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| sako243 Member Since: 08 Jul 2014 Location: Wales Posts: 1218   
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After a quick Google (30s) to find out what an AVR generator is I can provide some information that will hopefully help you.
Basically think of an AVR as an Alternator with some intelligence behind it. In really basic terms you can consider an alternator as a mechanical amplifier for electricity. A small current into the field windings uses the mechanical rotation to induce a much larger current in the main windings. The amount of power that is produced is proportional to the amount of current supplied to the field windings. However a classical alternator will then rectify the sinusoidal AC produced by the alternator into DC for the battery (the diode pack). Normally there would be a large capacitor for smoothing but the battery provides this. An AVR does away with the diode pack since you want AC out, the frequency is governed by speed at which the generator spins. What is different is that normally when large loads are drawn off the generator the output voltage will drop as current increases. In order to maintain the output voltage the AVR increases the current to the field coil. Now an inverter type will take the AC produced by the raw generator (I've been referring to generator as the device that converts mechanical rotational energy into electrical). Rectify it to DC and then convert it back into AC usually in solid state electronics these days. The benefit being that the output frequency is independent to the generator variables such as speed. Now in your situation charging electronics I seriously doubt that they're going to have an issue with either type. After all they're taking AC and converting it back into DC... Some electronics (typically older stuff) did use the frequency of the mains to control stuff but these days crystals and microcontrollers are so cheap it is completely pointless. Note there are many types of inverter as well. Sine-wave, quasi sine-wave etc. Typically the more expensive the inverter the more pure the output sine-wave is. The benefit of a cleaner output is lower noise, however, ironically a not insignificant amount of electronics have issues with perfect outputs as they assume and have been tested with noisy / dirty supplies. Note: I know very little about generators but quite a lot of electronics (after all it is my job)... Ed 82 Hotspur Sandringham 6x6 95 Defender 110 300Tdi |
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17th Apr 2017 3:35pm |
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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2527  
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Mike, you may find this an informative read:-
http://www.petepower.co.uk/choosing-generators.html You may find that going to a specialist Generator Hire Company with a list of your requirements and voltage and frequency tolerances will be helpful. Defender 90XS SW Mini Countryman Cooper S Morgan Plus 8 |
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17th Apr 2017 3:37pm |
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| gilarion Member Since: 05 Dec 2013 Location: Wales Posts: 5110 
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I have a Honda Whisper EU2000i Invertor it knocks out 2000 wats, which is great, but what is really great is its really quite, not like some generators, so when camping or caravanning it does not annoy me or anyone else. It is also light to carry and I get on average about one and half hours of use from a litre of fuel. It also charges up my leisure batteries at the same time. I can recommend this generator it’s faultless. For those who like Welsh Mountains and narrow boats have a look at my videos and photos at..
http://www.youtube.com/user/conwy1 |
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17th Apr 2017 3:59pm |
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| mse Member Since: 06 Apr 2008 Location: UK Posts: 5035 
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Thanks
Thats all helpful, thanks - but im sort of still where i was after a few days of research, which is where i think im always going to be...which is probably that and AVR is ok until a point, but a inverter is more guaranteed. I was happy with an AVR generator initially - for the reasons outlined by SAKO, but then i saw a number of sites that said they were no better than normal generators - with discussions into all the things that we might need to power, all having modern micro-processing of some sort or other and all operating on a normal/avr genny for a while and giving up - got me thinking. Also as stated, just like normal inverters, there are loads of different quality ones and unless buying a Honda, there is no way of really knowing how good the inverter is...many say pure sine wave. Where i got more confused, is the majority of the diesel generators (the type i was looking to get 7kva types) tend to only be AVR generators. The also run for much longer 40%+ than petrol generators, meaning operating costs are down - but only if it doesn't fry the electronics in the boiler, pumps, motorhome, computers etc. Hiring is just too expensive and not that flexible - much cheaper to buy and either sell when we have finished or keep and wire in as a house back up supply (which is my preferred idea). All the new ones seem quiet now, well more than the one we have - noise isnt a consideration, fortunately, as to be near it, you will be trespassing - so its just about getting far enough away from us to not drive us insane- those suit case ones are quiet though, as are most of the too expensive honda's Mike |
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17th Apr 2017 4:35pm |
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| miker Member Since: 13 Sep 2015 Location: Surrey Posts: 1763 
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Avr generators are fine when they're big. Big as in 10kva or greater. Then the engine has enough oomph/inertia to not get upset by suddenly changing loads and lots of switch mode power supplies.
For your description I'd go for an inverter set. They will throttle down under low load, and the output will be much more stable than a small avr set. If you just wanted to run a load of power tools and lighting, that's where the avr sets suit well. |
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17th Apr 2017 4:36pm |
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| mse Member Since: 06 Apr 2008 Location: UK Posts: 5035
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Thanks
Yes i wasnt going for a massive AVR one @7kva, given we have a 3.5kva normal genny to run some of the power tools so its back to inverters then 
The inverter one im looking at is 3.4Kva but it says Near pure sine wave Class 1 ac output, with distortion (THD) equal to or below 3% or a 4.Kva 3200w hyundai but its double the price and mentions nothing about the inverter. The honda ones are all 1000 or 2000w and there are just a couple of things that getting to the 3000w range would pay. Who knew generators were so complicated!...ill never knock the national grid again  Mike |
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17th Apr 2017 4:53pm |
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| miker Member Since: 13 Sep 2015 Location: Surrey Posts: 1763
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Your current normal generator could well be an avr model, either that or a simple fixed excitation version.
Fixed excitation under no load will drift up to 250v or more and then be regulated by the load. I'm in a similar position of needing an inverter set, looking at the Hyundai hy3000 range, can be picked up around £400 second hand. Honda EU's are fantastic but expensive. Yamaha make a good inverter generator range, and i believe the senci stuff is meant to be a decent budget option. A friend of mine has a hy3000 that he runs on LPG for his motorhome, and as far as i know is happy with it! |
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17th Apr 2017 4:57pm |
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| miker Member Since: 13 Sep 2015 Location: Surrey Posts: 1763
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What is your scenario? If you're wanting to power a whole house or something you may well also need to look at bonding the neutral to earth (as is done at the entry to a house) and earth spikes. Even if you're powering multiple pieces of equipment so that protective devices operate properly.
Mike |
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17th Apr 2017 5:00pm |
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| Swac3 Member Since: 21 Feb 2015 Location: Aberdeen Posts: 363 |
If its spikes/surges you're concerned about and can easily separate the at risk devices, have you considered Using one of
the power conditioning units, We have them in all our company appartments where I work due to the iffy local power supply and frequent blackouts causing the standby generators to kick in. Theyre not on all the circuits, but supplies for the TV, cable TV box and router are plugged into one. Just a thought 3 Landrovers |
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17th Apr 2017 11:11pm |
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| apt100 Member Since: 05 Mar 2015 Location: Derbyshire Posts: 1547 
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Earthing etc was went through my mind. A quick search found this... http://www.google.co.uk/url?sa=t&rct=j...2-SAGbbCEQ but I recall some other articles as well. One thing to be avoided is back feeding into the network to avoid electrocuting people working on what is supposed to be a dead circuit. |
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17th Apr 2017 11:44pm |
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| mse Member Since: 06 Apr 2008 Location: UK Posts: 5035
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Thanks guys
Our scenario is complicated - from powering a house, through to powering a motorhome. Different needs different loads etc. Mostly while we wait for the shiny new powerlines to be installed. But the bottom line is we need to power just about ever different type of thing at different times, over a protracted period - but all not mega amps and then at somepoint we will have the generator - so it would be nice to employ it as a fall back kit to go with the wind turbine and solar panels. Our Briggs and Statton generator is old (15 years) but probably has 2 hours of use - it definitely is just a bog standard frame generator (albeit it an ok one). Looked at the honda ones (costco do a suitcase one) problem is they dont have the punch for most things, or the run time (i want it to run for around 8 hours - there are some good clarke ones and hyundai ones that im considering and will probably go with...and strongly likely to be an inverter type. I did wonder if a surge protector would work inline to protect the devices Mike |
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18th Apr 2017 7:57pm |
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| NormanD Member Since: 12 Aug 2011 Location: Bristol Posts: 286  
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Try something like this - http://www.justgenerators.co.uk/hyundai-dh...PZ-E_nyvIU NormanD WE191
2015 110 XS Utility 2014 VW Caravelle 180 Executive |
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18th Apr 2017 9:00pm |
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| mse Member Since: 06 Apr 2008 Location: UK Posts: 5035
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thanks
i had looked at this: http://www.ebay.co.uk/itm/322318489540?_tr...EBIDX%3AIT which seems similar and this one was another: http://www.justgenerators.co.uk/hyundai-hy...PaoXtLyuiM i shall have a look round that site - their prices seem ok Mike |
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19th Apr 2017 12:00am |
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| Chopperone Member Since: 13 Nov 2016 Location: Derbyshire Posts: 396
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I am not an expert on this size of generator but over the last 20 + years I have relied on a much bigger size of generator to provide primary power to one part of my business.
My current generator is a 3 phase 80 Kva Perkins based unit. A few years ago I bought a "genuine fake copy Chinese " generator from a company that went into voluntary receivership about a month after I bought it & about 15 mins after the water pump disintegrated & went through the radiator etc. No parts available,no other dealers in Europe & when I contacted the the manufacturer they told me that the generator was a fake & not one of theirs. I fixed it & it never worked properly; it was a constant round of intermittent/ different faults. Moral of the story; bite the bullet & buy a proper generator from a Company where you can get spares/back up & advice. After all you are going to rely on it to provide you with power & then later emergency power. Just my two pence worth Best of luck Guy May your life be like toilet paper ; long & useful. |
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19th Apr 2017 7:00am |
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