Printable View
I was thinking of buying a generator from Northern but searching around I found this.
Any thoughts? Heard of Duromax?
http://www.ebay.com/itm/DuroMax-8500...item2ebd68ea55
EDIT:
I found it here on Northern for $150 more!
http://www.northerntool.com/shop/tools/product_200399467_200399467?cm_mmc=Google-pla-_-Generators-_-Portable%20Generators-_-166700&ci_sku=166700&ci_gpa=pla&ci_kw={keyword}
EDIT, EDIT:
Total Distortion is 12% no load and 10% with load
It's not a "clean" power source... THD needs to be 6% or less.
Ok.. That's what I needed to know. The one at Northern I've been looking at is 5%Quote:
Originally Posted by zoama585
What does the distortion do?
I can't think of a short way to explain it so open this> pdf and skip to page 18Quote:
Originally Posted by CGCINC
I'll go out on a limb here and say I'm pretty sure I didn't get any of the three pages I read... :)Quote:
Originally Posted by zoama585
I can't believe they sell "dirty" generators to people that have no clue and want to run their household with it, sounds like a recipe for blown up stuff!
Thanks for the link and help
The good thing about Northern Tool's generators is the warranty. It comes with a two year warranty already. You can purchase an extended warranty that gives you an additional years. I also purchased accidental coverage through Northern Tool, so if it falls off my trailer I'm covered. I think it's well worth the coverage since your using it to run a welder.
Check this out...Quote:
Originally Posted by CGCINC
http://www.harborfreight.com/engines...tor-67560.html
I know it is not the same power but the engine looks identical. I thought it looked like the Harbor Freight style. The fuel tank and cap look similar. If you look at the oil sending unit on the side of the engine it looks like the same style and about in the same place.
BTW as far as distortion and a dirty generator goes. They would not be bad on a cheap tv or a fridge that does not have a computer circuit. I always look at what I am running on a generator. Sure I would use a tv but not the new 60" big screen.
My 2 cts on power. In the US our power is 60 cycles which means it cycles + to - 60 times in a second. The sine wave looks like a smooth running roller coaster. The more distortion you have the bumpier the roller coasters ride is. So you can assume the bumpier the ride the rougher it is on the electronics. Some things like motors (drills, power saws, fans) don't really care, but the things with the computer circuits want clean power. They can take some distortion, but you want to keep it pretty stable.
I am building a generator . would this one be ok to run a welder . i need lots a power at shop , got a nice diesel motor to turn this power head . http://www.ebay.com/itm/30KW-ST-Gene...82137174153367 I hate gas generators since so noisy . diesel is the way to go since the power head only turns 1800 rpm instead of 3600 rpm plus a diesel last twice as long before wearing out
to small of a generator
Personally,,I think all this talk about THD and generators is overblown horse puckey,,,if you read on to page 19,,,they identify the main causes of HD as the devices added to the line load not the generator,,,,the generator produces a sine wave and the devices...depending on the type ,,chop the sine wave during use,, causing distortion,,, as a matter of fact I've read articles on the subject that state that THD was not a problem until after 1965 when solid state electronic's and rectifacation was being in general use....in short,,,some of this stuff has to be taken with a grain of salt,,,when it comes to advertising etc....don't want THD,,,don't add a whole bunch of electronic's to the line load....Quote:
Originally Posted by zoama585
Nice to see more between 8kw and 25 KW.... Quite a jump in price... Never could see why a diesel cost so much more.Quote:
Originally Posted by Rodsmachineshop
http://www.northerntool.com/shop/too...atchallpartial
There are other things that come into play on a small gas engine generator, such as load control, ability to maintain a steady rpm and balance. Even though solid state electronics can tolerate the upper "safe" thd range, it can shorten their life.Quote:
Originally Posted by geezer
I guess it comes down to the amount of risk each person is comfortable with in the price range between good and good enough. Maybe our local electrical engineer, Kenwhite will weigh in on the subject.
I agree,, there are other factors and I would like to hear Ken's opinion on the subject,,,,when it comes to gensets I would suggest that anyone getting one,,,look seriously at remote start,,,I have it on mine and it is worth the extra money to get it...also lots of horse power is good as well...so the genset doesn't bog or stall out under load,,,,the one on ebay has 16 hp,,,mine has 15 and it works on my Imig 205 and PA 200 ,,no problem other than being limited to the 30 amp breaker on the genset....my genset runs 256 volts at 63.1 cycles and that surprised me when I got it....at least that's what the readout on it says....Quote:
Originally Posted by zoama585
THD is a measure of harmonic frequency content. A pure sinewave when viewed on a spectrum analyzer is shown as a single frequency, so THD is zero. A squarewave will consist of many sinewave frequencies that are odd multiples of the fundamental frequency at differing amplitudes and this is what the term THD comes from.
If a square-wave drives the primary of a power transformer that is "not" designed for higher frequencies, the transformer can overheat and become damaged very quickly when loaded. The reason for this is that the higher frequencies cause the transformer core to saturate at much lower values (Bmax).
Bmax = (E x 10^8) / (4.44 x N x A x F) (for sine waves)
Bmax= (E x 10^8) / (4 x N x A x F) (for square waves)
Where:
Bmax = Maximum saturation density of a core material in Gauss
E = Primary Voltage
N = Number of primary turns
A = cross sectional area of the core in CM^2
F = the highest frequency of interest in Hz
So you can see a transformer designed for a 60 Hz sinewave is not going to do well (it may fail rather quickly) with the higher frequency components created by a high THD% power source.
This also applies to the generators ability to maintain frequency when loaded and unloaded quickly, etc, etc,...
Oh, and one other thing, generators are really rated in apparant power or volt-amps, not watts. So large reactive loads like motors can draw quite a bit more current than that would be expected if you size the generator based on real power, or watts. A power factor capacitor an help if needed...
The voltage sounds a little high... Is that under load??? Usually high with no load. I think mine on a medium load was pretty close to 240 (245?). Should check the frequency, but don't have anything to check it. But I don't use mine on anything really expensive. Just as a backup. I guess now that I think about it the power we get at out outlets here is just a hair under 125 volts. (250 on both legs) I guess they keep bumping it up over time. Back in the days it used to run about 110.Quote:
Originally Posted by geezer
BTW converted mine over to run on Natural gas also. The kit was pretty simple. I tested it out and it worked great. Haven't had a need for it yet. Natural gas here is way less than half of what gasoline is.
BTW generators are way more expensive to make electric that buying it off the pole. Close to 10x the amount. Depends on fuel that you use and the efficiency of the generator, and I guess the rate you are paying.
Nope,,,256 volts is what it says on the meter,,,I loaded it up the other day to see if it would drop,,,ran a table saw, chopsaw and 1500 watt heater at the same time,,it dropped to 255 volts,,,no discernable change in the engine,,,just hummed along,,,,I have it for portabilty like Sean Murphey does,,,as far as buying off the pole,,,I have quite a few outlets to plug into ,,,, 6 in fact,,one in the basement,,2 in my garage,,2 in the shop,,,and one welder plug on my powerpole that I plug my RV into,,,,seems you can never have enough places to plug into or extension chords long enough...good thing I'm just an amatuer hobby type guy,,,who knows how many I would have if I was a pro and did it for a living...Quote:
Originally Posted by Brian Ski