inverter-generator frequency issue

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rama
rama Solar Expert Posts: 36 ✭
in Off Grid Solar & Battery Systems #1
Hi, does anyone have experience with, or perhaps could point out possible cause of the problem, in this scenario:

my friend has a cabin in remote area without utility and he's got this psw inverter-generator 5kva and recently purchased another inverter-charger 8kva on eBay. The inverter-generator provides the ac charging source for the inverter-charger unit. from what I understand the loads he's running include stereo, tv, dvd player, and a 1.8kw water heater (from what I know). as there's no utility, he powers his loads through battery mode. he started to notice a few times that the output frequency from the inverter would slowly increase from 50hz to near 70hz (which i guess is the limit of the inverter) and shut down the loads. the whole process takes anywhere from 30 min to an hour.

i don't have detail info on the loads yet but i've advised that perhaps he could unplug the ac-input on the inverter first and test this without generator and see what the problem might be. he said the inverter-generator works fine on its own and he's not had any problem with it before. local uses 230v/50hz.

any clue? :confused:
thanks.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
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    Re: inverter-generator frequency issue

    Locate the sales slip and make a warranty claim ?

    If the genset inverter is drifting that much, something is very wrong. Possibly overheating? Scrap of paper sucked in blocking the fan ?

    Any idea what the "power factor" spec of the charger is ? Maybe it's overloaded but not so much to trip the breaker ?
    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 ,

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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
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    Re: inverter-generator frequency issue

    Some details as to make and model of both the genset and inverter might help.

    Just to be clear, if the generator is running and feeding AC to the inverter, then everything runs off the gen. If the gen is off and disconnected then everything is running off the inverter. It's important to know in which of these states the frequency drift is occurring.
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  • rama
    rama Solar Expert Posts: 36 ✭
    #4
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    Re: inverter-generator frequency issue

    Thanks for responding -
    I don't have the genset's spec here (will try to get later) but he bought the inverter off ebay - http://www.ebay.com/itm/8000W-Solar-Pure-Sine-Wave-Inverter-48V-220V-240V-/150512501066?pt=AU_Solar&hash=item230b3e814a

    It's got a 60amp AC battery charger.

    He said the problem occurred most of the time under battery mode and the generator is turned off (but stayed connected) to the inverter, though problem do still occur when the genset's running. Can a generator that's not running cause this to inverter output? Anyway to isolate the cause I asked him to fully disconnect the genset, and see if the inverter does this on battery. Hope to have some updates later... it's just I've never seen any inverter doing such crazy output on its own.

    Strange thing is he said before buying the inverter, he didn't notice this problem with the genset when it was used to power a UPS unit for PC.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
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    Re: inverter-generator frequency issue

    Initially it looks like a case of "you get what you pay for". :roll:

    8kW 48 VDC inverter with 16kW surge, an extremely wide ranging AC input, very high capacity charger, and a built-in PV controller - all for $1,500.

    Meanwhile Xantrax has the audacity to charge over $3,000 for theirs and it's only 6kW and doesn't have a built-in PV controller. On the other hand it actually works. :roll:
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