clean power generator questions

[rhett]

How does one determine if they have a "clean power" generator?

I ask because, Mark @ Everlast and their website state some of their Inverter machines would be suitable for use with a "clean power" generator. My needs are for field use and remote locations without Grid-Power.

Mark, if you read this, I have a TroyBuilt 5550w continuous/8500w surge generator and would like to use a PowerArc 160 or a PowerArc 200. 1/8" rods are what I will burn for most every project. My genset runs my Lincoln WeldPac 155 OK, but 6010 and 7018 weldments are preferred. I would not want to buy an Inverter machine and only ruin it from not asking the question.

Thanks
Rhett

 

[jdonovan]

Take a look at your generators manual.

If it is a sine wave generator, then it should be clean.

If its a square ware generator then its dirty.

A modified sine, or stepped square is 'less clean'.

 

[Haywire]

I looked it up and they don't outwardly claim clean power, but I couldn't see an owner's manual without a serial number.

Ian

Edit... They have 2 different models of 6k troybilt at the lowes site. One says "automatic voltage regulation - no" and the other says "yes". Both are $700 gensets.

 

[Redneck in training]

Clean power has no harmonic frequencies present. It is pure sine wave. For transformer devices (such as welders) it is important that the wave is symmetrical. If it is asymmetrical there will be partially DC current flowing trough the transformer winding possibly burning it. In example there are special dimmers for low voltage lights.
I don't have experience with inverters but my guess is that those care less about quality of power.

 

[jdonovan]

found the manual as a link from here

Nothing in the manual about waveform on the alternator....

BUT usually generators that are sine, or modified sine wave advertise as such as they are a bit more costly to make.

There are some larger 10k troybilt's I've seen that do say they are pure sine wave generators.

 

[rhett]

Thanks everyone for the help,

Below is all I can extract from the manuals available. It is an older model before Sine wave became a selling point, maybe that is why it is not listed in the specs.

The generator is an engine driven, revolving field, alternating current (AC) generator.

I have powered several desktop computers and TV's, no issues noticed. Also, some searching said generators with brushes are Sine wave, it has a Rectifier/Brush Assy. Then again on other forums, some say yes and some say no.

Dang, is putting it on an oscilloscope my only option? A pita, I do not have an oscilloscope, which means a full day going to the big city just to find out.

Thanks
Rhett

 

[Haywire]

You might try calling or emailing troybilt tech support, if there is such a thing.

Ian

 

[Mark @ Everlast]

Rhett,
Most everything said is indeed correct. We do have a little tolerance for low hz because we are safe between 50 and 60 hz. But the sine wave shouldn't look like someone drew it with Parkinson's (my sympathies to anyone who suffers from this terrible disease).

I am NOT one of the electronics experts in the company, but I do know there are "conditioners" that can be bought for some of the better units to clean up the power to acceptable standards. With that said, we have some guys running the products on gensets from the 70's. We warn them though...

 

[wrooster]

All direct-coupled generators produce sine wave output. That is, generators which consist solely of an engine mechanically connected an 120vac/240Vac alternator produce sine wave output -- equivalent to what the utility company provides. Note that with a direct-coupled generator the engine RPM has a linear effect on both alternator output voltage and frequency; the engine must run at a constant RPM (typically 3600RPM or 1800RPM, for 2 or 4 pole alternators, respectively)

Which brings us to inverter-generators, which operate somewhat differently. In an inverter-generator the engine drives an intermediate voltage alternator (typically 12 or 24Vac), and in turn that output is rectified to DC. Subsequently, that DC voltage is used as input to a waveform generation circuit -- which is basically an inverter. Depending on the complexity/cost of the waveform generation circuit, the resultant inverter output can be a squarewave, simple stairstep, modified stairstep, or a true sinewave. The primary advantage of the inverter-generator topology is that it decouples the engine RPM from the output voltage and frequency; only the engine output power is relevant. For low load applications, this means the engine can be run slower, which translates to lower noise and lower fuel consumption. The downside is that dynamic response of inverter-generators is worse than direct-coupled generators, as in an inverter-generator there is less mechanical inertia to counteract high inrush current situations (like starting motors on compressors or pumps).

Summary -- if your generator is a direct-coupled type, you are getting a sine wave out of it.

Wrooster

 

[rhett]

.....
Summary -- if your generator is a direct-coupled type, you are getting a sine wave out of it.

Wrooster

Wrooster, Thank You so much for your detailed descriptive Help and saving me so much time and money! My generator is a direct-coupled type, so it looks like one of them there light, High Tech machines is on my list to be ordered the first of the month. Kinda waiting for test and performance results of the units they now have in stock.

Again, Thanks for all the great Help,
Rhett

 

[Mark @ Everlast]

Rhett,
It can generate a sine wave, but there can be noise on the line that shouldn't be there. The power company sine wave isn't 100% clean either. A good honda genset will generate a cleaner sine wave. Its not as much about the sine wave, but the noise found in the sine wave indicated by bumps, spikes within the wave. Some noise is tolerable, but huge, consistent spikes can cause an issue.

 

[955Lincoln]

There is very good information in this thread but let me throw a wrench into the mix. While it is true that a direct coupled generator produces a sinewave it still needs to be filtered for harmonics like one poster mentioned with chokes, caps, and inductors. For the most part you get what you pay for with generators.

I have a 60's military generator that is loaded with filtering components and the waveform is better than my house power. I also have a cheepo Harbor Freight generator and the waveform looks like it was drawn with an Etch-O-Sketch (A little more politically correct ) In the middle I have a quality Kubota (Yamaha) generator with a fair waveform.

I don't know know just how perfect Everlast needs to be but....there ya go.

The pricy inverter generators have a very good true sinewave but as Wrooster mentioned they are slower to respond with heavy loads and I don't know if this would be an issue for your welder.

 

[wrooster]

Rhett,
It can generate a sine wave, but there can be noise on the line that shouldn't be there. The power company sine wave isn't 100% clean either. A good honda genset will generate a cleaner sine wave. Its not as much about the sine wave, but the noise found in the sine wave indicated by bumps, spikes within the wave. Some noise is tolerable, but huge, consistent spikes can cause an issue.

It's a bit more complicated than that. The interaction of the load with the power source plays a large part in what you see on the line. It is never sufficient to look at just the unloaded output of the generator; nor is it sufficient to look at the output when the generator is connected to a "friendly" resistive-only load, such as an oil-filled space heater. In the real world any product attached to a generator presents a combination of resistive, capacitive, and inductive loads. Moreover, modern loads which use switch-mode power supplies and their ilk present a non-unity power factor to the source. This introduces yet more non-linearities.

Summary: there is no one acid test nor manufacturer's scope trace which can be used to determine the "cleanliness" of the power *as presented to a specific load*. That said, modern electronics are remarkably accepting of a wide variance of power line perturbations, both periodic and episodic.

Wrooster

 

[rhett]

Mark,
OK, I think I got it now. To better know what exactly I have, it needs to be put on an oscilloscope to see. TroyBilt units are manufactured by Briggs&Straton, finding online support is tough. I do not think they get this kind of question much. Also, of searches and manufacturer literature's I have never seen any charts are info about it, just minimal discussions. The Power Inverters however have Pure Sine wave discussed allot because of the Solar and Wind Power On & Off Grid Alternatives. I had a Power Inverter go in a Puff of Smoke, 12v DC to 120v AC, on it's second use. (Stanley) I wish I could find a Power Inverter that uses the IGBT Technology, that information is not easily found though.

I have a gut feeling the gen-set is clean enough. No signs of a dirty signal on sensitive electronics while running the fridge, window A/C, microwave, lights, PC, TV all at once, and nothing has fried yet. For Katrina and Gustav it was a champ, being without grid power for about a week and a half both times. Recently got a 1500w to supplement and for fuel economy. Still might get an even larger generator, more time will tell.

I agree with wrooster, tests should be done with varied load conditions, even though the welder would be the only item run during it's use. I only wonder how much it will cost to satisfy my curiosity?

Thanks
Rhett

 

[wrooster]

Mark,
I agree with wrooster, tests should be done with varied load conditions, even though the welder would be the only item run during it's use. I only wonder how much it will cost to satisfy my curiosity?

You are over-thinking this.

Hook it up, and put it to work.

Wrooster

 

[rhett]

You are over-thinking this.

Hook it up, and put it to work.

Wrooster

Yup
Will Do

Thanks
Rhett

 

[Soundguy]

look at the physics of power generation with a generator, and with an inverter.

an inverter uses dc power and approximates a sine wave. the more steps, the better it looks.. and the 'cleaner it is.

in general, ac power produced via inverter is not as clean as generator based output.. which.. is bascially made the same way the power company dows.. with a ball of copper and magnetic fields.

much cleaner sine wave.

you might be surprised at looking at your grid power and a good genny output on a graphing oscope or meter. my 12.5kw northstar genny has better regulation and freq control than my utility power emi/rfi is what you want to avoid. a good filter setup on a genny will usually make VERY clean power for the average homeowner use..

soundguy

How does one determine if they have a "clean power" generator?

I ask because, Mark @ Everlast and their website state some of their Inverter machines would be suitable for use with a "clean power" generator. My needs are for field use and remote locations without Grid-Power.

Mark, if you read this, I have a TroyBuilt 5550w continuous/8500w surge generator and would like to use a PowerArc 160 or a PowerArc 200. 1/8" rods are what I will burn for most every project. My genset runs my Lincoln WeldPac 155 OK, but 6010 and 7018 weldments are preferred. I would not want to buy an Inverter machine and only ruin it from not asking the question.

Thanks
Rhett

 

[wrooster]

you might be surprised at looking at your grid power and a good genny output on a graphing oscope or meter. my 12.5kw northstar genny has better regulation and freq control than my utility power

How did you determine frequency stability was better on the generator?

Wrooster

 

[Darren]

If you're concerned about the power to sensitive electronic devices, use a UPS like a Clary as an interface. A Clary UPS uses the input power from the outlet only to charge internal batteries. Another circuit draws power from the batteries to produce clean sine wave output for sensitive equipment. Clary stopped selling to the consumer market maybe ten years ago. Most of their units are used for medical, military and computing equipment needs. The small ones are about the size of the largest rural mail box.

The units occasionally show up on eBay but seldom sell even though the asking price is a fraction of new. Apparently no one knows what they are. Probably the only thing a new unit would need is replacement of the gel batteries.

FWIW, Years ago I read about a lightening strike that destroyed everything connected to wiring in a home with the exception of several computers hooked up to a Clary. The Clary died, but the lightening never got through to the computers.

 

[wrooster]

If you're concerned about the power to sensitive electronic devices, use a UPS like a Clary as an interface.

The old Clary is an example of a "online" UPS:
Uninterruptible power supply - Wikipedia, the free encyclopedia

Contrast with an "offline" UPS, such as the type you find at Walmart:
Uninterruptible power supply - Wikipedia, the free encyclopedia

Wrooster