I'm imagining that Pure sine wave inverters 4,000-6,000 watt are available from ebay for under 75 bucks... What happened to the $ 269,00 price tag of a month ago ? I'm building a back-up for my back-up generator . Was thinking a 5 hp Briggs running at half speed + ,turning a 105 amp Delco 1 wire ,charging a pair of group 31 batteries , powering up a 4-6 k pure sine wave inverter. Should power up a later model gas furnace and a couple of lights on the cheap side. It's got to be cheaper to run than my OLD Homelite 5000 with rope start cast iron 10 hp Briggs engine. Still, I can't believe the price difference in inverters. Any thoughts ?
- Thread starter Roy Suomi
- Start date
Janicholson
Well-known Member
Pure sine wave may be defined by the seller. Furnace electronics are sensitive to that purity, and tailored to Grid electricity. I would want a clean (read quality) inverter. 5hp adjusted to 50% speed will be running with less than 5 hp, so why run it slow? Jim.
MarkB_MI
Well-known Member
- Location
- Motown USA
Hmm. I picked out a '6000 watt pure sine wave inverter' at random from eBay. This particular beauty sells for 26 bucks with free shipping! Here's what the fine print says:
[i:654c4848f0]6000W High Power Inverter: Provides 900 Watts continuous modified sine wave power and 6000 Watts peak power. Converts 12V/24V DC battery power to standard 110V AC.(Please confirm your device is in 900W continuous power).[/i:654c4848f0]
6000 watt pure sine wave inverter
[i:654c4848f0]6000W High Power Inverter: Provides 900 Watts continuous modified sine wave power and 6000 Watts peak power. Converts 12V/24V DC battery power to standard 110V AC.(Please confirm your device is in 900W continuous power).[/i:654c4848f0]
6000 watt pure sine wave inverter
Hey Roy, You ask Any thoughts ?
SURE DO Ive bought and used several true actual Pure Sine Wave Inverters, Alternators and Gensets over many years on Flea Bay, Amazon, Camping World etc etc NEVER SEEN NOR HEARD ANY ACTUAL PSW ANYWHERE NEAR THAT PRICE FOR THAT SIZE
There's lots of hype and downright false advertising going on in those circles. There are much cheaper Modified Sine Wave MSW advertised as Pure Sine and there's lots of surge or short term power ratings advertised out there versus the actual continuous power.
NOTE When a motor starts it may draw 3 to 6 times the current required to run it, and an Inverter or Generator EVEN IF adequately rated only enough for the run load MAY NOT BE ABLE TO START THE MOTOR.
NOTE an engines HP may be rated for such at full RPM so if running at lower RPM ITS NOT PRODUCING THAT HP
NOTE for many typical RV, Marine and Inverter powered loads, DEEP CYCLE batteries are preferred over engine STARTING batteries.
NOTE Each device, Genset, Alternator, Inverter, Engine, Battery in such a configuration HAS HEAT LOSS none are 100% efficient WELL DUH so an Inverter or Genset needs adequate rating and enough capacity WITH LOSSES to be able ESPECIALLY to START a load plus keep it running continuous
Im NOT saying what you propose cant work, IM ONLY SAYING you need adequate rated components and that price sounds too good to be true if it were an actual PSW 6000 Watt Inverter (Yeah Right)
If you figure the combined price of Batteries,,,,,,,Inverter,,,,,,,,Alternator,,,,,,,Engine to turn the alternator,,,,,,,,,PLUS all the complexity, wiring, INefficiencies,,,,,,,and build,,,, MAYBE A BIG ENOUGH GENSET MAY BE THE BETTER ROUTE Im ONLY saying, its your choice, what you propose WILL WORK if allllllll the components are adequate rated
John T Live in the RV in Dunellon Florida
SURE DO Ive bought and used several true actual Pure Sine Wave Inverters, Alternators and Gensets over many years on Flea Bay, Amazon, Camping World etc etc NEVER SEEN NOR HEARD ANY ACTUAL PSW ANYWHERE NEAR THAT PRICE FOR THAT SIZE
There's lots of hype and downright false advertising going on in those circles. There are much cheaper Modified Sine Wave MSW advertised as Pure Sine and there's lots of surge or short term power ratings advertised out there versus the actual continuous power.
NOTE When a motor starts it may draw 3 to 6 times the current required to run it, and an Inverter or Generator EVEN IF adequately rated only enough for the run load MAY NOT BE ABLE TO START THE MOTOR.
NOTE an engines HP may be rated for such at full RPM so if running at lower RPM ITS NOT PRODUCING THAT HP
NOTE for many typical RV, Marine and Inverter powered loads, DEEP CYCLE batteries are preferred over engine STARTING batteries.
NOTE Each device, Genset, Alternator, Inverter, Engine, Battery in such a configuration HAS HEAT LOSS none are 100% efficient WELL DUH so an Inverter or Genset needs adequate rating and enough capacity WITH LOSSES to be able ESPECIALLY to START a load plus keep it running continuous
Im NOT saying what you propose cant work, IM ONLY SAYING you need adequate rated components and that price sounds too good to be true if it were an actual PSW 6000 Watt Inverter (Yeah Right)
If you figure the combined price of Batteries,,,,,,,Inverter,,,,,,,,Alternator,,,,,,,Engine to turn the alternator,,,,,,,,,PLUS all the complexity, wiring, INefficiencies,,,,,,,and build,,,, MAYBE A BIG ENOUGH GENSET MAY BE THE BETTER ROUTE Im ONLY saying, its your choice, what you propose WILL WORK if allllllll the components are adequate rated
John T Live in the RV in Dunellon Florida
Good thing I posted this as you were right to question the continuous output wattage. It was very low as their advertisement stated a higher wattage. And yet the text below the ad did say a much lower continuous output. Oh, the reason to run the Briggs at a lower rpm was because of a 6 engine pulley and a 3.5 alternator pulley. It didn't need to run WOT for noise concealment and alternator efficiency. I also made up a quiet muffler 4 times the size of OEM and very quiet, unlike my neighbor's whole house unit. Thanks, R.S.
MarkB_MI
Well-known Member
- Location
- Motown USA
> Can any alternator be pushed to its max output for any extended period?
> How long can a 105 amp Delco 1 wire alternator last if pushed to 105 amps?
Well, George, as you might guess there's an SAE spec that covers alternators: J56. But I don't intend to pay 61 bucks to find out exactly what it says. What I have found is it requires the alternator's idle output to be tested at 13.5 volts and 1500 alternator shaft rpm, and the high speed rating at 6000 rpm. If there's any requirement for duty cycle or endurance, I haven't found it.
That said, if you look at the output terminal of a typical alternator, it's pretty clear it's not meant to provide 100 amps of continuous current. The terminal and wire gauge don't seem to be anywhere near big enough for that. My 3/4 ton pickup has a 220 amp alternator and I'm pretty sure it doesn't have a AWG 2/0 wire running up to it. My guess is you could draw 50 or 60 amps continuously from a 100 amp alternator without blowing a diode or burning up the stator.
Even if you can run an automotive alternator indefinitely at rated output, 105 amps at 13.5 volts is only about 1400 watts. When you can buy a very quiet, efficient and lightweight 2200 watt inverter generator for around a thousand bucks, it doesn't seem very attractive to me to run an automotive alternator off a noisy and inefficient B&S engine to only get 1400 watts. Back in the day, when generators were expensive, a lot of folks would cobble up homemade gensets using car alternators with the voltage regulator disabled. But I don't really see the point in it now, other than as an experiment.
> How long can a 105 amp Delco 1 wire alternator last if pushed to 105 amps?
Well, George, as you might guess there's an SAE spec that covers alternators: J56. But I don't intend to pay 61 bucks to find out exactly what it says. What I have found is it requires the alternator's idle output to be tested at 13.5 volts and 1500 alternator shaft rpm, and the high speed rating at 6000 rpm. If there's any requirement for duty cycle or endurance, I haven't found it.
That said, if you look at the output terminal of a typical alternator, it's pretty clear it's not meant to provide 100 amps of continuous current. The terminal and wire gauge don't seem to be anywhere near big enough for that. My 3/4 ton pickup has a 220 amp alternator and I'm pretty sure it doesn't have a AWG 2/0 wire running up to it. My guess is you could draw 50 or 60 amps continuously from a 100 amp alternator without blowing a diode or burning up the stator.
Even if you can run an automotive alternator indefinitely at rated output, 105 amps at 13.5 volts is only about 1400 watts. When you can buy a very quiet, efficient and lightweight 2200 watt inverter generator for around a thousand bucks, it doesn't seem very attractive to me to run an automotive alternator off a noisy and inefficient B&S engine to only get 1400 watts. Back in the day, when generators were expensive, a lot of folks would cobble up homemade gensets using car alternators with the voltage regulator disabled. But I don't really see the point in it now, other than as an experiment.
Mornin Roy, thanks for the feedback
Oh, the reason to run the Briggs at a lower rpm was because of a 6 engine pulley and a 3.5 alternator pulley. It didn't need to run WOT for noise concealment and alternator efficiency.
Thats a good plan and so long as the required HP (A function of Torque X RPM) is still being produced that sounds great
I also made up a quiet muffler 4 times the size of OEM and very quiet, unlike my neighbor's whole house unit. Thanks, R.S.
Your friends and neighbors will appreciate that Im sure, good job
John T Still near Dunnellon Florida closer to Ocala later
Oh, the reason to run the Briggs at a lower rpm was because of a 6 engine pulley and a 3.5 alternator pulley. It didn't need to run WOT for noise concealment and alternator efficiency.
Thats a good plan and so long as the required HP (A function of Torque X RPM) is still being produced that sounds great
I also made up a quiet muffler 4 times the size of OEM and very quiet, unlike my neighbor's whole house unit. Thanks, R.S.
Your friends and neighbors will appreciate that Im sure, good job
John T Still near Dunnellon Florida closer to Ocala later
I've got a backup for my backup generator. Why run a gas engine 24 hours a day? Mounted in my van, includes solar, design for on the road. It's sized to take care of my electrical needs when I don't need much with a few short spurts of a furnace, fridge etc, which is most of the time.
Mark said: back in the day a lot of folks cobbled up their own generators with an automotive alternator. Guilty! Built one twenty-five years ago and it sits in the corner of the garage and never gets used. Way noisier than a store-bought unit. Of course, I did use a 14 HP Tecumseh out of an old asparagus picker so there is that. It was all I could get my hands on at the time.
My friend bought a cheapy HF Raptor generator and a cheap battery charger and invertor. Then he poured a small slab and built a doghouse (for lack of a better term) around it. It houses the generator, charger, invertor, and four six-volt batteries and is enough to run his refrigerator and his furnace blower motor for several hours before needing to recharge. His furnace is pretty old and has no problem running on modified sine wave. I don't doubt the newer stuff might have a problem. I have a square wave invertor and have only had two or three things that wouldn't power up.
The term pure sine wave invertor is somewhat confusing in that most of what is sold as "pure" sine wave is actually still a stepped wave form. It's just that the increments are small enough that it's not an issue for your more delicate electronics. I will be upgrading to "pure" sine wave whole house invertor one of these days, however the one I'm looking at is 2400w (stackable) and runs about two grand. For what you're doing I would do as my friend did.
One more thing, John mentioned not using automotive or marine deep cycle batteries, I can't stress how important that is! Those batteries will not hold up to repeated charge/discharge cycles like a good old fashioned deep cycle flooded lead acid 6v golf cart battery. I know it doesn't make sense, they're designed to run trolling motors, but my experience was that after 10 or so discharge cycles they act more like a capacitor than a battery. Perhaps I discharged them TOO much, but it is what it is and that was my experience.
For what you're trying to do, again, I think you'd be happy with a set up like my friend built. The only thing I would do is add a cheap charge controller and 4 or 5 hundred watts of solar panels. Keep the batteries charged all the time when not in use without a battery maintainer.
Just my two cents.
JD
My friend bought a cheapy HF Raptor generator and a cheap battery charger and invertor. Then he poured a small slab and built a doghouse (for lack of a better term) around it. It houses the generator, charger, invertor, and four six-volt batteries and is enough to run his refrigerator and his furnace blower motor for several hours before needing to recharge. His furnace is pretty old and has no problem running on modified sine wave. I don't doubt the newer stuff might have a problem. I have a square wave invertor and have only had two or three things that wouldn't power up.
The term pure sine wave invertor is somewhat confusing in that most of what is sold as "pure" sine wave is actually still a stepped wave form. It's just that the increments are small enough that it's not an issue for your more delicate electronics. I will be upgrading to "pure" sine wave whole house invertor one of these days, however the one I'm looking at is 2400w (stackable) and runs about two grand. For what you're doing I would do as my friend did.
One more thing, John mentioned not using automotive or marine deep cycle batteries, I can't stress how important that is! Those batteries will not hold up to repeated charge/discharge cycles like a good old fashioned deep cycle flooded lead acid 6v golf cart battery. I know it doesn't make sense, they're designed to run trolling motors, but my experience was that after 10 or so discharge cycles they act more like a capacitor than a battery. Perhaps I discharged them TOO much, but it is what it is and that was my experience.
For what you're trying to do, again, I think you'd be happy with a set up like my friend built. The only thing I would do is add a cheap charge controller and 4 or 5 hundred watts of solar panels. Keep the batteries charged all the time when not in use without a battery maintainer.
Just my two cents.
JD
MarkB_MI
Well-known Member
- Location
- Motown USA
> There is no such thing as a pure sine wave inverter.
For that matter, there is no such thing as a pure sine wave generator. There are always additional harmonics, even in grid power. So-called 'pure' sine wave inverters boast less than five percent total harmonic distortion, which is probably good enough.
For that matter, there is no such thing as a pure sine wave generator. There are always additional harmonics, even in grid power. So-called 'pure' sine wave inverters boast less than five percent total harmonic distortion, which is probably good enough.
Tramway Guy
Well-known Member
Cant you add a reactor to smooth out the sine wave? That works on the output of VFDs.
MarkB_MI
Well-known Member
- Location
- Motown USA
> Cant you add a reactor to smooth out the sine wave? That works on the output of VFDs.
Filtering reduces, but does not eliminate, harmonics.
Filtering reduces, but does not eliminate, harmonics.
That could help smooth and even out the wave. The quality of the waveform of so called PSW Inverters varies with price in my experience and observation. The cheap Modified Sine wave MSW Inverters are sometimes hyped and marketed as PSW WHICH THEY ARE NOT !!!!!!!!!! Ive installed many in RV's over the years and Magna, Xantrex, Victron and Renogy have performed well.
John T 50 year RV owner
John T 50 year RV owner
Yes proper sized capacitors can help and its been too long ago but I used to know how to design Butterworth Filters consisting of Inductors and Capacitors to smooth out irregular or pulsing waveforms. Electronics is NOT my cup o tea however so dont bet your life on this lol
John T
John T
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy