to batteries, then XW way will work better for you. But, if your concern is to have a stable load on the generator, SW method will work better.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #39
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    NorthGuy wrote: »
    You need to set "AC2 Breaker" much lower to see that. Although, with the small generator, it may drop charging completely instead of trying to dial it down..

    I got the AC2 Breaker size set at max gen surge amps (what it will deliver for 2 seconds above 58 Hz), which is 40 amps. It will infinitely vary charger amps for varying loads and switch seamlessly into Gen Support if the loads exceed the GenSupp Amps setting.

    The SW Plus was good. But the XW is night and day smoother in how it handles the generator. It can be charging at 60 amps to the batteries, throw a sudden 9 kW load at it, and it will instantly switch to Gen Support with the generator supplying 4 kVA and the inverter the other 5 kVA to meet the load, with not even a flicker in a CFL in the house. I've also found that the inverter itself will easily power a 9 - 12 kW load for at least one minute (don't know the limit yet because haven't gotten it to kick out), without Gen Support, without breaking a sweat. Been doing it all morning here, welding on a wind turbine transmission case at the same time that my wife is doing her own load testing with her domestic equipment :D
    --
    Chris
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  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    #40
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    ChrisOlson wrote: »
    I got the AC2 Breaker size set at max gen surge amps (what it will deliver for 2 seconds above 58 Hz), which is 40 amps.

    I activated Gen Support, and after I did it, it still does oscillations when loads need to be dialed down from the max charge rate because the Gen Support amps are reached, but the amplitude is probably a little bit less (if I'm not imagining). Looks like it's not so afraid of crossing Gen Support threshold than it is of crossing AC2 Breaker. Therefore it is doing regulation smoother and lets motor start spikes through, so it generally works better. My only concern is that Generac manual warns not to feed any power back to the generator. With Gen Support enabled there's a risk of backfeeding. Not very high risk, but still ...

    Did SW had two separate settings for limiting generator load, as "AC Breaker" and "Gen Support Amps" in XW?
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #41
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    NorthGuy wrote: »
    Did SW had two separate settings for limiting generator load, as "AC Breaker" and "Gen Support Amps" in XW?

    The XW is much more configurable. The SW has no provision to allow adjustment for frequency and AC2 input to take into account a generator that can deliver standby surges for a certain length of time over the level you want generator support at.

    The reason you can't backfeed a Generac Guardian with a sync'd waveform that is higher than the output of the generator (which is how gen support works) is because it has a grid power input to drive its onboard controller. It was never designed for use on an off-grid inverter and that's why Generac will void the warranty on it if they find out it was used for off-grid duty.
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    Chris
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #42
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    ChrisOlson wrote: »
    The reason you can't backfeed a Generac Guardian with a sync'd waveform that is higher than the output of the generator (which is how gen support works) is because it has a grid power input to drive its onboard controller. It was never designed for use on an off-grid inverter and that's why Generac will void the warranty on it if they find out it was used for off-grid duty.

    Regarding backfeeding a generator while in Generator Support mode:

    Actually, if you look at the currents and voltages in detail, you should see that the voltage at the Generac terminals are exactly what they would be if the generator were driving only its part of the load, with nothing else connected. The voltage at the load will be a tiny bit lower than that and the extra current needed to keep the voltage up is being provided by the inverter. It is only when the inverter tries to go into Sell mode or the controls fail causing the inverter to put out more power than the load is using that the generator will start to be backfed and will be unable to handle the reverse current. The risk of this kind of actual power backfeed (potentially causing the generator to start driving the engine and causing loss of throttle control) is what can damage the generator windings or controls or the engine. That sort of damage may be characteristically different and could lead to denial of warranty coverage.
    It is very similar in this way to using a GTI with POCO in a situation where POCO does not allow backfeed and is somehow able to detect it. As long as the total load is at least a little higher than the output of the GTI, there will not be any backfeed to POCO.
    SMA SB 3000, old BP panels.
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #43
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    I have been experimenting the last couple of days with various settings to minimize the surge/hunting problem. I bulk mode it seems the settings of Gen amps AC2 at 34 coupled with Max charge amps at 35 are the best I can find to minimize the problem, however as it moves into absorb stage these settings cause the surge/hunting issue to increase.

    I have noticed that when absorb stage is reached one inverter starts reducing charge amps while the other inverter continues to charge at max set rate. I'm not sure if this is normal or if both inverters should be ramping down together.

    I think the next run cycle I will reduce the max charge amps to 30 and increase the gen amps AC2 to as high as I can get away with, probably around 45 amps. I will see how this perfoms through the whole charge cycle...........John
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #44
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    ChrisOlson wrote: »
    It's not feedback. I believe if you put a clamp-on DC ammeter on the battery cables going to the inverter you'll see where the surge is coming from. Why you can't reduce it by loading it and reducing charger amps is what's baffling.

    Chris

    Chris, I don't understand what you mean or how the ammeter will show where the surge is coming from. Could you clarify that for me...Thanks....John
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #45
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    John Sullivan wrote: »
    I have noticed that when absorb stage is reached one inverter starts reducing charge amps while the other inverter continues to charge at max set rate. I'm not sure if this is normal or if both inverters should be ramping down together.

    SW-series inverters operate completely independently when they are stacked - other than keeping track of each other's sine waves to insure they are 180° out of phase with one another. Otherwise the chargers are independent. So it's unlikely that they will both charge at the same rates once full current is not needed anymore. Due to slight differences in the way they sample the voltage, or leg imbalance on the split-phase loads, the "strong" one will overpower the "weak" one.
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    Chris
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #46
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    John Sullivan wrote: »
    Chris, I don't understand what you mean or how the ammeter will show where the surge is coming from. Could you clarify that for me...Thanks....John

    Put a DC clamp-on meter on the battery cable going from the bank to the inverters and you'll see the amps to the bank varying - that is what is causing the surging.

    The basics of stacked SW's have not been covered here either - I hope they are both on the same battery bank and that you have only one positive cable going to one inverter and one negative to the other, with parallel jumpers from + to + and - to - on the inverters. If someone has connected them with dual sets of cables (one set of cables from the bank to each inverter), or has split the bank so they're both not on the same bank, that can cause these sorts of problems too.
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    Chris
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #47
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Ok, understood. Yup, single battery bank and wired as you outlined.........John
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #48
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    ChrisOlson wrote: »
    ... I hope they are both on the same battery bank and that you have only one positive cable going to one inverter and one negative to the other, with parallel jumpers from + to + and - to - on the inverters. If someone has connected them with dual sets of cables (one set of cables from the bank to each inverter), or has split the bank so they're both not on the same bank, that can cause these sorts of problems too.
    --
    Chris

    Well, the recommended configuration from Xantrex for SW+ stacked Inverters is to have separate cables from the single battery bank through circuit breakers to each inverter + battery connection, and separate cables for each inverter minus batt connection, often through a common Shunt. This is with NO jumpers from inverter-to-inverter.

    This allows each inverter to "see" the battery directly, and allows reasonably-sized conductors (4/0 for systems here).

    This is the most common wiring that is seen in the field in this area, and conforms to X docs. Although, there are not many stacked SW and SW+es in the area. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #49
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    Vic wrote: »
    Well, the recommended configuration from Xantrex for SW+ stacked Inverters is to have separate cables from the single battery bank through circuit breakers to each inverter + battery connection, and separate cables for each inverter minus batt connection, often through a common Shunt. This is with NO jumpers from inverter-to-inverter.

    No, not for series stacked. They must be shut down together with one DC Disconnect. Directly from the SW-series Installation Manual:

    Attachment not found.

    The reason for this is fairly obvious - you can't have a setup with independent disconnects that shuts down only half of a split-phase power system. That could be disastrous.
    --
    Chris
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #50
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    For reference, this is the wiring diagram for the AC side of those inverters with the ISC-S cable used.

    Attachment not found.

    --
    Chris
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #51
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Chris,

    Well, looking at the SW+ docs, the speced approach is just as I described above. The DC breakers on the batt cables are independant (not ganged), and 4/0 cables and 250 A breakers speced for reasonable short cables.

    It IS possible that the SW+ inverters behave better when one inverter's phase drops out, causing the other inverter to also drop. It would be surprising to me that the SW and SW+ Series-stacked inverter configurations did not both do this. This would seem to alwyas go along with Series stacking.

    Realize that the subject inverters for this Thread are SW. The only docs we have here apply to SW Plus series inverters.

    If you doubt what these docs show, I could try to scan and post.

    Was unable to read the AC wiring diagram in the post just above. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #52
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    The installation manual that came with the series stacking cable shows both configurations as acceptable. When I purchased the system the battery bank was wired thru 2 disconnects with an individual feed to each inverter. I rewired it when I changed the battery bank thru a single disconnect and jumpered as per the other method shown in the manual............John
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #53
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    OK, Thanks John for the added detail.

    A neighbor's SW Series stacked 5548s are wired with separate cables to each inverter and separate disconnects. Learn something new every week or two. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #54
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    The SW/SW+ series inverters were always somewhat unique in that they don't have a master/slave configuration when stacked. That means the chargers operate completely independently of one another. That's why I wanted to make sure John has them wired with the single disconnect, as has always been recommended by professional installers of those systems for split phase stacking. We bought our first stacked pair of SW Plus 4024's from an installer/dealer that has been servicing and installing them since Tim Economu designed and built the first DR inverter at Trace over 20 years ago. They knew all the "tricks" for installing and tweaking them and helped me a few times get them set up properly.

    The only thing that was different about our stacked system was that we had a Trace T240 balancing transformer on the output of the inverters. That was also recommended by the same installer we bought them from. I don't know how good John's leg balancing is, but maybe that could be an issue?

    With our new XW Power System we also have balancing transformer on the distribution panel - an Outback PSX-240. I never really tried the SW's without it. But I have experimented with the XW with and without. There's a world of difference in how well the inverter performs when pushing it to its limits with the transformer vs without.
    --
    Chris
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #55
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Chris,

    Not wanting to get into the Angels and Pins discussion ...

    But you mentioned the reason to use only one disconnect was to elinimate the chance having only one inverter operating with split-phase loads (as I read what you posted). BUT, there is absolutely no reference to using a single disconnect in the SW Plus documentiation here. And, the info regarding Series stacking these inverters and the Xantrex "kits" for such stacking have; two 250 A DC breakers, and individual 4/0 lugged cables for connecting the inverter DC + terminals, and individual cables for the DC -- terminals to the DC -- BusBar, AND NO jumpers. That is what I have seen in use. Personally, I have no reason to believe that Xantrex has gotten this wrong, and have no hotshot installer telling me that this is wrong.

    There is no disagreement that the SW family has independant Chargers, but this does not recommend against separate battery to inverter cables and breakers, IMHO. When using these 5548s stacked, one can supply 120 VAC into the AC-in terminals and use one inverter to charge the batts ... NO "Stacking Error" results ... definitely independant.

    Perhaps, I should go out and Fault-Off one inverter, and see if the other inverter is shut down, due to a Stacking-Error (?).

    I do NOT need to be "right" about this, life is too short.
    It is nice that you have Experts available for good advice. Larger systems can demonstrate dramatic failures!

    EDIT: Here is a link to that large --12.4 Mb pdf. The last two pages show the dual breakers and cableing, FWIF:

    http://www.energyalternatives.ca/mmAEONLINE/Others/Wiring%20Diagrams%20(976-0076-01-01%20Rev%20A).pdf.

    Sometimes links to X and S docs do not work, and some break after a time, but this was the first hit with that Doc # on Google.
    All The Best, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #56
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    I don't think leg balancing is part of my issue. I removed all loads the other day and tested the system and still had the surge/hunt issue while charging was the only load. My leg balancing is pretty good, however I do like the idea of installing a transformer to make sure.

    I have thought about replacing the inverters with an Outback Radian but the SWs seem to do everything else very well....John
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #57
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    Vic wrote: »
    But you mentioned the reason to use only one disconnect was to elinimate the chance having only one inverter operating with split-phase loads (as I read what you posted). BUT, there is absolutely no reference to using a single disconnect in the SW Plus documentiation here.

    There is here, but my manuals came with the inverters and it says on them 976-0043-01-02 Rev B. I don't know what year that is for the print of the manuals. But the wiring diagram in my installation manual for the ISC-S shows optional dual DC disconnects (optional with long DCCB) and it shows jumpers between the inverters to prevent them from being shut down independently.

    However the wiring diagram for use with the ISC-P parallel cable does show omission of the jumpers with dual DC disconnects.
    --
    Chris
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #58
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    Hi John,

    Well the Radian, as I understand it, uses boards from the 48 V 3600 Watt inverters. This design is about a decade old design, if not older. Not very new technology, and there are opinions rattleing around that the OB inverters do not have stunning Power Factor Correction -- I have no direct experience with them.

    The SW and SW + es are very capable, solid inverters.

    As much as I HATE Schneider (primarliy for their apparent total disregard for their customers after the sale), if you were thinking of "upgrading" inverters, the XW may well be the best available, especially for off-grid use.

    OK Chris, i have the same manuals that you referenced by number. They are copyright 2003. NONE of the diagrams in those manuals for dual inverters of any configuration show ONLY one breaker for an inverter pair. There was one reference to using jumpers between a pair of inverters when there are voltage sensing errors between the two inverters. But none of the diagarms in the SW+ manuals, in the ISC-S manual or in the Wiring Diagram/Menu Map Addendum, that I linked to above, show ANY dual inverter config with a single Disconnect (breaker), or any jumpers twix the inverters.

    In the ISC-S manual page 1-6, notes that one of two things the stacking cable does is to allow one inverter detecting an error condition to command the other inverter shut-down. It does not say that this occurrs when one inverter trips its breaker... would hope that it does. But when one of these 250 A DC breakers trip, it is probable that at least one inverter is toast.

    That is all that we have here.

    Second point, John; We use several gensets on the stacked systems here. Have used a Honda EU6500isa set for 240 VAC output. This worked fine running both chargers in Bulk (could not run chargers at their max charge current), but when Vabs was reached one leg of the Honda would get yanked out of voltage regulation, and that inverter would drop the AC in ... and start the qualification process again. Then a bit later the other inverter would yank the genset out of voltage regulation. This could generally corrected by dialing each inverter's charger AC current setting down to use only about half of the gensets max output.

    More recently, have just switched the Honda's output to 120 VAC, and run only one inverter's charger at its maximum, and this seems to work fine. Neither the Diesel, nor the LPG Kohler gensets seem to pay the slightest attention to the variable loads that the stacked SW+ es place on them when in Bulk or in Absorb. Realize that your SWs are not identical to the pluses. As mentioned before, the neighbor with the Honda 11/10 KW genset has not had any problems with hunding/surging with his series stackes SWs with chargers runnng full tilt.

    If you could possibly borrow a largish portable genset from a neighbor, dealer, or perhaps rent a genset that you would consider owning if it performed well, you might learn a bit more.

    Have even used a Honda EU3000is (120 VAC) genset into one of the inverters to charge the batts a couple of times without problems.

    And, there is always a LARGE DC charger with your present genset as a possible option. We have a HomeBrewed Transformer/Rectifier/Capacitor bank DC power supply that feeds an Outback MX-60 MPPT CC. This setup works fine, although the PF is not the best, but the Honda seems to deliver enough power to get about the current that trransformer is rated for. This DC charger is usually run from the EU3000.

    This is about it for me. Wish you the best of luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #59
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.
    Vic wrote: »
    As much as I HATE Schneider (primarliy for their apparent total disregard for their customers after the sale), if you were thinking of "upgrading" inverters, the XW may well be the best available, especially for off-grid use.

    We looked at an operating GS8048 Radian system before deciding on the XW. While some parts of it might be loosely based on the FX-series platform, there are no parts that interchange. The GS8048 has two completely independent 120/240V 4 kVA modules that operate in parallel. Not even close to a FX-series the way it looked to me.

    We are very happy with our XW. And Schneider has been nothing short of excellent for me in the tech support department. Mike in tech support even sent me the engineering drawing for the ISC-S cable and pinout so I could build one, being you can't buy them anymore. While there might be some people who like to complain about something "just because", and those are the stories that make the rounds, it has not been my experience that Schneider has total disregard for their customers after the sale.
    --
    Chris
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  • John Sullivan
    John Sullivan Registered Users Posts: 17 ✭
    #60
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    After fooling with the charger and AC in settings it seems that the best settings I've found to minimize the surging/hunting issue are as follows. AC in 33 amps, max charger amps 25. These settings seem to be the most stable across the complete charge cycle. They are well below the max generator capability and the SW charge capability.

    Still open to suggestions if anyone comes across new info regarding this issue.......John
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #61
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    Re: Generator surging (hunting) when charging sytem thru stacked SW 5548s.

    I caught our XW doing this this morning. I thought of you immediately and went and grabbed the camera to document it.

    [video=youtube_share;L4XU9kSvElo]http://youtu.be/L4XU9kSvElo[/video]

    I was not able to determine what was doing it. It looks like it was related to the load because the load amps were varying, which causes the charger to "hunt" as the XW adjusts the charger output to keep the generator loaded even. My bride was cooking breakfast on her induction range top and the only thing I can think of is that at the low heat setting she was using to cook with, the range varies the power to the Litz Coil for the induction "burner", and that's what was causing the fluctuation. But I'm not sure on that - I hadn't had my morning coffee yet so I don't even know if my brain was running or not :D
    --
    Chris
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