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Forum Index : Other Stuff : Genset Voltage
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| FNQPaul Newbie  Joined: 16/04/2013 Location: AustraliaPosts: 5 |
G'day all, I'm only new to this site and already have enjoyed some great info. I've searched this site but can't find what I'm after so I'll put it out there. We run a RAPS using solar, wind and generator backup on our 670AH battery bank. We invert 24v to 240v using an Outback Inv/ Charger. Lately when starting the Genset, the Outback has not been recognising the 'AC in' for some time, at which point it calls it up and starts charging. I've checked the Genset voltage and it's reading around 215v (+/- 5v) and about 52Hz. If I increase revs to closer to 230v this tends to increase the frequency also, which I'm worried about. The Outback parameters are: 208v minimum - 270v max What could the problem be?? It's been running fine for several years until now. Is the Genset tired? Is the capacitor stuffed? Once the inverter has switched to the Genset (sometimes it takes up to 15mins) it settles to around 240v and all is OK. Any thoughts?? Oh, one more thing... when inspecting and topping up the batteries last week I noticed a blue paste substance forming around several of the positive terminals. I'll clean up all the terminals but should I be worried? They're approaching 5 years old. Cheers, Paul. |
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| MOBI Guru  Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Hi Paul, My system is similar to yours. I don't have the genny hooked up yet. I did have a diesel 8kva generator that was brushless technology and I thought the capacitor had gone kaput and putting on a slightly bigger one made things work ok...but...it was a Scorpion brand and turned out the windings had an internal short circuit and the only way I could test it was to change all the generator parts bit by bit. Fortunately I had a "tame" supplier of generator parts. In my case, the short was in the stator windings. The repair job was much more than a new unit. There is usually a bridge rectifier on the rotor windings that could be playing up. Anybody got a use for a diesel engine with no genny? I meant to add that when mine went bung, the generator became quite noisy (electrically) and some appliances didn't like running off it. Once it settled down, the voltage came back up to roughly 220 again. David M. |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Have you tried placing a light load on the genset AC to see if the voltage comes up, perhaps a 100 watt light globe, this might help bring the charger on line sooner too. I take it the generator is a brushless type, and it might well be the cap starting to become problematic. Pete. Sometimes it just works |
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| FNQPaul Newbie Joined: 16/04/2013 Location: AustraliaPosts: 5 |
Thanks guys, I tried a light load initially but that was using a bench grinder and the load wouldn't have been much after start-up. I'll get a 100w globe and try that. You both mention "brushless" alternators.. how do I tell? It's a 7kva Honda petrol with a LINZ alternator from Advanced Power. I have also used an arc welder off the genset.. I know they don't like these much so could this have caused or contributed. I've welded many times with it but only now am I having issues. Cheers, Paul |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Hi Paul, The blue growth is sulphuric acid leaking past the seals where the posts go through the battery case and evaporating to a salt on the posts. If the seals are perished its just inconvenience and mess and a bit extra maintenance. If the plates in the battery are expanding from sulphation and deforming the top its a sign that the batteries have had some charging problems for a while. you have to look really close to see it, the positive post will be higher than the negative one. You will have to check the alternator model number on the linz electric website, I think they do both capacitor load and brushes/voltage regulator style in that size. 51.5 rpm is spot on the money for fast idle (unloaded) revs. An AVR alternator will be bang on the rated voltage and the cap loading one will be slightly higher at a fast idle. Same advice as always, look for the simplest and cheapest solution first, might be just a dodgy plug on the generator or some loose connections inside the genset. I think the 208volts - 270volts would be the point where the outback controller would cut power from the alternator, the voltage range for hooking up would be quite a bit narrower than that. I'm confused, no wait... maybe I'm not... |
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| isochronic Guru Joined: 21/01/2012 Location: AustraliaPosts: 689 |
The blue colour also suggests corroding copper eg wiring... might be worth checking it is all solid still |
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| FNQPaul Newbie Joined: 16/04/2013 Location: AustraliaPosts: 5 |
Thanks everyone, 1. The genset likes a heavier load (150watt floodlight) and the inverter clicks over straight away. The alternator is not brushless but I'll soon replace the 40 microfarad capacitor and see how this helps. For now I'll just use the floodlight until the inverter kicks in and then turn it off. 2. I gave the batteries a good clean up on the weekend. most of the positive terminals were crusty and several I had to chip the blu/red crust off. They are Exide batteries with rubber seals over the terminals. I cleaned them all up and filed all the cable ends to give nice clean contacts and tightened everything up. I'll keep an eye on them and see what happens. Yahoo2, you're right with the Outback genset voltage. 230v seems the minimum 'call-up' voltage. Thanks heaps for all the advice everyone. BTW. This week we've had really strong winds up here and the little AirX 400w has been powering 24hrs/ day! Even saw it reach 18amps several times. I'm really noticing it in battery voltage in the morning having been charging most of the night... Go you good thing! :) Paul. |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Im not sure if i would go so far as to call a AirX as a good thing, most times they are a useless thing. With the fact its making useful power for you is a good thing, but not all good things always last long, so mark it on the calendar, because it might be a while before the AirX makes good power again. They really are a useless mill compared to most mills on the market, as they need next to a storm to make useful power, otherwise they just spin their guts out and make nothing useful. Sometimes it just works |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
If it has got brushes, I would be looking at them to see if one may be glazed , worn down, jammed or has a loose or broken spring. I had a Dunlite on a Lombardini diesel that was so loud it sounded like a helicopter was landing in the yard, that thing would chew through a set of brushes in about 20 months. used to keep a spare set and capacitor with the machine 24/7, never breaks down sittin in the shed, does it! 
I prefer them to the capacitor start models, lot less chance of cooking an electric motor. I'm confused, no wait... maybe I'm not... |
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| FNQPaul Newbie Joined: 16/04/2013 Location: AustraliaPosts: 5 |
OK, I bought a new capacitor ($35) and all is well. I had to reduce the RPM to drop it down to 50Hz and it's holding voltage and the Outback picks it up straight away. Pretty happy that it was a cheap solution! You're right 'Downwind' the AirX is mostly just a trickle charger for our system still, it's better than nothing especially at night when the solar does SFA. I bought it 5 years ago and only installed it last year. Should I have gone with a Chinese one? Ideally I'd like a vertical axis turbine but ... $$$. Paul. |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
I would think a Chinese mill would be 10 times more productive than the AirX, although going to a vertical mill would be no better than the AirX, as i would put both in the kinetic art category. Sometimes it just works |
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| Georgen Guru Joined: 13/09/2011 Location: AustraliaPosts: 462 |
May I ask which smaller wind turbine is best to buy these days? And who sells them? George |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
It all depends on what output you want, if we use a AirX as a base example, then i would say any Chinese mill will out perform it. For a good 500w HAWT at a reasonable cost, i dont think you could do much better for output to $$ spent then one of the Chinese (OEM) mills Phill sells, although it is well worth getting Phill to modify the mill for you, and not purchase an out of the box mill. OEM got 95% of the design correct, although the last 5% is very important if you want a well working mill and good power output, which is what Phill has done and perfected to suit the mill. Phill is also Aussie based and very active here on the forum, although of late out of contact due to other commitments. Pete. Sometimes it just works |
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| FNQPaul Newbie Joined: 16/04/2013 Location: AustraliaPosts: 5 |
What is the modification required? Where can I find Phill? P. |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Best to speak to Phill on that or search the forum as he has listed most of them over time. http://www.thebackshed.com/forum/pop_up_profile.asp?PF=217 Sometimes it just works |
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