# Not a Stihl but maybe a basic question



## dajain (Jul 29, 2021)

I am looking at a 25 KVA generator on an online auction. Shows a video of the motor running and the generator putting out a solid 60 hz. Problem is, the AC volt gauge stays on Zero.

The don't have a load on the unit. Just wet staking the engine.

Question is, will a generator create hertz without producing voltage? My logic of generators says if you have one coming from the stator/rotor, you should have both.

Already have a bid on the unit, can't inspect due to distance.

Thanks in advance


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## iowagold (Jan 22, 2020)

that is a great question!
it all depends on how the hz sensor is placed on the gen set.
what is the auction link? or at least the make and model of the gen set.
they could to have had the breaker tripped out for the output volts?
some of the volt meters are after the main breaker.
or the voltage selector.


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## dajain (Jul 29, 2021)

Here is the link. Surplus Power Gard 25 kVA Mobile Gen Set in Jal, New Mexico, United States (GovPlanet Item #5276756) 

I won the auction and called the owner. The unit does generate power and they have used it at their job sites. Of course you can't contact the seller until the item is bought and paid for.

I didn't think about the voltage gauge being hooked up after the disconnect. 

It's 800 miles from me so we'll find out for sure after I pick it up on Monday.


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## FlyFisher (Jun 30, 2018)

dajain said:


> It's 800 miles from me so we'll find out for sure after I pick it up on Monday.


You got me beat. I thought I drove far when I went 150 miles to pick up a unit... 

In any event, good luck to ya. At that distance it had to have been a good buy to make the trek.


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## dajain (Jul 29, 2021)

It's all relative I Guess. haha
I live in the middle of nowhere. The nearest auto parts store is 55 miles and the nearest Walmart and/or Hospital is 125 miles away, each direction.

800 miles is just a little day drive. Hope the thing is worth it with that many hours on her.


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## dajain (Jul 29, 2021)

It's all relative I Guess. haha
I live in the middle of nowhere. The nearest auto parts store is 55 miles and the nearest Walmart and/or Hospital is 125 miles away, each direction.

800 miles is just a little day drive. Hope the thing is worth it with that many hours on her.


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## drmerdp (Apr 10, 2018)

Holy moly, 25,000 hours, I’ve only seen a skid steer with anything close to that many hours on it lol.


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## dajain (Jul 29, 2021)

drmerdp said:


> Holy moly, 25,000 hours, I’ve only seen a skid steer with anything close to that many hours on it lol.


Yup, it has a lot of hours and that is probably why there weren't any other bidders. 

But if you look at the numbers on the oil analysis, the PPM's on all the bad stuff (Tin, Aluminum, Iron, etc.) is actually below the moderate allowable ppm's for a diesel engine. That is why the engine hours really didn't bother me and I bid on it.

Keep in mind that this is going to be our standby generator for the entire farm. It will get a nice retirement home with synthetic blend 25W40 marine oil, regular servicing, and less than 200 run hours per year. Another reason why I was looking for cheap.


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## iowagold (Jan 22, 2020)

dajain said:


> Here is the link. Surplus Power Gard 25 kVA Mobile Gen Set in Jal, New Mexico, United States (GovPlanet Item #5276756)
> 
> I won the auction and called the owner. The unit does generate power and they have used it at their job sites. Of course you can't contact the seller until the item is bought and paid for.
> 
> ...


wow on the hours!
that is like 1,474,920 miles on a car.
it would to have been a hard pass for me.
unless the hours are not right.

i would re gauge the unit, all new outlets, new battery, total check out before connection to any equipment with a load bank.

i would look at the diesel engine as well....
it is at rebuild time on most brands of diesel engines.
exchange cost for an crate engine would be $7000.00 to $10,000.00...
but if you are a diesel repair guy you can rebuild one for $5k in parts.


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## dajain (Jul 29, 2021)

iowagold said:


> wow on the hours!
> that is like 1,474,920 miles on a car.
> it would to have been a hard pass for me.
> unless the hours are not right.
> ...


My service truck that I use for 100% of my business dealings has 1.22 million miles on it and it's not even a diesel. Yes..... That is 1,22x,xxx miles on a 1 ton gasser service truck. lol
Hours and miles are just numbers. The oil analysis numbers show this to be a healthy engine. I will trust those before I trust that gauge.
I am a mechanic by trade, run a repair shop and I am also MSHA (Mine Safety & Health Admin.) certified electrician for both surface, underground and explosive atmospheres. 
I think I have my bases covered. haha

But the hours of the unit are not what are in question. I knew what they were when I bought it. 
It's coming here to be a back up and live an easy life of maybe 200 hours a year. 
Yes, a full service/fluid flush will be in order and the electrical plugs won't be used. It will be hard hired.
The battery will get tested and if still good, will remain in the unit but a solar panel to keep charged will be installed. Nothing worse than a dead battery when you want it to start. If it tests bad, it will be replaced.

Besides, I already have the trailer sold for $800 and if this goes bad, I can buy a motor with half the hours for $2000 or the generator end will produce enough recycled copper to make up the difference then buy a generator end at the same auction for $150. Either way, it still beats paying $6000 for one that has 10,000 hours.

Thanks for the concern though.

Back to the original topic though, I've never seen a generator put out hertz without voltage. Is this even possible?


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## tabora (Sep 6, 2018)

dajain said:


> Back to the original topic though, I've never seen a generator put out hertz without voltage. Is this even possible?


A generator does not "put out hertz". It outputs Alternating Current at a particular voltage and hertz, typically either 60Hz or 50Hz. Non-inverter generators create A/C at 60Hz by running at 3600RPM with a 2-pole stator or 1800RPM with a 4-pole stator.

This diagram shows 1Hz (one cycle), i.e. 1/60 of a second of a 120V nominal voltage wave.


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## dajain (Jul 29, 2021)

tabora said:


> A generator does not "put out hertz". It outputs Alternating Current at a particular voltage and hertz, typically either 60Hz or 50Hz. Non-inverter generators create A/C at 60Hz by running at 3600RPM with a 2-pole stator or 1800RPM with a 4-pole stator.
> 
> This diagram shows 1Hz (one cycle), i.e. 1/60 of a second of a 120V nominal voltage wave.
> 
> View attachment 9796


If the generator is not spinning there is no measurement of hertz so, yes, the generator does produce and puts out hertz. It is a form of measurement just like VAC and it is produced by the rotation speed of the rotor. You can change the speed of ANY generator to make either 50 or 60 hertz but your voltages will be completely off if you do.

In case you missed it, I am a MSHA certified electrician and have dealt with 12 VDC control circuits to love 13.8 KV power transmissions. This diagram is studied the first day of the certification process. 

Thanks for sharing though.


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## tabora (Sep 6, 2018)

dajain said:


> If the generator is not spinning there is no measurement of hertz so, yes, the generator does produce and puts out hertz.


Not to beat a dead horse, but Hertz is not a "thing", but rather a characteristic of a thing. Hertz, in short Hz, is the basic unit of frequency of the vibration cycle time of electric, magnetic, acoustic and mechanical vibration, i.e. the number of times per second (cycle/sec) that resonance occurs. In the absence of the "thing", it has no characteristic of frequency which is therefore zero (or, I suppose, infinite).

Alternating current (AC) is changing the direction of the current periodically.
Cycle is the time of a cyclical change of the current.
Frequency is the times of the current changes per second, unit Hertz (Hz).
AC current direction changes 50 or 60 cycles per second, in accordance with 100 or 120 changes per second, then the frequency is 50 Hertz or 60 Hertz.


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## dajain (Jul 29, 2021)

tabora said:


> No to beat a dead horse, but Hertz is not a "thing", but rather a characteristic of a thing. Hertz, in short Hz, is the basic unit of frequency of the vibration cycle time of electric, magnetic, acoustic and mechanical vibration, i.e. the number of times per second (cycle/sec) that resonance occurs. In the absence of the "thing", it has no characteristic of frequency which is therefore zero (or, I suppose, infinite).
> 
> Alternating current (AC) is changing the direction of the current periodically.
> Cycle is the time of a cyclical change of the current.
> ...


And without the generator spinning, there is no Hz therefore it is something the generator creates and ultimately "puts out" unless you are saying that it magically appears due to the frequencies the motor generates while spinning the generator. That's a joke by the way.

The generator creates both the Alternating Current power AND the Hertz (aka wavelengths) at which the alternating current travels at. Without one, the other can't exist and therefore, both are put out by the generator in the purest definition. If it isn't something that isn't being produced and put out by the generator, there would be no need to measure it then, would there?

Both the VAC and Hz are products of a generator and used by the electrical devices plug into them. If hz is something that is not put out by the generator, then, in theory, it shouldn't matter if you plug a 60 hz device into a 50hz generator. Which that doesn't work very well.

Have a great day.


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## tabora (Sep 6, 2018)




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## JJ Ranch (Apr 23, 2021)

I've bought a few pieces of equipment from Iron Planet auctions and how they were represented in the description was quite accurate. Every now and then I window shop at GovtPlanet but no scores so far.


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## iowagold (Jan 22, 2020)

I would say you will find the old meters are bad on the gen set.


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## dajain (Jul 29, 2021)

iowagold said:


> I would say you will find the old meters are bad on the gen set.


With something with that many hours on it, it wouldn't surprise me. 
The listing even states the warning lights couldn't be tested.


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## dajain (Jul 29, 2021)

I find it hilarious that someone can not believe a generator "puts out" hertz. 

A generator, to be an effective generator, needs to "put out" or produce 3 things. 
1. Alternating current or VAC. 
2. Amperage. 
3. Hertz.

To say a generator doesn't "put out" hertz because it's a "frequency" is the same as saying a speaker doesn't "put out" sound because that is also a "frequency" but measured in Decibels.

All 3 components are measurable with instruments, are necessary for power generation and produced/generated/"put out" by the generator end of a unit. Period. Yes, all three thing as separate units, require separate measuring devices and all 3 have a different job in having sustainable power. To not "put out" one of these 3 components (including hertz), you have nothing but a paperweight.

Please stop using your brainpan to spread misinformation.


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## dajain (Jul 29, 2021)

JJ Ranch said:


> I've bought a few pieces of equipment from Iron Planet auctions and how they were represented in the description was quite accurate. Every now and then I window shop at GovtPlanet but no scores so far.


This is my first purchase from their auction site. I've been scanning the website for a while now and from what I have seen, their pictures seem pretty self explanatory but their written descriptions can be pretty vague sometimes and be missed quite easily.

Seeing this unit was probably an old rental, I wouldn't be surprised if the motor has been replace a time or 2 with that many hours. It's more cost effective to put a motor in than buy a new generator this size. Don't take that wrong, I'm not expecting it to be a replaced motor and I will treat it like it does have that many hours, but I can hope. haha
With the oil analysis numbers they show, I have a hard time believing it is that tired of an engine.


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## iowagold (Jan 22, 2020)

dajain said:


> This is my first purchase from their auction site. I've been scanning the website for a while now and from what I have seen, their pictures seem pretty self explanatory but their written descriptions can be pretty vague sometimes and be missed quite easily.
> 
> Seeing this unit was probably an old rental, I wouldn't be surprised if the motor has been replace a time or 2 with that many hours. It's more cost effective to put a motor in than buy a new generator this size. Don't take that wrong, I'm not expecting it to be a replaced motor and I will treat it like it does have that many hours, but I can hope. haha
> With the oil analysis numbers they show, I have a hard time believing it is that tired of an engine.


most of the good places when they place in a rebuilt motor the replace the hour meter then make notes in the inside of the chassis steel cover of the rebuild.

a total wow on the hours...
we do rebuilds at 10-20k hours.
or if they break down...
time chain, belts etc. injection pump and injectors.


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## dajain (Jul 29, 2021)

iowagold said:


> most of the good places when they place in a rebuilt motor the replace the hour meter then make notes in the inside of the chassis steel cover of the rebuild.
> 
> a total wow on the hours...
> we do rebuilds at 10-20k hours.
> ...


You are right, most "good" places will replace the meter when they replace a motor. Most mediocre places will use a sharpie next to the meter to make notes. haha

I lived down by Jal, NM for several years. For those not familiar, it is in the middle of oilfield country so who knows who would have have their hands on it. Another scary aspect of this unit. haha


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## dajain (Jul 29, 2021)

iowagold said:


> most of the good places when they place in a rebuilt motor the replace the hour meter then make notes in the inside of the chassis steel cover of the rebuild.
> 
> a total wow on the hours...
> we do rebuilds at 10-20k hours.
> ...


Once I actually have possession of the unit, I'll run the serial number on the motor and compare to the year of the entire unit. Maybe get more answers that way than anything else.


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## JJ Ranch (Apr 23, 2021)

Lots of Iron Planet equipment is rental - if it's painted green, that's a former Sun Belt rental.


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## iowagold (Jan 22, 2020)

cool!
does it start and run?


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## iowagold (Jan 22, 2020)

yea flush the engine, service it.
test run for a bit and drop an oil sample after 20 hours or so...
space heaters make a nice low cost load test....

do you have access to diesel test equipment??
might be cool to pull the injectors and compression test.....
and take a look at the injectors as well...
also check the fuel system for the bio diesel bug...

head gaskets are a known issue...
we change them every 5k to 10k hours
and clean the top end and inspect the cyl bore.
easy to do if you are into small diesel engine repair.
just a bit of time.
they need the valves set any way at those hours...
head gaskets are low cost
let me know if you need links for good parts for the engine.
we have a couple places here in the midwest we use for parts that are super fast shipping.

take your time and you might look in to digital upgrades on the meters!
easy to do that upgrade!


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## dajain (Jul 29, 2021)

JJ Ranch said:


> Lots of Iron Planet equipment is rental - if it's painted green, that's a former Sun Belt rental.


I was looking at some of the Sunbelt units and one this size usually goes for $3-6K. I figure this is either an old rental or just got shuffled around on a lease deal thru the "Franks Equipment" there in the area.


iowagold said:


> cool!
> does it start and run?


Yup, it runs and puts out power. That is actually what prompted the original post because the auction ad has a video of it running and it's putting out a steady 60 hz but the volt meter isn't moving.

After I paid for it, I called the owner and he verified it is a fully functional unit, just a lot of hours on the meter.
I'm headed down there today (800+ miles one way) and I'll see how she starts when she's cold (if you can call southern New Mexico that, haha) and that will tell me a lot about the engine. Hard start, soot, smoke (white or black) etc.

Hoping she's not an either addict. 

The oil sample they provided looks really good so fingers crossed. But will monitor that pretty closely due to the meter hours.


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## motormonkey (Jul 10, 2016)

dajain said:


> I find it hilarious that someone can not believe a generator "puts out" hertz.
> 
> A generator, to be an effective generator, needs to "put out" or produce 3 things.
> 1. Alternating current or VAC.
> ...


Your speaker analogy is faulty. The QUANTITY of electrical energy is measured in volts, amperes, watts, and perhaps joules. Frequency, or hertz, is NOT a quantity measurement, but a CHARACTERISTIC measurement. DC electricity has no "hertz," but it is nonetheless measurable energy.

Please stop using YOUR "brainpan" to spread misinformation.
Thread closed.


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