Unconfigured Ad Widget

Collapse

Announcement

Collapse
No announcement yet.

Suitable generator

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Suitable generator

    I want to buy a generator just wondering which would best suit my needs
    are these small inverter types suitable for pumps or maybe a diesel gen off ebay and what size would do the job my pump is an ebay Qb 70 about 60 litres a minute.
    sigpic

  • #2
    Re: Suitable generator

    Originally posted by Captain_caveman View Post
    I want to buy a generator just wondering which would best suit my needs
    are these small inverter types suitable for pumps or maybe a diesel gen off ebay and what size would do the job my pump is an ebay Qb 70 about 60 litres a minute.
    What power does your Qb70 draw?
    G

    Comment


    • #3
      Re: Suitable generator

      all it say's on the pump is 240 volt 3.5 amp 3/4 horsepower no wattage rating even though i think i could work it out, not sure on start up wattage which is usually much higher than operating wattage
      sigpic

      Comment


      • #4
        Re: Suitable generator

        Originally posted by Captain_caveman View Post
        all it say's on the pump is 240 volt 3.5 amp 3/4 horsepower no wattage rating even though i think i could work it out, not sure on start up wattage which is usually much higher than operating wattage
        240 volt * 3.5 amps = 840 watts

        Oh by the way I think that induction motors need a full sine wave to work, you just need to make sure that that your genny can produce a full sine wave

        If I am wrong could one of our resident sparkys please correct me, if we have any.

        Thanks
        shiner
        shiner
        Donating Member
        Last edited by shiner; 4 October 2006, 02:19 AM.
        Diagonally parked in a parallel universe

        ppythonsss@yahoo.com.au

        Comment


        • #5
          Re: Suitable generator

          You got it right Shiner, the best way to go may be to get a 10-12hp Honda diesel and attach it to either a 12 or 24v car or truck alternator. Trucks are better as they normally produce about 120amps. Then run it through a pure sine wave inverter. Its more economical that way, quieter and they run excellently on bd. You could use a 1kw inverter or above. I've run things up to 850w on a 350 inverter with a kick start of 750, mind you they struggle and don't last that long. There's plenty of small diesels and second hand inverters around. It also gives you an alternative for powering your house. The most economical inverter I've found is 1500w, as it will kick start a 2 hp motor. Inverters over that are a tad expensive.

          Comment


          • #6
            Re: Suitable generator

            I currently have a 6.5 Hp Chinese Diesel running a small Car alternator through an inverter. I am on the lookout for a 240V head to mate the engine to but in the meantime my on location power requirements can be met with this gen setup and some inverters. Given the rule of thumb with generators, this engine would be good to supply 3000W+ given the right alternator(s). I would suggest you don't go bigger than you need with a gen as they get more expensive, heavier and worst of all, Noiser.

            One thing that a 12V alternator/ inverter system has over a straight generator system ins that at lower loads the engine can be throttled back to use less fuel, make less noise and create less wear. AS long as the inverter has sufficent input current for the load, engine speed is not critical. On a generator, the engine must be at very least withing a narrow speed range so the frequency of the 240V output is correct. For a 50HZ System, the engine needs to spin at 3000RPM if the highly common 2 pole type head is used. Seeing most small engines are rated at 3600 rpm, this is close to the high end of the engines range and will be causeing a fair bit of wear and noise. With a an alternator inverter system, if you are running a low load the engine and alternator may make the current required at only 1500 rpm and the freaquency of the output will still be correct and of course the engine will be a lot less stressed, quiter and more economical.

            I also have a small 750W 2 stroke camping type generator and a 550W Pump. The generator has trouble starting the pump, no doubt due to the crappy power output. Once it is running, it does run it fine. I am thinking of putting a ups between the generator and the pump which does a pure sine wave output to see if that helps things.

            For the load you are wanting to drive, I would reccomend you go straight to a 240V Diesel generator or if you want something much cheaper, a petrol one.
            You can do the car alternator/ diesel engine/ inverter thing like I am currently running but at the higher loads, I think it all starts getting a bit un-economical.

            A 10 Hp diesel engine is going to cost upwards of $500, an inverter of that size in pure sinewave is going to be at least the same. You will also need a 12V battery to stop the alternator popping Rectifer diodes. You can buy a 2Kva Petrol generator that is a much more " all in one " type unit for under $500 off ebay. Carrying round one unit is a lot easier than packing and dragging multiple pieces around. Take it from someone with experience

            You don't say why you want to drive this pump, I am assuming it is for BD production in a location without power. If that is the case, and you are heating by non electrical means, perhaps you may like to consider using a small 1" petrol driven pump. There are available off ebay for around the $200 mark and what I have read of them on the info pop forum, they do a great job with oil.

            An idea I had a while back but have no need to build would be a processor that used co generation from a diesel generator or pump to provide both mixing from either running a pump if it were a generator or pump the oil direct if the unit was a pump itself and in either scenario, make up a heat exchanger to use the exaust to heat the oil up. No reason why you couldn't do the same thing with a small 2-stroke engine on a pump. There are rated at 1Kw Power output so I would believe the actual heat energy could be more than twice that seeing engines are more efficent at making heat than motive power. For the ultimate in efficency, you could start your engine on its first production run with 1L of fuel and from then on you would produce hundreds of times your own fuel requirement!

            There are a few options but the best soloution will depend on a lot of factors you have not mentioned here.
            For instance, would you only use a genny for BD production and therefore short runs or would it be put to other use and have longer run times? Do you need to move a generator around or will it be in a fixed location? Is noise an Issue? Would a generator be used to provide power for a heating element and a pump or do you only need to pump the oil?
            Of course the main factor to all this may well be how much you want or can afford to spend and that in itself may rule a number of options out.
            If you only want to pump oil and you can get a vehicle close to where you need the power, a cheap option may lie with buying an inverter and running it off your car while it idles.

            If I have missed my guess as to what you are wanting or needing, please fill in the blanks and I'll see if there is any other info I can help you with.

            Comment


            • #7
              Re: Suitable generator

              I dont have access to power and would like to run the genny to power my pump for bd production i heat with gas so dont need it for heating just to run the pump i've also noticed on ebay small honda inverter gennys 1000w
              would they be upto the task they say they are pure sine wave i'de like a portable all in one unit
              Captain_caveman
              Senior Member
              Last edited by Captain_caveman; 4 October 2006, 09:57 PM.
              sigpic

              Comment


              • #8
                Re: Suitable generator

                David,
                What brand is your diesel motor, have you had it long, is it easy to start and any comments to quality / price would be appreciated. First hand info is alot better and often hard to get.
                thanks
                bj4408

                Comment


                • #9
                  Re: Suitable generator

                  Hey Bj,

                  I’m not actually sure what brand the engine is. The importer has put his own branding on it. It is a typical Chinese clone that someone in Melbourne was importing but isn’t selling them any more. I have read that there are something like 380 companies in China doing these clone type engines although most seem to be Honda Petrol Knock offs.

                  The thing has got easier to start as it has got more hours on it. I’d say after about the first 12 Hours running time it starts first pull 95% of the time and if it doesn’t, it starts second time for sure. When I got it, the set up of the injection pump was waaay off and the thing was banging and knocking like it had thrown the Rod and probably would have in short order if it hadn’t been seen to. I sent an email to George on the utterpower website and he told me this was a common problem and I just needed to shim the injection pump out a bit. I packed it out about .30 thou and the thing has run like a Rolex ever since.

                  I can’t say much about the price other than I stole it. I was simply watching the thing on ebay at the right time and got it at a once in a lifetime price of $152 + $40 delivery. If I could find any more like that, I would literally take a Dozen. I bought it as a 3” water pump. I was only interested in the engine but the pump just unbolted and I have just bought a used 2.5 KVA Petrol generator for $100 that I intend to use the gen head from to couple to the Diesel engine as was my intention to use the thing as a genny all along. With a bit of luck I can put the pump on the petrol engine. I wouldn’t use a pump that much but would be nice to have just in case of fire or flood in the middle of suburbia
                  Most of the Diesel engines I have seen on ebay since I got mine about 3-4 months ago have been selling from $500 to $900 for the electric start version which mine doesn’t have.

                  I would say I have about 20 hours on the engine now and once I finish this, I’m going out to give it it’s first oil change. I used regular GTX type oil to bed it in, will use some mineral diesel type oil for the next 20 hours or so and then fill it with synthetic. Between that and running it on B100, the engine should last as long as one ever will.

                  I looked the thing over very carefully before I even put oil in it and I was very happy with the apparent build quality. I pulled the exhaust and inlet manifold off and the ports seemed to have been cleaned of all casting flash and dags and there was lube evident on the valve guides which is important when an engine first starts and is bedded in.

                  The last lawn mower I got had a Briggs motor on it and I tore that completely down before it had ever been started and to say the thing was the cheapest, crappiest, poorly engineered POS I have ever seen would be an understatement. I have also torn down other American Built small engines and all I can say is it would take some effort on the part of the Chinese to build something as bad as the "Made in the USA" engines. I haven’t cracked this engine for a look see but so far I am fairly impressed with the way the thing is built and can’t see any inherent problem areas in it. What I have seen would suggest a decent amount of care has gone into building and assembling it.

                  Overall I think the castings of the engine are well made and the machined surfaces appear true and cut with sharp tools for a good finish. There are some plasticky things on the engine like the throttle control knob that broke but I soon welded up a better, stronger one that will last forever. The air box and blower cover are well sealed and the air filter is a quality foam over paper type. There are dipsticks on both sides of the engine along with dual oil fill holes. The fuel tank has a good size filler hole and there is a fine drop in mesh screen in the fuel tank. I replaced the soft fuel lines with some known quality stuff and added a cheap disposable fuel filter. I’ll put a CAV type on it when I can find one at the right price.

                  I have read that the metal fuel lines on some other types of Chinese engines can work harden and crack through vibration so I am intending to order some spares off a known quality manufacturer and put them away as I think it will be pretty much impossible to find anyone here stocking parts for the things although it well could be the Yanmar engine parts they are copied off may fit fine. Considering the price of those engines, importing the chinese parts will probably be far cheaper.

                  One thing about these engines is that they are very noisy and vibrate a lot compared to a petrol engine of the same size. I wouldn’t entertain the idea of using one in any place where noise was a problem. The exhaust is very well silenced but the mechanical clatter that emanates from the thing has to be heard to be believed. It would take an extreme amount of soundproofing and trouble to quite them down although they do use these engines in “ Silent Type” 5KVA units. Looking at my catalogue from a manufacturer of these things, They rate the 5.5HP diesel at 85DBA@ 4 meters, a petrol engine of the same size at 76 DBA and a silent type diesel gen at 77Dba. Obviously the Chinese Definition of “ silent” is as highly subjective as their sizing of clothing :0)

                  I have found the thing to be very economical in fuel consumption. It is rated as having a working time of 2.5 hours on 3L of fuel at full load. Personally I think it would do better than that. Comparative size petrol engines are rated at 2 hours run time from 3.5L of fuel. I have run SVO through the thing when it was up to temp and the engine didn’t change performance or sound in any way. I want to get a another fuel line to modify and attach to the exhaust so I can run the thing on SVO just for fun. A petrol engine of the same output weighs 19KG and the diesel comes in at a considerably more solid … 41Kg!!! The petrol engine is around 160 CC and my diesel of a similar power is 296 CC. Yep, with a diesel you do get a lot more for your money!

                  On thing that I think would make these engines fantastic as generator power plants is the fact the torque curves are almost dead flat. The torque only falls off around 2Nm from 1500Rpm to 3600Rpm. I have had the thing sitting at about 1500 Rpm and dropped a 1.2Kw load on it and it doesn’t drop a rev, you just hear the exhaust note change as the governor opens up. The governor mechanism is simple but seems to work very accurately. On my slightly larger petrol engine, there is a very noticeable dip and recovery with the same load and at higher engine speeds showing it has much less torque and internal momentum.

                  Although I haven’t had the engine long, I have to say I love the thing. For long term or high hour work, I think the diesels would leave a petrol engine for dead in terms of fuel economy and longevity as long as noise wasn’t a great issue.

                  Hope this gives you some answers to your questions.

                  Comment


                  • #10
                    Re: Suitable generator

                    David
                    Thanks for the report, sounds pretty good, at least I now know what to expect for my dollars. A water pump may be on the wish list to water the garden from our dam.
                    bj4408

                    Comment


                    • #11
                      Re: Suitable generator

                      Here are a couple of 10 KVA diesel units I have seen on eBay:
                      Open Diesel Generator - 3 phase 10KVA
                      Silenced 3 phase 10KVA Diesel generator
                      Does anyone have any experience with these or similar units?

                      Tony
                      Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

                      Current Vehicles in stable:
                      '06 Musso Sports 4X4 Manual Crew Cab tray back.
                      '04 Rexton 4X4 Automatic SUV
                      '2014 Toyota Prius (on ULP) - Wife's car

                      Previous Vehicles:
                      '90 Mazda Capella. (2000 - 2003) My first Fatmobile. Converted to fun on veggie oil with a 2 tank setup.
                      '80 Mercedes 300D. 2 tank conversion [Sold]
                      '84 Mercedes 300D. 1 tank, no conversion. Replaced engine with rebuilt OM617A turbodiesel engine. Finally had good power. Engine donor for W123 coupe. (body parted out and carcass sold for scrap.)
                      '85 Mercedes Benz W123 300CD Turbodiesel
                      '99 Mercedes W202 C250 Turbodiesel (my darling Wife's car)[sold]
                      '98 Mercedes W202 C250 Turbodiesel (my car)[sold]
                      '06 Musso Sports Crew Cab well body. [Head gasket blew!]
                      '04 Rexton SUV 2.9L Turbodiesel same as Musso - Our Family car.
                      '06 Musso sports Crew Cab Trayback - My hack (no air cond, no heater).

                      Searching the Biofuels Forum using Google
                      Adding images and/or documents to your posts

                      Comment

                      Working...
                      X