generator question

[speedsport]

After the recent ice storm here in Oklahoma I went wothout power for 9 days, ain't gonna happen again. I am looking at a GENERAC UltraSource 15Kw generator, and a natural gas conversion kit, 15kw continous 22.5kw surge. Advertised as being made in USA, Wisconsin. Anybody have any experience with this company's product?

[timcasbolt]

No experience with that brand, although I have an Onan about that size that I'm very satisfied with. Highly recommended.

[IOWOLF]

Are they still making the Onan?Can you get parts?

[Herm Williams]

onan is owned by cummins diesel, I recently repaired a generac generator had to rewind the armature, had a mitzibishi (sp?) three cylinder diesel engine. During test it did put out rated power with no problems. I believe the generator is made in the US but the engines I've seen may not be.
re

[wierdscience]

I know several people who have them,they are good units,but if you run one for several days or a week be prepared for a huge gas bill come the end of the month.
I did also know one guy that had one during Katrina,it worked flawlessly until a tree uprooted down the street and took out the city gas line:(

Me I am going diesel,either a stand alone unit or a pto tractor driven model,diesel is more effecient and can be stored a long time.

[jmm360]

Speedsport,
I don't know that product but I've lived off generators quite a bit. For your basic living needs- fridge, freezer, furnace, lights,radio- 5 kw is probably plenty in a storm type outage.
If you have to keep a shop running that could go way up.

The transfer switch issue has been beaten to death, I'll just say if you get one you won't regret it.

If I was doing it over I'd go Honda for quiet, or whisperwatt for quiet with more kw.

Good luck,
John

[Dick Plasencia]

How large a KW rating would be needed to run the average kitchen refrigerator. I'm only interested in keeping the refrigerator cold enough so the contents don't spoil. Probably run it 3 or 4 hours per day about one hour at a time while the power is out. Don't need power for the rest of the house. Got oil lamps and a gas stove.

[Your Old Dog]

Think it's safe to say 95% of all the TV live trucks in the country are Onan powered. We run them about 1 1/2 to 2 1/2 hours for the AM, Noon, 5PM, 6PM and 11PM news cast. We run not only the editing equuipment but the Air Conditioner and electric furnace in the winter. If they get maintained they last damn near forever. In the past 15 years of that kind of service for 3 live trucks I only recall 3 times when the motors had to be pulled for major repairs.....but they weren't replaced except for new trucks about every 10 years.

I have a 7KW Generac electric start gas powered unit and it serves our purposes just fine for power outages. We make some effort to cut back and don't run every light in the house. We run the well, frig, freezer, microwave, furnace and blower on the wood stove as well as a few lights here and there. I charge batteries while the gen set is running for flashlights and such. If I did it again I'd like a Nat Gas powered kw unit and the hell with the gas bill. If it ran a month that might happen once in a life time. For the comfort it is worth it.

I don't have the automatic switchover and it's no big deal for me BUT ADMIT it would be a lot easier for the wife if we did.

[oldtiffie]

I don't have a need for an alternator - as yet - for "Mains" power alternative.

I have had some comment and read that the output of some alternators is or may not be suitable or ideal for some "stuff" - computers, control/security devices and some domestic appliances or "stuff" in the "shop".

Any comment/advice would be appreciated.

[darryl]

I've had this discussion many times with a friend. What we came down to was a 5 or 6 kw model being about optimum. You can dry clothes and run the fridge and a few lights, or a microwave and the fridge and some lights, or an electric heater, even two, and the fridge and some lights. You can't dry clothes and run two electric heaters and lights and the fridge at the same time, but you can save a few bucks on the gas bill by not asking for too much luxury during these temporary times. We based these calculations using a figure of 3000 watts for the dryer.

[wierdscience]

I've had this discussion many times with a friend. What we came down to was a 5 or 6 kw model being about optimum. You can dry clothes and run the fridge and a few lights, or a microwave and the fridge and some lights, or an electric heater, even two, and the fridge and some lights. You can't dry clothes and run two electric heaters and lights and the fridge at the same time, but you can save a few bucks on the gas bill by not asking for too much luxury during these temporary times. We based these calculations using a figure of 3000 watts for the dryer.

Darryl,watch those clothes dryers,electrics average 5800 watts running load with an additonal 1800 for starting for a total of 7600 watts starting.It's the cold element load that does it.A gas dryer on the otherhand only needs 600 watts startting since it's just running a timer and a 1/4hp motor.

I ran lights,fans,washer and gas dryer all at once of a 5k after Katrina with no problems.What made it cough was a 1200 watt hair dryer,switched on by itself it opened the governor up on the genset and made the valves rattle for a couple seconds until the element warmed up:D

[A.K. Boomer]

S.S. We just started dealing them, iv installed a few and they seem good quality --- I repaired one circuit board (replaced actually) because it totally fried a circuit, but the system was installed for a very pricey house way on top of a hill -- I think it got zapped by lightening, (very pricey house -- this guy also owns a 4wd 12 cyl. Lambo gallardo and a twin turbo noble)

Dont know about the 15 Kw in particular, but Generac is not all US I know for sure -- I know I seen one US and a different model (I think smaller unit) that the engine was actually - you got it - china...

They got a strange way of adjusting frequency but besides that I dont mind the mechanical layout and design.

[franco]

Dick Placencia,

During the power outage after the last cyclone here a couple of years ago we used a 1800W intermittent / 1500w continuous rated 240V Chinese generator to keep the domestic refrigerator and deep freeze cold. We swapped it between the two appliances, running each one for about three hours at a time for a total of about 15 hours per day. It had no problem with starting either machine after a three hour break, and once the appliance was started we could run a few lights, a couple of fans, an analogue TV and battery chargers for flashlights etc. as well. I did not try starting the second appliance while the other one was running - thought this might have been stretching my luck a bit. Had the slightly larger 2800/2500 model been available at the time I would have bought it for preference, but the smaller generator handled the load OK. It ran about 15 hours a day for three days without any fuss, and used about a litre of petrol an hour.

I had been a bit doubtful about buying a Chinese generator, but it was all that was immediately available at the time, was about half the price of an equivalent Honda powered unit had one been available, and it proved to be quite OK for the purpose. The generator cost about half the replacement cost of the food which would have been lost if it had not been available.

franco

[CCWKen]

One thing for sure; You can't go by what others are using as far as capacity. You need to determine what you are willing to do without and/or what is necessary to sustain life. If you're in an all electric home, your needs may be different from someone that lives across the street and uses gas or LPG for cooking. Your needs may be different if your home includes very young or very old or someone that needs special equipment. Your location plays a big part in needs. In deep South Texas, summer air conditioning is more important than most winter heat. If it's 105 outside it's going to be 120 inside a house without air. Add the usual humidity and heat factors become deadly. Summer also places a heavier load on refrigerators and freezers. Also, don't forget sump pumps and water pumps.

Determine the basic needs of YOUR household and add about 10-25% more capacity so the generator isn't running at full load just for necessities. You could be supporting relatives or neighbors in an emergency.

[darryl]

Thanks, WS. I should have added that it is important to check the ratings before adding things up- also the starting draw being higher than the running draw. Our dryer is rated at 3200 watts, IIRC, and we just used that figure as is.

Sizing a generator could be like machines- get one and suddenly it's too small. Maybe it is better to put on that fudge factor after adding up all the loads you'd possibly be wanting to run at once. As pointed out, it's only odd occasions where you'd be using it as an emergency generator, and the extra fuel a larger unit would eat doesn't count for much in the long run. Still though, it would be nice to be able to run longer on the same amount of fuel.

Very much a decision for the individual to make, as also pointed out.

[speedsport]

I am selfish, I don't want to give up anything, I want life to continue un-interupted and I believe that 15kw continous will do it. After seeing the long lines at the places that sell gas I decided that NG would eliminate that hassle. Thanks for the replies.

[cadwiz]

I bought the Generac Ultrasource 15kw between Katrina and Rita. So far haven't needed to run it for real. Load testing hasn't bogged it down. The one I got came with a transfer switch. I set up an Excel spreadsheet and configured all the circuits of interest including starting surge. The analysis says I can selectively run my entire house with judicial load balancing. The generator itself is rather loud. I'm working on a muffler change now to fix that. The biggest issue is gas supply. I can store up to around 100 gal of gas but really don't want to. I've already made plans to convert to propane and install a tank. This is one investment I don't regret.

Cadwiz

[Dick Plasencia]

My question on generator size goes to the optimum machine to have. Too big a unit is a waste of assets and fuel and too small will not do the job. My problem is I can't seem to find anywhere information on the starting surge of the refrigeration machinery in a common household refrigerator. I do know that most refrigerators will draw under 200 watts when running but that start up is a killer because I see the lights blink in the kitchen when the compressor kicks in. The other item that needs power would be the furnace during winter. That is easily accounded for because the 1/2 HP fan is all that draws any real power in a gas furnace. So how big a generator is needed to get a refrigerator off and running?

[aboard_epsilon]

if i was to do that

i would do it with one of those Indian listeroid ones ...
these run on ...diesel ..kerosene ...waste veg oil ...and even old (filtered)engine oil ...so Ive heard ...
one of these perhaps running a 6 hp gen set .....

plus a bank of batteries ....enough to give out 30 kw at max

and 7.5 kw for a few hours.

(don't know how many batts that entails)

some sort of electronics that turns it off when all the batteries are charged ..

so it would be running flat out at max efficiency .....maybe only a few hours a day .....

you can also ...pipe the coolant to your central heating system and hot water supply.

if only i lived in some secluded spot were i could get away with this ..i would be one happy man ...

all the best.markj

[Weston Bye]

To add my own anecdotal experience:
For the last nearly 20 years I have used a Honda 3500W 120/230V generator. I consider this the absolute minimum necessary. I needed the 230V for the well pump, and the additional benefit was that I could backfeed both sides of my breaker panel 120V. This made it convenient for load sequencing, as I had deliberately placed the refrigerator and freezer on dedicated breakers when I built the houses.

My load sequencing always allowed all the lighting and furnace to be used, but I had to shut off the refrigerator and freezer to run the pump. Surprisingly, I could run the pump, washer and dryer all at once, along with the furnace and lighting.

The microwave was even possible with all the big loads off.

As long as I stay home to manage the power, life goes on pretty normal for my family.

The Honda Generator still starts and runs well with no oil consumption after almost 20 years of sporadic outages, at least one a year, from a few hours to days, and long days of construction tool use when we built the second house. Worth the money.

[Willy]

My question on generator size goes to the optimum machine to have. Too big a unit is a waste of assets and fuel and too small will not do the job. My problem is I can't seem to find anywhere information on the starting surge of the refrigeration machinery in a common household refrigerator. I do know that most refrigerators will draw under 200 watts when running but that start up is a killer because I see the lights blink in the kitchen when the compressor kicks in. The other item that needs power would be the furnace during winter. That is easily accounded for because the 1/2 HP fan is all that draws any real power in a gas furnace. So how big a generator is needed to get a refrigerator off and running?

Dick have a look here (http://www.yamaha-motor.com/outdoor/generator/sizing.aspx).

[snowman]

For those of you working on Propane or NG systems...are the generators you are using employing garretson regulators?

I am having a little bit of difficulty understanding how the RPM governor works, is it simply the increased vacuum of the engine under load that is "sucking more" fuel from the regulator??

[Weston Bye]

Dick have a look here (http://www.yamaha-motor.com/outdoor/generator/sizing.aspx).

Hmmm... My mileage did indeed vary, as the numbers presented say that I should have been tripping the breaker regularly. Maybe the Honda was better than average?

[Willy]

As they say, your mileage may vary. I think as you say, keeping close tabs on what you are using and load balancing are key to getting the most out of your genny. I do the same as you as far as load sequencing goes, I'm sure if somebody not familiar with the system were to step in...the breakers would be a poppin! A little common sense goes a long way.

Having said that, I did notice a Chinese 4000 watt generator on sale the other day for a little over $300.00. After looking at the generator head itself, all I can say is that it looked like a coffee can compared to a quality unit. Like comparing a 150 amp large truck alternator to a 150 amp mini van alternator.

[aboard_epsilon]

For those of you working on Propane or NG systems...are the generators you are using employing garretson regulators?

I am having a little bit of difficulty understanding how the RPM governor works, is it simply the increased vacuum of the engine under load that is "sucking more" fuel from the regulator??

its some sort of thing attached to the fly wheel that spins out and thru a weighted linkage just puts more throttle on, when it bogs down under load.

all the best.markj

[J.Ramsey]

Most small engines use a centrifugal governor,usually camshaft mounted.

[darryl]

Somewhat intrigued about the power draw of a fridge, I decided to check mine out. Nowhere did I find any ratings, and this seems odd to me.
But looking at it another way- I have yet to see a compressor that 'looked' to be more than about 1/2 horse, by comparing the size of the actual motor. Even a large fridge probably doesn't use a motor larger than maybe 1 horse. If you want to build in a fudge factor, it would probably be safe to say that at most it would draw 1500 watts, and when running call it 1000 watts.

Yes, definitely check your ratings, and if any confusion exists, post the specs here and we'll figure it out. I think it would be interesting for some of us at least to see what the various units are drawing power-wise.

[wierdscience]

For those of you working on Propane or NG systems...are the generators you are using employing garretson regulators?

I am having a little bit of difficulty understanding how the RPM governor works, is it simply the increased vacuum of the engine under load that is "sucking more" fuel from the regulator??

Flyweight governor driven off either the cam or crank pulley.Diesel also uses a flyweight governor,but it is built into the injection pump and acts directly on the fuel rack.

A quick check with a 110vac clock and a stop watch will tell you if your genset is producing 60hertz or not.

[wierdscience]

We have an old one of these gensets at work.This is what I would like to have,has anybody seen one in one of HF's stores?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45381

[Mad Scientist]

Measured the current on brand new freezer at 2 amps. Old dinosaur freezer uses 5 amps. An old refrigerator draws 3 amp.

Bought a Harbor Freight generator head (7500W continues & 10,000w peak) last summer on sale for $300. Then bought $150 car for its engine to run it. Uses about a gallon of fuel per hour. Fuel use obviously varies with load. The 10,000 Watt peak rating insures that I can start just about any load.

[A.K. Boomer]

Iv seen those HF generator heads your talking about, actually dont look harbor freight at all -- very nice looking quality.

[Deja Vu]

Measured the current on brand new freezer at 2 amps. Old dinosaur freezer uses 5 amps. An old refrigerator draws 3 amp.

Bought a Harbor Freight generator head (7500W continues & 10,000w peak) last summer on sale for $300. Then bought $150 car for its engine to run it. Uses about a gallon of fuel per hour.

..don't have a generator yet, but any signs of unstable power around here and I'll make it a priority! i've been for years eyeing the potential deals around. Harbor freight carries most of what I use here, so your approach agrees with me. :D

I've always been justifiying them since enjoying their versatility when installing modular homes in earlier years. Yup, for a home(or business) susceptible to frequent and inconvenient outages of both gas and electricity a 7500W would bring a lifestyle to moderate changes if there is an emergency electric waterheater installed (for the northern area :)

John Bloy

[wierdscience]

[QUOTE=Deja Vu
I've always been justifiying them since enjoying their versatility when installing modular homes in earlier years. Yup, for a home(or business) susceptible to frequent and inconvenient outages of both gas and electricity a 7500W would bring a lifestyle to moderate changes if there is an emergency electric waterheater installed (for the northern area :)

John Bloy[/QUOTE]

Water cooled gensets have hot water as a usable byproduct;)

[wierdscience]

Heard good things about these,simple and built like a brick s---house.

http://cgi.ebay.com/15KW-ST-Generator-Head-1-Phase-for-Diesel-Gas-Engine_W0QQitemZ330199254530QQihZ014QQcategoryZ106 437QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Deja Vu]

Water cooled gensets have hot water as a usable byproduct;)

heh! I'll put that on the list for features required on the future gen purchased (or possibly traded for).

[true temper]

My mother decided she wanted a generator, I ordered a 15kw Briggs and Stratton from Northern tools. She was sure glad she had it power was off for 4 days. It is a package deal with whole house auto transfer switch. Runs on natural gas, when power goes off it starts its self and switches automaticly. It exercises its self for 15 minutes once a week.

[Your Old Dog]

Iv seen those HF generator heads your talking about, actually dont look harbor freight at all -- very nice looking quality.

I was looking at one last week and that was my exact thought. Looked pretty well made to me.

[Dick Plasencia]

Thanks for the Yamaha chart on power requirements. 2200 watts starting surge sounds reasonable for a refrigerator. I'm estimating the start load on the way the lights dim momentarily as compared with our vacuum cleaner that draws 12.6 amps. So based on this a 2.5 KW generator with some surge capability should do the trick for me. I do know that refrigerator motors are usually around 1/6 HP. Not much power is required but the problem is the motor is sometimes commanded to start against a gas pressure load. Most of the time the gas equalizes on the input and output sides of the compressor but if the thermostat is reset colder the compressor will re start and the start load goes out of sight.

[gunbuilder]

Hello to the group,
I will chime in on this one.
After the ice storm of Thanksgiving weekend 2005, my standby power plant was worth it's weight in gold (almost). I have a 1600 watt Coleman, it ran the furnace or refrigerator with a few lights just fine. It didn't run the deep freeze, not at all. I even ran a cord direct to the Coleman, still would start the large chest freezer. I now have my Coleman and a 5000 Watt unit (can't remember the make).

As far as running electronic devices or computers off standby power, I say sure as long as they have a ups (uninterruptible power supply) in line.

I, too have a 10KW gen head from HF, I just haven't gotten it hooked up to the tractor PTO or to the diesel engine I bought for it.
Thanks,
Paul

[oldtiffie]

..........................
............................
As far as running electronic devices or computers off standby power, I say sure as long as they have a ups (uninterruptible power supply) in line.
................................
.................................

Paul

Thanks Paul.

I don't anticipate a long-ish power outage more than a couple of hours - who does, until it happens - as we are pretty well provided for in OZ.

I thought I'd ask - just in case.

I have been looking at some smaller gen-sets (1.5>2 KW) for occasional use away from the power at the house.

I've seen Building Contractors etc. use them and they are very keen on them.

The question re. UPS is quite relevant here though.

I have three small and medium-sized APS UPS's but they are a "battery back-up unit". That is to say that they monitor the power supply and filter it (phone line too) and only "switch-in" if the power supply (voltage?) goes above or below a set range or when the power supply fails. It is when the power supply fails that the UPS acts as an inverter and uses its battery to produce the 230-240v 50~ AC supply to the computer.

It seems to me that the UPS that I have may not filter or correct the frequency or wave-form in any way. That is to say, as it might be if it were on with a gen-set.

How stable is the voltage and frequency on a gen-set?

Our power supply does fail occasionally.

When this happens, the UPS "kicks in" every time and keeps the computers running until either I shut them off or the "auto-shut-down" software kicks in.

I have run the computer while on UPS supply and there was no problem at all.

There was an occasion where the mains supply fluctuated and failed and returned several times in the space of a couple of hours and the UPS functioned flawlessly - very pleased and very relieved.

It worked a treat when we had a couple of "near misses"with lightening strikes as well.

[Mad Scientist]

How stable is the voltage and frequency on a gen-set?


They are not. Frequency is direct related to the RPM of the generator. For example the HF generator must run at exactly 3600 RPM to make 60 cycles.



I have run the computer while on UPS supply and there was no problem at all.

If a UPS supply is running off its battery the output frequency should be pretty close to the correct line frequency.
If it is running off the line it will more then likely pass threw whatever the line frequency happens to be.

A few cycle + or – from the ideal frequency will not harm anything. Unless of course you need an accurate time base to run something like an electric clock.

[oldtiffie]

They are not. Frequency is direct related to the RPM of the generator. For example the HF generator must run at exactly 3600 RPM to make 60 cycles.

If a UPS supply is running off its battery the output frequency should be pretty close to the correct line frequency.
If it is running off the line it will more then likely pass threw whatever the line frequency happens to be.

A few cycle + or – from the ideal frequency will not harm anything. Unless of course you need an accurate time base to run something like an electric clock.

Thanks MS - most informative.

I guessed at that being how it was but really didn't know.

I do now though.

[Bob Ford]

Oldtiffie

I have a Honda EU 3000 inverter generator. These are quite and will run electronics. This is the Australian link.

http://www.hondampe.com.au/wps/wcm/connect/hondampe/Home/Power+Equipment/Product+Range/Generators/Commercial/EU30is/

Bob

[jdunmyer]

Some UPSs will not like the power from some gensets and will refuse to connect to the "line" when powered from a those gensets.

A 15Kw outfit should run most everything in most homes, with only a bit of load management for things like electric dryers, stoves, or A/C.

A buddy has one of those 15Kw Generac gensets, fueled from his 500-gallon propane tank. It runs for 10 or 15 minutes, every week, and automatically switchs on upon a power outage, then flips the transfer switch to power the house. He loves it.

Mine is a bit more crude and manual in operation:

http://www.oldengine.org/members/jdunmyer/genset

Works great!

[Roy Andrews]

you guys are pathetic. buy another tool! i have a 10kw miller gas drive welder that i have used many times to run my whole house and i get to weld with it to (including MIG in the field with a suit case).:D

[speedsport]

Roy,
Has the thought that maybe everyone can't afford the same things that you can ever crossed yourmind? can you say "fixed income"?., pathetic is a very mean word.

[wierdscience]

Ya,most folks don't have $3800 laying around doing nothing:D