Sound(s) from Multiple Running Generators

[zzvyb6]

Our part of min-Michigan has a huge number of electric power districts out. Ice and falling trees is taking down poles, and causing transformer burnouts. We have power, but about a 1/8 mile away is a high-end subdivision/neighborhood, each with it's now running standby generator. You can easily pick up the drone sound from the common rpm between all these units. I could sleep thru this, but frequently there are loud thumping noises coming from there. I'm guessing that this is 'FM-ing' (Frequency Modulation) cause by individual generators catching up on a load from motors starting, wells running, etc. It's currently 21 deg F here, so furnaces are definitely running. What do you think is going on? Otherwise it sounds like the 'katerpillar drive' going bad on the Red October.

 

[Rustyiron]

I think that power companies can easily get complacent with tree trimming then you have a storm, nothing special just the right combination of snow, ice with a little wind and thousands of homes are out of power. The media blows this out of proportion and of course the residents are not used to this either and the frenzy grows. Urban areas are the worst, their idea of being prepared is to have their "devices" charged!

 

[Hay Dude]

I think that power companies can easily get complacent with tree trimming then you have a storm, nothing special just the right combination of snow, ice with a little wind and thousands of homes are out of power. The media blows this out of proportion and of course the residents are not used to this either and the frenzy grows. Urban areas are the worst, their idea of being prepared is to have their "devices" charged!

It’ll be interesting to see when some of these state bans on ICE engines under 25HP start taking affect in cold climates. That covers about 95% of every backup generator in the country.

I’m thinkin there’ll be a new thing called “people popsicles”

 

[turbo36]

Our part of min-Michigan has a huge number of electric power districts out. Ice and falling trees is taking down poles, and causing transformer burnouts. We have power, but about a 1/8 mile away is a high-end subdivision/neighborhood, each with it's now running standby generator. You can easily pick up the drone sound from the common rpm between all these units. I could sleep thru this, but frequently there are loud thumping noises coming from there. I'm guessing that this is 'FM-ing' (Frequency Modulation) cause by individual generators catching up on a load from motors starting, wells running, etc. It's currently 21 deg F here, so furnaces are definitely running. What do you think is going on? Otherwise it sounds like the 'katerpillar drive' going bad on the Red October.

 

[Rustyiron]

I very recently saw a tv show, "engineering disaster" iirc and that footbridge story was covered.

 

[orezok]

When the military marches across a bridge, they are instructed to break cadence as it can cause vibrations in the bridge that can cause failure.

 

[John_Mc]

Our part of min-Michigan has a huge number of electric power districts out. Ice and falling trees is taking down poles, and causing transformer burnouts. We have power, but about a 1/8 mile away is a high-end subdivision/neighborhood, each with it's now running standby generator. You can easily pick up the drone sound from the common rpm between all these units. I could sleep thru this, but frequently there are loud thumping noises coming from there. I'm guessing that this is 'FM-ing' (Frequency Modulation) cause by individual generators catching up on a load from motors starting, wells running, etc. It's currently 21 deg F here, so furnaces are definitely running. What do you think is going on? Otherwise it sounds like the 'katerpillar drive' going bad on the Red October.

I wonder if what you are hearing is the "beat frequency" caused by slight differences in the frequency at which the generators are running. They are supposed to run at 60 Hz. Most common generators (other than inverter generators) do this by running at 3600 RPM. If one generator is running at exactly 3600 and another is running at 3599 rpm. The sound of the exhaust pulses will sometime reinforce each other and sometimes interfere. This creates a "beat" at a frequency equal to the difference - in this example, that would be 1 Hz which humans can hear as a "thumping". With multiple generators running, I imagine you can get some rather complex sound dynamics going.

Without hearing the noise myself, I can't say that is what is going on, but it's a possibility.

Musicians sometime use beat frequencies to tune different instruments into sync with each other: rather than comparing one note to another, you can listen for the beat frequency. The slower the beat, the closer they are to matching. When the beat disappears, they are hitting the same note.

 

[zzvyb6]

I wonder if what you are hearing is the "beat frequency" caused by slight differences in the frequency at which the generators are running. They are supposed to run at 60 Hz. Most common generators (other than inverter generators) do this by running at 3600 RPM. If one generator is running at exactly 3600 and another is running at 3599 rpm. The sound of the exhaust pulses will sometime reinforce each other and sometimes interfere. This creates a "beat" at a frequency equal to the difference - in this example, that would be 1 Hz which humans can hear as a "thumping". With multiple generators running, I imagine you can get some rather complex sound dynamics going.

Without hearing the noise myself, I can't say that is what is going on, but it's a possibility.

Musicians sometime use beat frequencies to tune different instruments into sync with each other: rather than comparing one note to another, you can listen for the beat frequency. The slower the beat, the closer they are to matching. When the beat disappears, they are hitting the same note.

Yep. That's what I figured it is.

 

[diesel85]

I have very sensitive hearing, and I noticed this too.

One thing I have noticed is that I can hear most diesel engines running from a long ways away. They have a very low frequency that I can pickup.

What is really interesting is that my tractor (a BX2200) parked about 1000ft+ away will subsonically rattle my plates in my cupboard at certain engine RPMs. I can barely make the low frequency noise out.

I notice only diesel engines do this phenomenon.

 

[grsthegreat]

When power is out, the only time im upset is when i cant hear my generator running.

 

[5030]

When power is out, the only time im upset is when i cant hear my generator running.

I don't hear ours at all. Out next to the shop and diesel fired. Been running non stop for 6 days now, it's a mess here. Got a load of trees to cut up Only time I shut it off is to check the fluid levels every 2 days. It's a Generac 20 KW with a JD 3 cylinder turbo charged diesel and it's enclosed and very quiet. Bought it about 15 years ago and has been flawless. Been through about 100 gallons of diesel so far. Plumbed to my 500 gallon bulk tank.

Hate to think what one costs today.

 

[coobie]

I don't hear ours at all. Out next to the shop and diesel fired. Been running non stop for 6 days now, it's a mess here. Got a load of trees to cut up Only time I shut it off is to check the fluid levels every 2 days. It's a Generac 20 KW with a JD 3 cylinder turbo charged diesel and it's enclosed and very quiet. Bought it about 15 years ago and has been flawless. Been through about 100 gallons of diesel so far. Plumbed to my 500 gallon bulk tank.

Hate to think what one costs today.

Love to see a pic of that 3 cyl.John Deere Diesel engine in your generac. You stories AMAZE me. I know they're $60,000 mobile units are JD engines.

 

[YanmarFever]

We have a Yanmar, 12kw, 3 cyl, diesel,1800 rpm unit, I've only had to use it 3 x in the last 11 years, but its very quiet and uses very little diesel.
It will run the A-C and half the house including the well pump. You can talk while standing next to it, its in a quiet insulated metal box.
We are really happy with it, its never failed us yet.

 

[5030]

Love to see a pic of that 3 cyl.John Deere Diesel engine in your generac. You stories AMAZE me. I know they're $60,000 mobile units are JD engines.

Your perpetual hard on for me also amazes me. I don't do pictures for your entertainment. Pulled the paperwork for it out of the file. 15 years ago, I paid 9 grand for it and an additional 1500 for an authorized Generac dealer/installer to install it as electricity and I don't get along well. I did do the physical (fuel hookup) and had the local concrete company pour a pad. for it. Bought it from Norwall Systems btw.

Running presently as we still have no utility power. Do have Internet however. Hoping today they (utility company DTE) gets us back online.

Had a large branch come down and pulled the feed off the pole out front. Weatherhead is intact and the line is laying next to the driveway. Kind of surprised it didn't snap off the pole, but it didn't.

Have a huge mess to clean up, 3 large trees met their demise. You can come over and help if you can get out of your recliner and do something useful, which I doubt.

Glad I had a private contractor (tree company) clear the rights of way on the rentals, everything intact on them, just no utility power.

Just another day in paradise.

 

[nyone]

I think that power companies can easily get complacent with tree trimming then you have a storm, nothing special just the right combination of snow, ice with a little wind and thousands of homes are out of power. The media blows this out of proportion and of course the residents are not used to this either and the frenzy grows. Urban areas are the worst, their idea of being prepared is to have their "devices" charged!

Why would they bother trimming trees when mother nature can do it for them, then they can collect state/federal aid?

 

[5030]

Why would they bother trimming trees when mother nature can do it for them, then they can collect state/federal aid?

Don't think that is gonna happen at least here.

 

[newbury]

Urban areas are the worst, their idea of being prepared is to have their "devices" charged!

One of my prime idea of being prepared is to have my "devices" charged.
I've a DeWalt FLEXVOLT Power Station and a bunch of batteries. With everything charged I can outlast most power outages without firing up my generator.

 

[WranglerX]

So much snow right now, it muffles the sounds of generators.... IN California's Sierra Nevada foothills, we usually get 2-3 inches of snow any winter in my location, in last 4-5 days 12-18 inches and still coming down.... Our UTILITY company is unable to even keep up with its failures and we have been out of electricity for approximately 3 days of the 4-5 day of this storm (yes we have a generator).... And our great Governor of Kommunist California what's to ban small gas engines, in mowers, chainsaw, and yard equipment and GENERATORS....

 

[coobie]

Your perpetual hard on for me also amazes me. I don't do pictures for your entertainment. Pulled the paperwork for it out of the file. 15 years ago, I paid 9 grand for it and an additional 1500 for an authorized Generac dealer/installer to install it as electricity and I don't get along well. I did do the physical (fuel hookup) and had the local concrete company pour a pad. for it. Bought it from Norwall Systems btw.

Running presently as we still have no utility power. Do have Internet however. Hoping today they (utility company DTE) gets us back online.

Had a large branch come down and pulled the feed off the pole out front. Weatherhead is intact and the line is laying next to the driveway. Kind of surprised it didn't snap off the pole, but it didn't.

Have a huge mess to clean up, 3 large trees met their demise. You can come over and help if you can get out of your recliner and do something useful, which I doubt.

Glad I had a private contractor (tree company) clear the rights of way on the rentals, everything intact on them, just no utility power.

Just another day in paradise.

5030 not a hard on for you at all.I just don't like folks like yourself that just FLING false information on many subjects with no merit to the good folks on this site that need it.Take care and remember your medical checkup this year. On a side note I also have a 12 year old generac whole house(propane)17kw 2 CLY. gas motor I could not afford that big old diesel pusher you bought.

 

[5030]

Your perpetual hard on for me also amazes me. I don't do pictures for your entertainment. Pulled the paperwork for it out of the file. 15 years ago, I paid 9 grand for it and an additional 1500 for an authorized Generac dealer/installer to install it as electricity and I don't get along well. I did do the physical (fuel hookup) and had the local concrete company pour a pad. for it. Bought it from Norwall Systems btw.

Running presently as we still have no utility power. Do have Internet however. Hoping today they (utility company DTE) gets us back online.

Had a large branch come down and pulled the feed off the pole out front. Weatherhead is intact and the line is laying next to the driveway. Kind of surprised it didn't snap off the pole, but it didn't.

Have a huge mess to clean up, 3 large trees met their demise. You can come over and help if you can get out of your recliner and do something useful, which I doubt.

Glad I had a private contractor (tree company) clear the rights of way on the rentals, everything intact on them, just no utility power.

Just another day in paradise.

Why I keep you on ignore (only one btw) so I don't have to read your drivel. You never have anything positive to say and I'm glad I'm not you, you must lead a very sorry existence.