Governors in general, shouldn't do that.

I have seen a lot of the cheap Chinese generators oscillate like that, though - most likely due to a combination of slop in the linkage, sticky linkage, and cheap design. The fact that it is on the lean side probably aggravates the problem, too.

Not too much of an issue with a light bulb or heater, but I would be cautious about running sensitive electronics off of it.

 

Thanks, it is of value to know that my would not be considered "unusual"... defective should I consider complaining to the supplier. The very cheap rotary mowers I've owned over the years did not have any noticeable rpm hunting when unloaded, however, they do have the flywheel effect of the cutter blade.

I'm not worried about electronics. About all I'd run on it is a few CFL bulbs, the blower on my fireplace (assuming cold weather) air tight insert and charge my deep cycle batteries. On our last power outage, 4 days, I used the deep cycle batteries and inverters to run some of the same... I'd like to add the refrigerator, which the gas unit should handle. The generator provides a 12VDC output for charging batteries.

I understand the hunting will cause the frequency of the AC to hunt as well. I will put a frequency meter (Killawatt meter) to see what the frequency does. I could even look with my oscilloscope to see what the waveform looks like. But most likely will not go that far. I had read a review by one tester who said the waveform deteriorated from a sinusoid to more triangular under load. I have to admit it struck me as strange that a rotating machine could suffer such a distortion. I'd expect too much load to lower the voltage (due to IR loss) and reduce the frequency (due to lower rpm). Triangular? Strange to say the least, typing this raises my interest in putting an Oscilloscope on the output.

One big plus, the engine noise is not bad and it will run over night (over 8 hours) on a gallon of gas - assuming less than 1KW load.

An additional disappointment is one of the "Justifications" I made was that I could use the generator to run small electric tools, specifically the small chainsaw, far from electrical power. Even the 4 day power outage wasn't too bad as I had a good supply of hardwood fire wood and charged deep cycle batteries. The contents of our referigorator were lost however.

 

My hunch - and it's just a hunch - is that the tuning of the governor on a mower is different than that of one on a generator. If it were a process control I'd say that the PID loop was set up more aggressively on the generator than the mower. A mower can afford to lose a few hundred rpm under load in exchange for stability, but the generator has to do whatever it can to maintain rpm and thus frequency.

They are good for what they are, but no comparison to the quality of the output on a more expensive unit.

 

After you disconnect the load, and the engine is hunting up & down, what happens if you try to gently stabilize the governor linkage with your finger? If you get it settled down, then let go of the linkage, what happens?

What happens if you disconnect the load, promptly shut it down, and immediately restart it? Is it possible that what you're seeing is not a governor-linkage type of problem, but is because the engine is now running differently (you had a load on it, it's working harder, getting hotter, etc), and now perhaps it's running lean, which is causing the hunting/surging?

Does it smooth out if you choke it somewhat, while it's hunting? If so, it may be running lean. My generator surges (hunts) unless I have the choke on halfway. I think I need to clean my carb, but that's probably not your problem, being new.

It seems somewhat curious that the generator's engine actually stops when you turn on the chainsaw. Granted, it is probably calling for a lot of current when it tries to start. But it doesn't trip a breaker or anything. For curiosity, can you hook up ~2,000W of resistive loads? A hairdryer plus a few lights, something like that? Something significant that you could flick on all at once, to see if it's just the governor being unable to correct in time?

It makes me curious if you could try something like connecting your two lights, having them on, then turning them off and quickly starting the chainsaw? The engine would already be applying a bunch of throttle, I wonder if that could somehow help keep it from stalling? That could also backfire, of course When you shut off the lights the governor will quickly have to snap the throttle shut, to avoid over-speeding, so if you then re-apply a different load while it's throttling down, it could perhaps work against you. Just trying to think of things you could check/try.

If I had access to an oscilloscope, I would definitely check the output on mine. I've heard they vary, from just-OK to not-very-good. I'm curious how mine looks. I wonder if using a line conditioner would help protect more sensitive/expensive electronics (TV, etc). I wonder how the RPM changes would affect your fireplace blower? If it's an AC blower, would the motor be trying to speed up/slow down as the frequency changes?

 

Jerry, if possible, try attaching a very weak expansion spring to the throttle shaft arm on the carb and by use of a length of light wire, attach the other end of the spring to the governor arm to eliminate any slack in the attachment points of the rod between the carb and governor.
Mike

 

I can answer some of the questions, or rather give some more data that may indicate answers.

Keep in mind this is a new unit and even after some testing today has no more than a couple of hours run time on it.

This time I hooked the load though my "Killawatt" meter, a very nice device for measuring Volts, Amps, VA, Watts, Power Factor, Frequency, KWY, and elapsed time since plugged in. All measure that depend on the AC being a true sine wave may have errors, e.g., the RMS readings (digital display).

First I started the engine, hard to start, as usual. I guess it took at least 15 pulls to get it started. The meter showed 61 to 62 Hz for the frequency... and I could hear a slight hunting, but the meter showed no more than a 1 Hz variation. I am surprised my hear could pick up such a small change, but there is not doubt in my mind I could hear the engine hunting. Close inspection of the governor shows some very slight motion. I think clicked on the 150 watt flood light. The frequency didn't change more than 1 Hz, and settled into the same +1 or 2 over 60. The wattage read something close to 150, I now forget what, I think it was higher, maybe 160 watts. Obviously I didn't write anything down.

I think hooked up a 750 Watt electric heater (basically a resistive load) and the frequency quickly locked into the same range. The voltage read 121 VAC with very small variations regardless of the load.

The heat also has a 1500 watt setting. When I switch that on, the engine promptly died. I mean it stopped dead, not couple of cycles first. I had read a review of this generator before purchasing and that person said they could not get the unit to carry the advertized load. It is sold as a 2KW peak and 1.5KW steady-state. It clearly will not take 1.5KW, mine can't even hold it for a few seconds. This is not a big problem for me as far as using the unit on the next power outage... I've yet to check the refrigerator. It is clear to me this unit would not hold two or more refrigerators/freezers. If one had more than one they would at least have to switch between the two, never try to run both at the same time. I have not checked on what my refrigerator draws... lI may put the Killawatt meter on it tomorrow to measure.

The only electric tool I was planning to operate of the generator is the small chainsaw, an that's not going to happen. Maybe I can find another smaller chainsaw it can handle. Go figure, the 3 HP engine on the generator is much larger than the motor (power) on the chainsaw, yet the generator can not power the saw. The chainsaw (using 750 watts per HP) is just over 1 HP.

When my tesing killed the engine, I had no problem restarting it. The engine starts well when warm, but is not good when cold. That may be cold and dry, as it has sat for a two or three days before I started it today.

 

I would definitely try out the fridge & freezer (separately, like you said), to make sure it can actually handle them. Doing some quick reading through some reviews of the unit, a lot of people seem to have found similar results, that it maxes out around 12A or so.

If it can't start up an 8A chainsaw I'd be at least curious about the compressors in the fridge/freezer. The chainsaw can draw a *max* of 8A, when it's actually cutting. But when just trying to spin it up, there's no appreciable load on it, it's just the startup current. If you ran it through the Kill-A-Watt I'd be curious what it's actually drawing once it is spinning (just as a point of reference).

The fridge compressors have startup current to deal with, but they're likely also loaded at the same time. That's hardly conclusive as to whether it will work or not, but it's definitely worth checking before the power goes out.

I have a Kill-A-Watt as well, and found it very useful when we lost power for 2 days in October, which was the first time I had to use my generator. As you found, it let me keep an eye on the voltage and frequency as I added loads. You should be able to use yours to monitor your total draw. Mine has a rating of 15A/1875W, I think. I recently bought a clamp-on amp meter, so I can check the draw on each leg of my generator, which can go up to 2750W/leg.

If you think the unit is going to be marginal for the loads you need to keep running, it might be worth considering a used, higher-capacity machine? I got a used 5500W unit, made in the US, for what Amazon is charging for yours. Even a continuous 3000-3500W generator should be plenty for things that run on normal outlets. A friend bought a 3000W, I think, and had his furnace and fridge on it, and a fluorescent light or two, all running at once. The extra "headroom" might be worth it. Please don't misunderstand, I don't mean any offense, would just hate to see it leave you hanging when you really need it.

 

I would agree with RedOctobyr. If your generator is having trouble with a universal motor on the CS, it could have a real problem with a refrigerator or furnace, even though it should theoretically have the capacity. How much will this generator have really cost if you smoke the compressor in your refrigerator? I got this Honda from a scrap pile because the slip rings were shorted. The carburetor, starter, regulator and brush holder had been robbed from it. For $700 worth of parts and and the repair of the rotor, you have a nice generator. It's brand new, it was never used.

 

I will try to run refrigerator tests this week end, but I can say there is a rather professional writeup evaluation on Amazon which helped me decide the unit would work for me. I say this fully expecting to never need it, thus the disappointment it will not power my small electric chain say. I suppose a circular saw will fall into the same category.

The subject review said 10 Amp is about all (1200 watts) this unit can manage. But, the report goes on to say: [[I tested the generator simulating a power outage and it performed fairly well. It powered our natural gas central heating furnace igniter and blower motor, refrigerator, computers, bathroom exhaust fans, and lights -- all at the same time. ]] So I am rather confident it will handle my refrigerator. As for my furnace, I have a geothermal heat pump, nothing shout of 220 VAC at 20 amps will put that unit on-line. Thus, my survival heat strategy is an airtight fireplace insert and a supply of seasoned hardwood firewood. That on the last and worse outing I have experienced kept the house at about 60 degrees.

 

If yours stalls out trying to start a chainsaw, and his ran a furnace (with igniter), fridge, and some other stuff all at once, it sounds like perhaps there is something else going on.

I would have no reason to suspect his review, but I'm personally surprised he could run all that off 12 amps. I heard the exhaust tone from my generator change audibly when my natural gas furnace started, and the igniter came on (with the fridge running, and some lights). The igniter apparently draws quite a bit of power, and is a respectable load by itself (you could tell the generator was working harder).

My friend with the 3,000-3,500W generator had the furnace, fridge, and a few lights running. But when we turned on another incandescent light, we saw the lights start to brighten & dim a bit, and it sounded like we were getting near the limit of what the generator could provide. And that's running off a larger unit. Not exactly a scientific comparison, but I'm a bit skeptical of how the reviewer got all that running at once, without problems.

 

My limited tests, while monitoring with a watt meter, showed my unit held a 750 watt heater (6+ amps) easily. However, when I threw the heater switch to 1,500 watts (about 12 amps) the engine stopped dead. I'll report on what I find on my refrigerator. It is just a "normal" single door size (14 CF, don't know - refrigerator over freezer, two doors really).
This refrig is about 15 years old, so I assume it isn't as efficient as a new model, but that may not mean the compressor takes more power, it may just run more.

EDIT: Update 2:40 PM I put the killawatt meter on and was surprised how little power the refrigerator uses. It was running at about 170 watts (I could run this off my deep cycle battery and inverter for several hours per battery charge). The power factor was very close to 1, the power company has got to love this compressor. When I opened the door the power jumped to 210 watts due to the lights inside. Even without testing I am confident the generator I purchased will run this refrigerator and handle all my other limited needs with power to spare....too bad it can't take a higher start up current load. A couple pounds of flywheel would make a lot of difference.:thThumbsU

 

Cutting out like that, I wonder if it is more a function of the main jet being on the lean side.

I remember reading somewhere about opening up the main jets just a smidge with a number drill since they aren't adjustable.

What is your altitude above sea level? Being NJ it must be fairly low, which is going to need a richer mixture than if you had some elevation.

 

I picked up a used generator 3500 watt used at Lowes it hunts and smooths out @ half choke, pulled bowl and water and crud was in it. I still haven't cleaned carb yet I'm sure from what I seen it will certainly help.

 

To Oo-v-oO's point, what if you put the choke on partway, before adding the big loads that kill it? Not so much that it's smoking and faltering. Partially choking it will richen the mixture, and let you temporarily simulate opening the jet, I believe.

It's interesting you mention running off the inverter. Yesterday I almost mentioned my exploits trying to run my fridge off an inverter. A few years ago, during an ice storm where we lost power for 3 days, I tried (in desperation) to run the fridge off an inverter hooked to a car battery. It's supposedly a 300W, 600W peak, inverter. Plugged the fridge in, got nothing at all. Not even a click or anything, no lights. Didn't work for me, unfortunately.

I just checked my fridge with the Kill-A-Watt, and was puzzled to see 465W, with the compressor off, until I figured it out it must be defrosting. Opened the door and got 570W (wouldn't have thought the lights draw that much). It just finished defrosting and the compressor came on, it settled at 135W. With both doors open, 240W. (as an aside, I thought a power factor near 1 was good? My compressor PF seems to be 0.98)

 

I had discussed this lack of peak power on another forum. There it was suggested that the carburetor may be too lean to take the shock of high starting current. I haven't tried giving it some choke when switching on the chainsaw.

Yes, for the power companies a perfect load has a power factor of 1, resistive. That means the volt-amps and watts are the same and they get paid for all of it. High inductive (or capacitive, not that that is a problem) loads have a low power factor and leave the power company the problem of supplying high current (and associated transmission IR losses) that they can't charge for.

I hadn't thought about the defrost, that could be a killer. I wonder if my refrigerator has a switch to turn off the defrost cycle. I think my refrigerator has a couple 40 watt bulbs for light, thus about an 80 watt increase when the door is opened.

I may start the unit tomorrow and rund a cord inside to power the refrigerator, just to be sure. 465 watt load should not be a problem as long as I have only light other loads on the generator.:dunno:

 

Just curious, jerry_nj, did you make any more headway with this? Does it power the fridge OK, were you able to get it to start the chainsaw?

 

No, I have not done any more testing. I am convinced that the low power drawn by my refrigerator and the fact others have said they have run refrigerators off of this unit means it will run my refrigerator. My other guess is I will never have to try.

As for the small (14") electric chain saw I have not tried using a partial chock to see if that can hold the engine over the start-up current demand.

I was doing some low tree pruning work today, including some branches in the 6" diameter range, and got my gasoline 16" chainsaw out. The blade was so dull I decided to use an electric saw. I have a new 18" electric that is rated 4 HP (3KW) and requires 12 gauge extension cord. I think the recommendation is no more than 50'. I don't have any such extension cords and I have used the big electric on a 25' 16 gauge cord. Today I put the big saw an a 100' 16 gauge cord, and it started and ran just fine. This really demonstrates how "wimpy" my generator is. Hum I may try putting my small electric (800 watts) on the 100' cord, that may add enough resistance to lower the starting current to a level the generator can handle.

I will try these things and post my results...if I remember:thanku:

 

I have a new 18" electric that is rated 4 HP (3KW) and requires 12 gauge extension cord.

Unless it requires a special, 30A 120V outlet (which is unlikely), the saw isn't really making 4 hp. The same way that an air compressor that uses a standard outlet is definitely not 5hp. A 120V, 15A circuit can only supply 1800W, or 2.4 hp. From what I understand, sometimes the manufacturer's try to rate them based more on their startup current, which seems kind of ridiculous to me.

I think the recommendation is no more than 50'. I don't have any such extension cords and I have used the big electric on a 25' 16 gauge cord. Today I put the big saw an a 100' 16 gauge cord, and it started and ran just fine. This really demonstrates how "wimpy" my generator is.

The saw will probably work OK off a longer cord, but the voltage drop will reduce its power. If you were just cutting little stuff it might not be a big deal. I could see it being more of an issue when you go to cut something thick, and the motor's power demand climbs. As the current increases, the voltage drop through the long cord will increase. I've heard that when motors are run off voltage that's too low, they draw more current to try and compensate. That can cause things in the motor to overheat. I'll confess I'm not clear how being able to run the saw off a long cord correlates to your generator being weak.

Hum I may try putting my small electric (800 watts) on the 100' cord, that may add enough resistance to lower the starting current to a level the generator can handle.

I will try these things and post my results...if I remember:thanku:

I have no idea if it works that way for starting up motors, whether a long cord will make things easier on the generator. (the long cord will make things worse for the saw's motor) Inductive loads get more complicated, at least to me. I suppose it might work that way for a resistive load. Plug a space heater directly into an outlet, it gets 120V, and pulls, say, 12.5A, 1500W (so resistance would be 9.6 ohms). Put it on a long, thin cord, and maybe it only gets 110V, and pulls 11.45A, 1260W, based on the same 9.6 ohms. Though, in thinking about it, is that 240W wattage difference now simply being dissipated in the cord, and you're still drawing 1500W from the wall?

I was thinking about loads on long cords the other day (thinking about my generator setup), and was curious how much of a voltage drop there really is across a long cord with a big load. I realized you could check fairly easily with the Kill-A-Watt. Plug the KAW into the wall, and connect a heater/hair dryer. Something with a predictable load. Check the voltage with the heater off, and on (also note the current draw/wattage). Now plug your 100' cord into the same outlet, plug the KAW into the end of the cord, and connect your heater. With the heater off, I expect you'll see the same wall voltage (there's no current flow yet). But with the heater on, if you measured, say, 117V while running plugged directly into the wall, I wonder what the voltage will drop to after going through the cord. 110? 100? The amps/watts will drop by the same percentage.

But, again, are you always pulling the same wattage from the wall, but just dissipating it differently (all in the heater, or split between the heater and extension cord)? I guess it would be interesting to see the wattage reading on the KAW if you set it up as wall-KAW-heater, vs wall-KAW-cord-heater, vs wall-cord-KAW-heater.

Thanks for the update!

 

My brother in law has a few of that type of generator and he uses a snowmobile primer to start them cold. He made a brass tube that goes through the air box and is centered in the carb, a couple pumps and the genny fires first or second pull regardless of how cold it is.

 

Jerry--jumping a bit off your generator problem--but still you posted in it about an electric chainsaw--what kind is yours? I have an older 14 or 16 inch one that was given to me--all clogged up--i cleaned the blade and finally found a mnmew hain for it (odd size)--but cutting any amount or decent wood or any quick penetration just bogs it down---

Does yours do the same? One of the things I see right off is the chain bar has no sprocket at the end--just a round curve.....I am kinda dis= gusted with it--


glenn

 

One of the things I see right off is the chain bar has no sprocket at the end--just a round curve.....I am kinda dis= gusted with it--


glenn

I think those are called solid nose bars. The fact that there's no sprocket, with bearings, apparently makes them more tolerant of abrasive conditions. I've never used one, but those kind of bars apparently have their place, even in big saws.

 

My 14" electric (the subject I wanted to be able to run off the new generator) is a Remington. It cost about $69 at Home Depot. It has surprised me with the cutting power it has. I have kept the chain sharp and out of the dirt, including dirt in bark of the trees. I don't have it in hand, data may be in the beginning of this thread, but its steady state running power is about 800 watts, about 1 HP.

Now for some Electrical Engineering "101":

Inductive loads have high starting current that are mainly limited by the resistance in the source (extension cords add to this) including the "output impedance of the generator (for power from the power utility that is also wire resistance). Then, and a rotating machine starts to rotate it produces a "backk emf" (voltage) which further lowers the current. All these things are too short in nature to observe with a kill-a-watt meter (or other meter) a properly triggered oscilloscope could display them. This it the domain of the so called "slow blow" fuses of the past, and is a general characteristic of modern circuit breakers (frankly I don't know if there is such a thing as a slow blow circuit breaker). Thus, my speculation that more resistance in the delivery circuit (long low gauge extension) cord may drop the starting current sufficiently for the generator to keep running. Here the limiting must not be so great that it prevents the motor from starting (more slowly) rotating.

Power delivered from the source can be expressed (steady state is what I am referring to here) as the voltage (rms for ac) squared divided by the resistance (This is the power, not the volt/amp that is what the generator has to deliver) so if one adds resistance to a heating circuit the total power goes down, and some of it is delivered to, and out of, the extension cord. The so called IR drop (or E squared divided by R drop).

I may have missed some of the questions/issues, but my wife is calling with a "Hunny Do"... got to run..sorry about typos.

 

This it the domain of the so called "slow blow" fuses of the past, and is a general characteristic of modern circuit breakers (frankly I don't know if there is such a thing as a slow blow circuit breaker).

I'm not sure about residential stuff, but industrial circuit breakers are available with different time/current curves, much like fuses.

Sometimes it helps to make an analogy between water and electricity. Think of a heavy gauge extension cord as a garden hose, and a light gauge one as a length of fuel line. Both are the same length. With no flow, the pressure (voltage) is the same at the end of each, but as soon as you open the faucet (turn on the saw) the pressure drops off at the end of the small hose but stays almost the same at the end of the large one.
For a given hose size (wire gauge), you can only transfer so many gallons per hour (watts) and no more. If your water pump (generator) can supply 10 gpm (say, 1,000 watts, for round numbers) and your faucet (saw) only uses 8 gpm (800 watts) but your little hose (undersized extension cord) can't supply more than 5 gpm (500 watts), then the faucet (saw) isn't going to flow (cut) what it is capable of.

 

jerry_nj, good point. Adding the extension cord adds additional resistance. So if you add an extension between the wall and the device, with a resistive load, the total current & wattage will decrease. Though wattage will also now be dissipated by the cord.

Oo-v-oO, I like your analogy. Though I sometimes need to remind myself that it's *current* that determines how big a wire you need. Not explicitly wattage. Let's assume you need to provide 1800W. 120V and 15A though a given extension cord might be a problem. But if you take that same cord, and use 240V instead (assuming we don't need an additional wire; let's say we actually doubled the voltage through the hot wire, and didn't just add another wire in the cord from the "opposite" leg in your panel), now you only need 7.5A, and that cord may be fine. So perhaps gpm in your example is better compared to amps than watts. But if you're only talking about a single voltage in the example, then it's admittedly kind of moot.

That's one reason that, for example, there was a push a number of years ago to go from 12V in cars to 24V or 48V. For the same power, you need less current, so you could more easily supply power to hungry devices, and you wouldn't need big thick (heavy & expensive) wires to feed the starter, for instance. Insulation is easier to add than conductors.

Edit: This will sound really stupid, but sometimes I think of the water & pipe analogy in terms of how loud that pipe would be. The louder the pipe, the greater the resistive losses and heat through the wire. A lot of flow (high current/gpm) through a small pipe (small wire) will be quite noisy (so you're closer to the limit of what the wire can handle). That same gpm through a large pipe (wire) will be very quiet. That still applies when you consider changing pressure (voltage) to achieve the same power transfer. Changing an application from 120V 15A to 240V 7.5A is using higher-pressure water, at a lower gpm, which will be quieter through the pipe (you don't hear the extra water pressure in the pipe, just the flow/gpm). I know, it's dumb, but it's just another way to "visualize" the problem.

 

That's right, higher voltage allows for more power delivery at a given current, and the line loss due to IR drop goes down. That's the main reason we see the high voltage delivery systems bringing power to substations and then to our homes, again through a step-down transformer. I think the voltage on the residential street is in the thousands of volts range and on the tall metal towers in the hundreds of thousands volts. Thus, when a line is down, not go anywhere near it.

As the above suggest, one can move into a dangerous voltage range real fast, even 120 VAC can easily kill a person. Europe/elsewhere use 220 VAC for the basic residential outlet voltage. So, be even more careful if traveling outside the USA. Canada and I think Mexico use the same voltage and frequency (Europe is also 50 Hz, not 60 Hz) so that we can share/sell power across the national boundaries. I don't recall what South America does, but I guess all of SA uses the same and it is probably European standard. Europe had more influence on South America than the USA on standards for utilities (electric and telephone). But, I slip off-topic. Said another way, my generator would not work in South America : )

 

Agreed, I should have used amps and not watts in place of GPM in my analogy. Not sure what I was thinking, I know better.

 

I tried my 8 amp electric chainsaw with a 100' 16 gauge extension cord (adds about 1 ohm in series with the chainsaw - or drops 8 to 10 volts when delivering 8 amps). The chainsaw still killed the generator, stopped dead, almost immediately. I added another 40 feet of extension cord, 16 gauge again. The chainsaw still kills the engine.

I then took the suggestion and applied enough choke that the I could heart the engine dropped a few RPM and clearly sound different. It was, however, still running smoothly and the governor became very stable. I the hit the trigger on the chainsaw, still connect with the 100' extension cord. The engine held, and the governor advanced a small but visible amount. This seems to confirm the engine is set very lean (EPA in action, lowest emissions), the carburetor is not adjustable. The good news is, from the specs and what I have read this generator will run for 8 to 10 hours at 1000 watts on about 1 gallon of gas.

Conclusion, I can use the generator to operate my electric chain saw anywhere I can easily move the generator to. I still have gas chainsaws, and plan to continue to use them for tree work far from the house

 

Jerry, if you want to ream the main jet out, go to a welding supply and ask for a tip drill. It's about 4" long and has a collett on one end. Inside is an assortment of drill bits ranging from very small to extremely small. The're for reaming deformed holes in torch tips. Maybe a thousandth or two is all you need.
Mike