Summer Resumes

Well, that arctic blast has moved on and I moved all my potted plants out into the sunshine. It looks like it will be warm enough to spray the dandelions this afternoon.

I took a break to examine the alternator. To my surprise it’s the next smaller size to the one I ordered… Anyway, it’s plenty big enough and half the price asked locally. It wasn’t packed very well. An anchor bolt pulled out in handling. The crate suffered, not the alternator. As a bonus, they also supplied drive belts, so I have spares for the tractor and the alternator. I was going to use longer belts for a vertical drive with a twist, but I may just as well build the trailer to couple directly to the tractor. Then, it will surely drive my welder at full power.

Before fiddling with the alternator it’s time to do serious planting now: corn, beans, squash, grass and a few more trees. I will be busy all week. I just got a call that some grand kids will visit. Even my investments are working hard today. Everything’s finally coming together. My ToDo list will be a lot shorter by June, just replacing my IT-system with a new switch, a smaller but more powerful Beast, and new clients all running GNU/Linux on ARM.

About Robert Pogson

I am a retired teacher in Canada. I taught in the subject areas where I have worked for almost forty years: maths, physics, chemistry and computers. I love hunting, fishing, picking berries and mushrooms, too.
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9 Responses to Summer Resumes

  1. dougman says:

    You never explained, nor provided any sort of load analysis so I was making assumptions.

    But getting back to my earlier statement, kVA = kW at 1.0pf.

  2. dougman wrote, “Since your “power-factor” is 1.0 then KVA=KW”.

    Why would my PF be 1.0? I have an inductive alternator, an inductive welder and inductive induction motors. Only incandescent lightbulbs are resistive and we have fewer of them each year. I would not know where to find one in my house.

  3. dougman says:

    LOL… I am not going to argue with you, but…

    kVA is known as the ‘apparent power’, while kW refers to the actual, or real power. kW is the amount of power capable of doing work, while only a portion of kVA is available to do work. kW is kilowatts, while kVA is kilo Volts Amperes. kVA is equal to kW in DC circuits because the voltage and current are not out of phase (unity). However, in AC circuits, voltage and current may get out of phase. Therefore, kW and kVA will differ depending on the Power Factor, or how much leading or lagging occurs.

    Since your “power-factor” is 1.0 then KVA=KW, but if you lead or lag the current sine-wave by way introducing negative or positive reactance in the circuit, then it does not.

    To amplify further, if you had a inductive or capacitive of proper value, a 30kVA alternator would deliver 24kW and 18kVAR at 0.8 power-factor.

  4. dougman wrote, “30KVA and 30KW is basically the same thing.”

    No, it’s not. Typically these things are spec’ed for 0.8 power factor so it takes 37KVA to deliver 30KW. For a lot of loads and for light loads like mine, it doesn’t matter but to get full power you need to take care of it. The alternator itself is inductive and the welder certainly is but it’s only 14KVA flat out. Single phase induction motors may be 0.6 p.f. but I will have only one or two fractional horsepower to run. The frames for the alternators are built in stages. I wanted the most KVA available for the 184 frame. It’s about the same weight except for windings so the shipping costs would not have been much different.

    I got only half my corn and beans planted today… It’ll take a week to get my garden in at this rate and the weeds are way ahead. Sunflowers are going to be easy. I discarded some sunflower heads in the compost and there are a hundred seedlings growing. I may be able to transplant and gain a few days of growth that way.

  5. dougman says:

    0.745699872 × HP = kW You will only NET ~13KW.

    BTW: 30KVA and 30KW is basically the same thing.

  6. dougman wrote, “What is the KVA rating of your alternator, what are you planning to drive it with?”

    The alternator is rated 30KVA when I wanted 30KW. It’s a tiny difference especially when the thing will mostly be used as a huge flywheel. I was planning to couple it to a 5HP vertical gasoline engine but I’m leaning to couple it to my horizontal diesel 18HP engine on the tractor since the supplier sent me a set of belts that are a bit short for the 90 degree twist. I wasn’t expecting the belts at all since I have a nearby supplier but I mentioned the belt-type on the tractor… So, I’ll be able to slack off the drive-belts of the tractor, drop those belts and hook up the alternator without even removing the belt-guard of the tractor. I can also align the alternator squarely to the frame of a trailer to roll up to the tractor. It’s very convenient. I’m in the midst of planting. This is my corn-beans-squash day. Next week I could give the alternator a spin.

  7. dougman says:

    What is the KVA rating of your alternator, what are you planning to drive it with?

    I just started on my 40×90 garden plot using only a Mantis Tiller, but sometime in the next 12-months I am going to get a BCS tiller or a tiller for my tractor.

  8. DrLoser wrote, “Quality purchase, Robert.”

    It is a fine machine. There’s plenty of room between its capacity and my needs.

  9. Dr Loser says:

    I took a break to examine the alternator. To my surprise it’s the next smaller size to the one I ordered… Anyway, it’s plenty big enough and half the price asked locally. It wasn’t packed very well. An anchor bolt pulled out in handling. The crate suffered, not the alternator.

    Quality purchase, Robert.

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