Before you buy a Chinese generator:

[theoldwizard1]

I had a good talk with my friend who sells generators. He bought a testing device to check the hertz a unit puts out. They should be 60 hertz, but many of the non sine wave units are all over the place, even top name units. Every sine wave unit is at 60 hertz when tested. The tester is very expensive, over two grand.

Generator Voltage and Frequency Meter $19.85

Many DMM include frequency.


Pseudo-sine wave inverter "confuse" most frequency meters because their input conditioning circuit assume they are looking at a sine wave.

 

[e-tek]

This weekend I'm going to add a plug-in receptacle to our furnace and water heater.....guess I could put it right at the on-off switch that's on the furnace already.

Any difference for a HE furnace??

 

[TheEquineFencer]

I have noticed that often you need to turn up the RPM on them to get the correct voltage. This is easily done by turning a screw. I have over 300 hrs on the little 900W HF unit and I'm very impressed with it....After turning the RPM up enough to achieve 120V.

As delivered it put out 103V.

I would never think of using it for a computer. It will run my mom's Oxygen generator(I have bottles of Oxygen for backup as well as a 2nd Generator)and the refrigerator at the same time!

RPM changes the Hz, the USA runs on 60 Hz, get a GOOD meter and check it! Electronics does not like over/under Hz.

 

[chris142]

RPM changes the Hz, the USA runs on 60 Hz, get a GOOD meter and check it! Electronics does not like over/under Hz.

You are correct. Stock they run about 105v and 50 hz. Turning them up to 120v gets you 60 hz

 

[rockwithjason]

I agree. The neutral/ground bond should have made a 70-80v difference unlikely.
Perhaps something was miswired in the generator hookup. A neutral/ground voltage difference might occur if the furnace or water heater was plugged directly into the generator and the generator not properly grounded.

I wonder if a multimeter expects to see a sinewave when measuring frequency and may not read properly on an inverter modified sinewave, which is more like a square wave.

yup, the neutral bond is the issue. how many of these units were bonded to ground via the ground rod or ufer ground? i bet none. without a connection to the grounding electrode there is no ground reference and that is why you see less than 120v to ground. most generators have a lug on the frame for connecting a grounding lead.

 

[racedaymechanic]

I work for the Company (Rato) that manufactures every of the Chinese Gens you can find, I can tell you that every Generator that ships out is tested under Load and they pull 100% of Rated load and Hz, Not sure where this bad info is coming from but its BS

 

[TheEquineFencer]

I have no problem with cheap generators that work as they should, but a lot of them don't is all I'm saying. I'm just saying check what you have to be safe.

 

[ishiboo]

My guess is this related specifically to cheap inverter generators, and not cheap "Chinese" generators in general. If a whole bunch of "Chinese" generators only truly put out 80v, stuff simply wouldn't work... not just flame rollout sensors.

Inverter generators, on the other hand, can (the cheaper ones) show 80v to ground and be operating 100% correctly, because the neutral is NOT at the same potential as ground but the opposite of the hot. In a normal AC system, you have +120v RMS because the neutral is at 0v (bonded to the ground at 0v) and the hot goes between -170 and +170.

In many inverters, the neutral is hot... i.e. you have +85v on hot, -85v on neutral, for a difference of 170v = 120v RMS. Ground is correctly at 0, so measuring "hot" gives you something that looks weird, but measuring between hot and neutral shows a correct 120v.

This is why these inverters cannot be hard-wired to AC systems, and really break down when an appliance incorrectly bonds neutral to ground which is not allowed.

 

[Gary S]

Lumping all Chinese made generators into the same quality category doesn't make sense to me. I suspect some work better than others, just like any product.
As already stated, many problems come from improper hookup of the generator.

I have a "Chinese" Generac generator. I have not checked the frequency of the output, but it does operate my electronics with no issues. I did put my meter on it the last time I had it running. It measured 120.3v on one leg, and 120.1v on the other one. It measured 240.4v across the two legs. The generator is rated at 6500w, and I loaded it past 6000w with no issues.
But, I did have it properly wired with 2 hots, neutral, and ground.

 

[ishiboo]

BTW... my math is wrong on the hot/neutral obviously in the inverter scenario, but anyway the neutral is not at 0 potential

 

[wyliesdiesels]

yup, the neutral bond is the issue. how many of these units were bonded to ground via the ground rod or ufer ground? i bet none. without a connection to the grounding electrode there is no ground reference and that is why you see less than 120v to ground. most generators have a lug on the frame for connecting a grounding lead.

FYI- a ground rod or UFER ground has nothing to do with and is completely different than an EGC(equipment grounding conductor). People often confuse the 2 all the time and i suspect it has to do with both having the same word 'ground'. A ground rod or UFER ground is for grounding out and protecting against lightning strikes. An EGC is for clearing ground faults. 2 completely different things. Whether a generator is bonded to a ground rod or not, will not change the relationship between its neutral and EGC. And most generators are factory shipped with the neutral bonded to the frame/ground/egc of the generator!

I agree. The neutral/ground bond should have made a 70-80v difference unlikely.
Perhaps something was miswired in the generator hookup. A neutral/ground voltage difference might occur if the furnace or water heater was plugged directly into the generator and the generator not properly grounded.

I wonder if a multimeter expects to see a sinewave when measuring frequency and may not read properly on an inverter modified sinewave, which is more like a square wave.

Incorrect. If neutral and ground are NOT bonded, then they have no reference to each other.

I work for the Company (Rato) that manufactures every of the Chinese Gens you can find, I can tell you that every Generator that ships out is tested under Load and they pull 100% of Rated load and Hz, Not sure where this bad info is coming from but its BS

EDIT: While the generators your company makes are probably good, I have seen first hand the harmful effects caused by SOME Chinese generators under performing under rated and advertised load.

 

[TheEquineFencer]

While the generators your company makes are probably good, I have seen first hand the harmful effects caused by chinese generators under performing under rated and advertised load.[/QUOTE]

I would not knock all of the cheap Chinese generators. I would just put them under load and check them. His company may build some good stuff. I'd just check what you buy. There seems to be several generators out there that do not perform as exspected. Know what you have and do your homework.Its not always non-domestic, USA made generators can be bad too. Know how to test and see what you have, do not trust just "because it burns a light bulb" it's right.

 

[wyliesdiesels]

I didnt mean to knock ALL Chinese generators. I edited my post!

 

[Highbeam]

So many folks are hung up on USA made or chinese made or mexico made. This is an international economy and I would bet that all generators contain something made overseas.

 

[dimarcelli]

fwiw i know the champion brand generators are made quite well. I know of one guy who has over 2000 hours on a small i think 2500 watt one. They all have cast iron cylinder liners and 100% copper windings. I have the 5000 watt model and it seems to be much more sturdier and generally built better than other chinese models i think. The fit of everything is very accurate and it always runs well.

 

[wyliesdiesels]

fwiw i know the champion brand generators are made quite well. I know of one guy who has over 2000 hours on a small i think 2500 watt one. They all have cast iron cylinder liners and 100% copper windings. I have the 5000 watt model and it seems to be much more sturdier and generally built better than other chinese models i think. The fit of everything is very accurate and it always runs well.

Really? Your model must have been a premium model cause the champion i used had ISSUES!!

 

[Stuntmonkey]

As luck would have it both my generators are USA made so I don't have any problems.

Because everything made in the great us of a works perfectly everytime, all the time.

 

[Wangstang]

I work for the Company (Rato) that manufactures every of the Chinese Gens you can find, I can tell you that every Generator that ships out is tested under Load and they pull 100% of Rated load and Hz, Not sure where this bad info is coming from but its BS

By chance, do you mind listing a few of the brand names your company manufactures? Since it sounds like your company ensures quality control on every propduct that rolls out to the customer, I'd feel comfortable buying their products.

The Harbor Freight, Predator branded, generators have my attention currently, especially the 7000/8750 model that they have on sale for $499 if you use the coupon:
http://www.harborfreight.com/420cc-8750-watts-max7000-watts-rated-portable-generator-68530-8561.html?ccdenc=eyJjb2RlIjoiMTg3MTAyMDgiLCJza3UiOiI2ODUzMCIsImlzIjoiNDk5Ljk5In0%3D

But I'm not sure i can trust the quality control.

Wes

 

[racedaymechanic]

By chance, do you mind listing a few of the brand names your company manufactures? Since it sounds like your company ensures quality control on every propduct that rolls out to the customer, I'd feel comfortable buying their products.

The Harbor Freight, Predator branded, generators have my attention currently, especially the 7000/8750 model that they have on sale for $499 if you use the coupon:
http://www.harborfreight.com/420cc-8750-watts-max7000-watts-rated-portable-generator-68530-8561.html?ccdenc=eyJjb2RlIjoiMTg3MTAyMDgiLCJza3UiOiI2ODUzMCIsImlzIjoiNDk5Ljk5In0%3D

But I'm not sure i can trust the quality control.

Wes

Yes we (Rato) do build the Predator Generators

 

[Wangstang]

Yes we (Rato) do build the Predator Generators

You have a PM.

Thanks
Wes

 

[ishiboo]

By chance, do you mind listing a few of the brand names your company manufactures? Since it sounds like your company ensures quality control on every propduct that rolls out to the customer, I'd feel comfortable buying their products.

Have you not been following the Raven MPV?

The Harbor Freight, Predator branded, generators have my attention currently, especially the 7000/8750 model that they have on sale for $499 if you use the coupon:
http://www.harborfreight.com/420cc-8750-watts-max7000-watts-rated-portable-generator-68530-8561.html?ccdenc=eyJjb2RlIjoiMTg3MTAyMDgiLCJza3UiOiI2ODUzMCIsImlzIjoiNDk5Ljk5In0%3D

But I'm not sure i can trust the quality control.

Wes

I bought that model to augment my Briggs 6500W, as I want to build an experimental autostart controller and needed something with electric start. I am very impressed - it starts instantly (including right out of the box) and runs great. Have used it for backup power outages *3 times* already this year and it's been flawless.

The smaller Predators are Honda clones and seem like they're built to fairly exacting standards.

 

[JakeKohl]

Newer one might be a true sine wave versus a modified square wave.

I think many of you are confusing DC to AC voltage converters with Generators. Many DC to AC converters do create a modified wave pattern that doesn't work with things like variable speed motors and can sometimes give electronics trouble (however, most computers convert the AC to DC power to run everything anyway...so it's of little consequence).

Generators create electricity mechanically and, by nature, are true sine wave. Ground setup can be an issue. True frequency and voltage produced are usually the culprit behind compatibility issues because this is a function of the engine speed...which can be fine tuned and can be affected by many different things (a lack of maintenance for one).

 

[ishiboo]

I think many of you are confusing DC to AC voltage converters with Generators. Many DC to AC converters do create a modified wave pattern that doesn't work with things like variable speed motors and can sometimes give electronics trouble (however, most computers convert the AC to DC power to run everything anyway...so it's of little consequence).

Generators create electricity mechanically and, by nature, are true sine wave. Ground setup can be an issue. True frequency and voltage produced are usually the culprit behind compatibility issues because this is a function of the engine speed...which can be fine tuned and can be affected by many different things (a lack of maintenance for one).

True when it refers to mechanical (alternator) generators, however the newest fad is "inverter generators" which couple an inverter with a traditional generator. These can produce a square, modified, or true ($$$) sine wave.

The issue the OP talks about is certainly from inverter generators, because some do operate NORMALLY with a neutral that far off ground. A traditional portable generator would have a bonded neutral and ground both at 0v potential, and would not operate things correctly if it was putting out 70v.

 

[racedaymechanic]

Have you not been following the Raven MPV?



I bought that model to augment my Briggs 6500W, as I want to build an experimental autostart controller and needed something with electric start. I am very impressed - it starts instantly (including right out of the box) and runs great. Have used it for backup power outages *3 times* already this year and it's been flawless.

The smaller Predators are Honda clones and seem like they're built to fairly exacting standards.

The Raven is another story, It was designed here in the US China builds about 75% of the parts and it is then assembled here, Thats where the problems are, The generator and all the eletricals are built in China, They were assembled here when our parent company found out all of the problems the Raven was having they Fired everyone from the CEO down and took over, its pretty bad when It takes the Chinese to teach Americans how to build quality

 

[Hpozzuoli]

I took a chance on one of those silent diesel generators. I never researched them, but saw a new one on sale via Craigslist. The guy brought it to my house, showed everything to me, and let it run for 30mins with a small load while we talked. I bought it for 1k on the spot. I then decided to do my research after the fact. Wrong order, but it happens.

My brand is an apache. They have a real company out of Texas that imports them and sells under the apache brand.

http://www.apachepowerindustrial.com

Mine has around 75hrs on it since I bought it with less than 1hr. It's a diesel unit and a clone of the yanmar L100 10hp Diesel engine. I saw lots of issues with them breaking and parts failing. I felt like I just blew a grand on junk. I did get a full year warranty with it so I ran it as much as possible...no issues. I have had it for 3yrs now. I bought every replacement part possible from starter, valves, full gasket kit, injectors, etc...you name it I got it on hand just in case. Most of the parts are yanmar oem replacement parts which fit perfectly. Only the gasket set is not yanmar.

Maybe I got lucky, but mine runs and performs great. It's starts no matter how cold and doesn't have pre heat. It's actually running now for my bi weekly excercise as I type. I run my entire house off it, with the exception of my two (2) ton ac units. My house is gas so that helps with heat and cooking. The power seems clear and I have no issues with tv or computers while on generator power. I think it's like anything else. You only hear the bad things that happen. There have been thousands of these things sold and a small fraction comparatively with complaints.

I wouldn't say its for someone who thinks it can be stored and used only when needed. It needs to be run and maintained. Most of the generators people buy are made in china anyways with more reputable brands on the nameplate. I know the brand dictates quality control most of the time.

I am happy with what I have and it's been great. It's run for 3hrs straight and performed flawlessly. Sure it can die any minute but so can a generac or honda. I have every replacement part on hand so I think I am ahead of the game. It's a very basic engine and super easy to understand. Diesel once treated lasts a long time and is cheaper than gas now near me.

One of the things I liked about it was the enclosure. It does cut down on the noise quite a bit. In the warmer months I run it with the service door open to help with cooling. Even when hot it always runs at a constant temp and never attempts to cook itself. I saw the thread title and just wanted to share my experience with my chinese diesel generator. It's 10hp and I think it's 6k continuos and maybe 6500 peak. I know there is a calculation to determine this.

If anyone has questions about these or how I hooked it into the house I will be happy to share. I have torn this thing down once to get familiar with it so I can be efficient if I have a problem during an outage. The enclosure comes off very easy after 50 or so bolts and disconnecting the fuel lines. I need to get some better rubber washers to go on the oil drain. I only had the garden hose type last time I changed the oil and they are leaking a tad. She burns no oil and has no leaks other than my human caused one.

 

[Hpozzuoli]

Here's an inside shot. It has a few access plates around it for quick access. Only thing I wish it had was access on the top to get at the injector and valves. Some different brands have that access.

 

[LS6 Tommy]

I had a good talk with my friend who sells generators. He bought a testing device to check the hertz a unit puts out. They should be 60 hertz, but many of the non sine wave units are all over the place, even top name units. Every sine wave unit is at 60 hertz when tested. The tester is very expensive, over two grand.

My <$200.00 Fluke multimeter will read frequency. Maybe he bought a scope to read the actual sine wave? That could be spendy...

Tommy

 

[Wangstang]

Harbor Freight has a new generator in my latest flier item 61725 . 13500 watt running output...no mention of surge/starting output and its not on the website yet.

Wes

 

[TheEquineFencer]

Hpozzuoli, good post. It's always better to do a little checking and testing to be safe. Yanmars are decent engines, they seem to smoke a little w/o a load but clear right up under load from the ones I worked on when I was at Cummins. A co-worker bought a 10K Yanmar for his dad, a freind of mine, it sat for 4-5 years until Hurricane Floyd came through. He went out to crank it and the bateery was dead, go figure 4+ years and not started. He tried to pull start it and gave up and called me, I asked if he'd set the compression release. OPPS, no he didn't, he set it and it fired and ran after 4-5 pulls. He was one happy camper. Diesels are nice, they can stand sitting around much btter than a gas engine, LPG is nice too, as long as you know someone at the gas company. They'll eat your lunch in the long haul on fuel with a real load.

 

[chewy7]

Harbor Freight has a new generator in my latest flier item 61725 . 13500 watt running output...no mention of surge/starting output and its not on the website yet.

Wes

get a picture of it

 

[c.snyder]

I have two champion brand generators. One is a 5kw unit model 41115 and the other is a 7kw unit, model 41532. I've yet to use them for backup during a power outage, but yesterday i was able to get them out for a monthly test run. Both were running a little "hot", zero load frequency was 62.8 - 63.

I tuned them down a little so they're producing about 61.92 - 62hz zero load and 60.3 - 60.8hz at 1/2 rated load. Volts are good at 124.5 - 125.

I know it's never going to be 60 spot on but i figure this is as good as it gets. As far as the build quality, both of these units are very nice. No wacky gas tanks or fittings. Good paint job and assembly. Everything seems to fit together nice.

 

[TheEquineFencer]

I have two champion brand generators. One is a 5kw unit model 41115 and the other is a 7kw unit, model 41532. I've yet to use them for backup during a power outage, but yesterday i was able to get them out for a monthly test run. Both were running a little "hot", zero load frequency was 62.8 - 63.

I tuned them down a little so they're producing about 61.92 - 62hz zero load and 60.3 - 60.8hz at 1/2 rated load. Volts are good at 124.5 - 125.

I know it's never going to be 60 spot on but i figure this is as good as it gets. As far as the build quality, both of these units are very nice. No wacky gas tanks or fittings. Good paint job and assembly. Everything seems to fit together nice.

Personally, I'd load them to 100% for a short time, maybe 1-2 minutes tops or until it's stable and check the Hz. Then remove the load and see what they are running at. I usually set one with a mechanical governor up around 63.5 hz at no-load then load it to 100% and see what Hz it runs at. Then I can go from there. If it's a Briggs and Stratton type engine, you can "tweak" the governor spring attachment a little and get the stability a little better if you're good. That way there's less "droop" from no-load to full load. I try to set one up so at 100% rated load it's at or very close to 60 Hz. I think Onan used to say 64Hz for the high side nd no lower than 59 Hz on the low side. I'm not positive, I'm sure that's pretty close to right.

 

[chris142]

My hf 3200-4000 one runs 59.5-60.0 hz.i guess i got a good one

 

[TheEquineFencer]

My hf 3200-4000 one runs 59.5-60.0 hz.i guess i got a good one

If you check the math and if it's at 60Hz full load, I'd say you did. Volts X Amps = Watts. Check your actual A/C output and the the amps load to see what you'regettig.

 

[Wangstang]

Harbor Freight has a new generator in my latest flier item 61725 . 13500 watt running output...no mention of surge/starting output and its not on the website yet.

Wes

The manual is here:
http://manuals.harborfreight.com/manuals/61000-61999/61725.pdf

I didn't see this model in my local store and it's not on the website so I've go no idea how the heck you can buy one.

Wes

 

[Chilliwack Murray]

Sorry all, I don't mean to sounds like a smartass but I have to clarify a few points. I've been in the generator business for 18 years and worked on everything from 500 watt units to 16 megawatt power systems.

On NON inverter units, voltage is the product of RPM and field strength (the faster the engine and alternator turn and the stronger the field, the higher the voltage). The voltage regulator is there to compensate for changes in engine speed as well as loading and should maintain between about 108 and 130VAC on basic transformer regulated units and significantly better on units with electronic regulators.

Frequency on this type of generator is directly proportional to RPM. Two pole alternators run at 3600RPM to produce 60Hz, 4 pole alternators run at 1800RPM to produce 60Hz. Mechanical governors should maintain frequency between 62.5 Hz no load and 59.5Hz at full load. Adjusting voltage by changing engine speed is only applicable to transformer regulated units. Do not adjust engine speed without checking frequency or you are likely to damage your electronics. Beyond 57 - 63 Hz, damage is likely.

Most electronics are far more frequency sensitive than voltage sensitive and surge suppressors cannot protect against incorrect frequency. As others have stated, many multimeters now measure frequency.

Regarding power quality, 1800RPM units produce a better sine wave and cleaner power than 3600RPM units and are less susceptible to harmonic distortion - preferable for electronics. Again, this applies to Non Inverter units.

INVERTER type units are DC generators that electronically convert the DC to AC voltage allowing them to run only fast enough to produce the required kW. Frequency "should" never significantly change on these however depending on the quality (shape) of the sine wave, many meters are unable to read this accurately. Also, as stated by others, many inverter units (regardless of quality or price) have a floating (ungrounded) neutral and can be damaged if it is grounded.

Many electronics will not operate and can be damaged by a severely distorted sine wave whether from an inverter unit or conventional. This is much more likely on a 3600RPM unit than 1800RPM due to the smaller 2 pole rotor and field.

The moral: The closer you run any unit to it's capacity, the more likely you are to experience frequency or voltage fluctuations and possible damage. If you intend to run at capacity, keep watch on the voltage and frequency.

I hope this helps someone avoid damage during an outage or other emergency when they can least afford it. Sorry to ramble on.

 

[Rob_b]

just for giggles...I have a meter at home that I am going to be using to do power check at one of my sites that I will hook up to my Generac 4000XL to verify the output etc. It is a Fluke 435 II http://www.fluke.com/fluke/caen/pow...ower-meters/fluke-435-series-ii.htm?PID=73939 and I think I can get some good readings using it. details to follow...

 

[TheEquineFencer]

just for giggles...I have a meter at home that I am going to be using to do power check at one of my sites that I will hook up to my Generac 4000XL to verify the output etc. It is a Fluke 435 II http://www.fluke.com/fluke/caen/pow...ower-meters/fluke-435-series-ii.htm?PID=73939 and I think I can get some good readings using it. details to follow...

I like the meter, did you pick it up in a pawn shop? I'd love to have one like that. Not only will you be able tp read the Hz, but the wave form also.

 

[Rob_b]

No, it belongs to my employer. As much as I'd like to own one, they are always coming up with new stuff. The list price on these things makes it cost prohibitive for just being a garage queen meter. They come in about $7-8K. This one gets calibrated yearly. I love using it to trouble shoot power issues on site. It can generate reports on so many things that there is nothing able to hide in the background...Harmonics, flicker etc

 

[Blue Jim]

Looking to buy a generator and found the information to be valuable