Honda Gen Volts/Hertz question

[alecmcmahon]

I have a 2nd hand Honda EM5000SX gen.

It starts on the first pull and runs fine, was doing a house run test and noticed some lights flickering on and off pretty heavily.

At no load the unit really doesnt idle, it sounds more or less the same at idle and with 10 amps on it.

Pulled out my voltage meter,with the house putting out a 10-14 amp load, im getting 118-121 volts, but 44-50 hertz.


I'm guessing it's the Automatic voltage regulator, but wanted to touch base with somebody with more experience before spending the money.

Thanks.

 

[ishiboo]

The frequency if accurate is directly related to the engine speed speed. It shouldn't be fluctuating and definitely not 6hz. Does the engine sound like it's loping?

The automatic voltage regulator, as the name implies, regulates voltage. As the voltage is correct (120v) I wouldn't suspect that as an issue at all at this point.

 

[alecmcmahon]

The frequency if accurate is directly related to the engine speed speed. It shouldn't be fluctuating and definitely not 6hz. Does the engine sound like it's loping?

The automatic voltage regulator, as the name implies, regulates voltage. As the voltage is correct (120v) I wouldn't suspect that as an issue at all at this point.

Engine runs pretty consistent, it'll get louder with more load as it should.

 

[Fallon]

The speed the generator spins at = Hz. So to get the proper consistent 60hz, your generator should always spin at the same speed, regardless of load. If you see the Hz fluctuating, you might have a bad governor. If it's just consistently off by a certain amount, you might need to adjust the governor.

It sounds like your voltage regulator is working properly if you are getting 120v +-2v, that's better than I get from the power company.

This isn't true for inverter generators as the inverter puts out 60hz regardless of what the engine & alternator or generator part is doing.

 

[goodwrench]

sounds like the engine not turning 3600 rpm's. the engine must turn 3600 rpm's at all times to make 60hz, 1 watt or 500. if you hz are low and you have verified your meter is accurate by checking utility power, the the engine rpm's need to be brought up so that the hz are like 62 no load. the voltage regulater does nothing with the hz, hz is solely controlled be the engine rpm's. the voltage regulator controls voltage which appears to be working correctly. also before going and adjusting rpm's, check the linkages and springs for binding, check to see if it has an idle down feature, and make sure it is working correctly. if everything checks out, then increase rpm's to correct hz under NO LOAD. also hz will drop some under load, especially heavy load so keep that in mind. adjust the rpm's with the screw on what would be the throttle control. if you need more help I can give you a better description. seems a little odd that the hz are of that much so check everything else before adjusting rpm's.

later!! Chris

 

[theoldwizard1]

CAREFULLY bend the governor linkage to increase the RPM.

 

[rlitman]

sounds like the engine not turning 3600 rpm's. the engine must turn 3600 rpm's at all times to make 60hz

Exactly.

Conversely, if it is really putting out between 44 and 50 hz, the rpm would be "hunting" between 2640 and 3000. It would be CLEARLY audible that the engine speed is going up and down in RPM. In fact, the difference in sound should be much clearer than the difference in light intensity. You would also hear synchronous motors that run on the generator vary in speed to match the generator (so that hunting or surging in RPM would be audible in the background noise of an air conditioner or refrigerator powered off the generator for example).

Don't go adjusting the governor linkage if this is not the case.
And remember that if you do adjust the linkage to bring up the RPM, you'll need to adjust the excitation to bring the voltage back down into line.

But my guess is that if it is surging, you probably have a clogged carburetor. Fix the carb issue (lean condition), and the RPMs will return to normal, and so will your power quality.

 

[alecmcmahon]

ok, well went back at it and adjusted the governor screw.

Brought the hertz up to about 55hz, but it brought the voltage up to about 128... ok fine, put the house on load ( nothing major, about 10 amps ) everything ran consistent and excellent for about 10 minutes, then the lights started to flicker pretty heavily, noticed on my voltmeter which was plugged into a kitchen outlet that the voltage just randomly dropped to about 108 and back in the mid 40s for hertz.

This is an older unit, i'd say maybe 8-12 years i'm guessing, Might the brushes need replacing? Would this make sense in any sort of way of my issues?

 

[iron block]

everything ran consistent and excellent for about 10 minutes, then the lights started to flicker pretty heavily

Any chance the load changed -- like the fridge compressor kicking in, perhaps? Or maybe a fan motor in the furnace?

It would be interesting to run the genny with just something like a couple of 500 watt work lights. Or a toaster oven. Anything that would load it up to 10 amps or so.

In other words, try testing it when not powering the house circuits at all, only running with a stable load that you control.

If it still acts up then, break out the carb cleaner like rlitman said.

 

[Pwrgeek]

Run it for a good long time with a purely resistive (lights, hair dryer, toaster, etc) load. Let the carb get cleaned out and the engine get fully up to temp. Then see how it does.

 

[rlitman]

Hair dryer and heat gun are my loads of choice.

 

[TheEquineFencer]

Run it for a good long time with a purely resistive (lights, hair dryer, toaster, etc) load. Let the carb get cleaned out and the engine get fully up to temp. Then see how it does.

Yes, do the above before you start screwing with the linkage and such.

If it's an older "conventional" generator, you probably have trash in the carb. I'd look real close at the main jet and the plugs/fittings.

500W lights and space heaters make a good load bank for testing.

I'd try cutting the fuel off and let it run out of gas, then remove the fuel line and fill the carb with some good carb cleaner and let it sit for an hour, reconnect the line and get it running again. It'll probably not run right then because the crud in the carb breaks loose and stops the main jet up if your luck is like mine. Then pull the carb if you cannot blow everything out with it on the engine. A set of torch tip cleaners work great on the carbs small passages. Hz at full load should be at 60Hz +/- 1hz. Mechanical carbs can get set at as high as 64Hz no-load.

With a little "tweaking" on the governor you can adjust the "droop" so there's not much change from loaded to unloaded, but you have to have a good understanding how it works to do it.

 

[simpler=better]

Hair dryer and heat gun are my loads of choice.

They're cheap too

 

[Slowgsr]

Beware of damaging electronics. That's all I have to say, I dont really want to get started

 

[theoldwizard1]

Run it for a good long time with a purely resistive (lights, hair dryer, toaster, etc) load.

Just so that you know, anything that has a coil of wire is NOT "purely resistive" in an AC sense. It is also an inductive load. Maybe not as much as a motor, but still there is a lot of inductance.

 

[alecmcmahon]

Well,

at no load it was running about 62 hz and 128 volts. let it run for a little bit, then just powered up my garage ( back fed thru garage sub panel ) lights and such ran just fine, let it run for a little, monitored volts and hz, stayed about the same( 2-3 amp load ) then I turned on a drill press and would cyle on an angle grinder a few times ( 9-12 amp load ). Ran ok for a few minutes, then it started to really drop in voltage and hertz, 10X volts and around 40-45 hertz. Shed some of the load and tried to get it to recover, but never did. Tried adjusting the gov. screw to raise the frequency and nothing really changed.

Packed it in, hopefully I dont need it for the coming blizzard in our area.


side note: I pulled out my little 85$ dollar harbor freight 800 watt 2 stroke gen, *just in case* the thing puts out a pretty steady 60hz 119-125 voltage with running an angle grinder off it. Funny.

 

[theoldwizard1]

All this talk about generators, I figured I had better start mine up ! It been at least 2 or 3 (maybe 4 or 5) months. Pulled it put of the garage (after shuffling around the junk stacked in front of it) turned on the fuel (E10) and it started on the second pull !

I let it run my 2 hp 240V compressor (with the drain open) for about 15 minutes. Shut off the fuel and let the engine run the carb dry. Everything back safely in the garage.

 

[theoldwizard1]

Well,

at no load it was running about 62 hz and 128 volts. let it run for a little bit, then just powered up my garage ( back fed thru garage sub panel ) lights and such ran just fine, let it run for a little, monitored volts and hz, stayed about the same( 2-3 amp load ) then I turned on a drill press and would cyle on an angle grinder a few times ( 9-12 amp load ). Ran ok for a few minutes, then it started to really drop in voltage and hertz, 10X volts and around 40-45 hertz. Shed some of the load and tried to get it to recover, but never did. Tried adjusting the gov. screw to raise the frequency and nothing really changed.

I ASSUME that when the voltage and frequency went out of spec, that the engine was still running smooth, correct ?

Some non-inverter generators have an a voltage regulator inside. Sounds like it is bad.


EDIT :

HONDA EM5000S EM5000X EM5000SX 32350-ZB4-632 Replacement Generator AVR - Amazon $80

 

[theoldwizard1]

side note: I pulled out my little 85$ dollar harbor freight 800 watt 2 stroke gen, *just in case* the thing puts out a pretty steady 60hz 119-125 voltage with running an angle grinder off it. Funny.

I hope you replaced the spark plug ! The original that came with it usually does NOT last much past the break in period. Get an NGK or Denso. Get a spare also.

 

[Slowgsr]

Good thing for checking, but do not use that generator. 60hz is very important.

You can repair it im sure for an affordable price and it will serve for many years to come

 

[Pwrgeek]

Just so that you know, anything that has a coil of wire is NOT "purely resistive" in an AC sense. It is also an inductive load. Maybe not as much as a motor, but still there is a lot of inductance.

You got me there. When I said purely resistive I really meant dumb with no sensitive electronics (though some toasters nowadays fail that one) or large motors . You want something that will put a large load on the unit without being sensitive to fluctuations in voltage or frequency (within reason). What you are trying to do is run a good amount of fuel through the carb to try to clean out the crud and get the whole thing up to full operating temp to see if it will settle out. Neither of those are going to happen with it idling with no load. Hair dryers and heat guns tend to work, though my device of choice for this chore is a 30 year old space heater that I think you could plug in to just about anything and it would work.

 

[theoldwizard1]

I have a 2nd hand Honda EM5000SX gen.

It starts on the first pull and runs fine, was doing a house run test and noticed some lights flickering on and off pretty heavily.

Follow up ?

 

[TheEquineFencer]

Follow up ?

Yeah, it'd be nice to know.

 

[afbrian13]

I for sure wouldn't want to use it like that. Nothing likes running at a low freq, but it will damage motors for sure. Maybe not immediately, but it shortens their life.

Haven't messed with many little generators like that, but looking at it like any other small engine it sounds like the carb needs a good cleaning. I'd bet the Jets are all varnished up. People never take care of them like they should.

 

[nadogail]

I have a gene set with a 13hp Chonda, Chinese made Honda clone. Would not run, except on sprayed starting fluid, bought a new carb for $10 on Amazon; that was the end of the problem.

The gas tank is not a place for long term gasoline storage. Ethanol is trouble waiting to happen, the legislators who voted to include in our gasoline should not be re-elected.