400hz gen sets able to do 60hz?

[Nonotagain]

The general rule of thumb is that for each 10KW of generator power, you're going to consume about one gallon of fuel per hour. So, you'll be sucking down roughly three gallons per hour with that 30 KW set whether it's loaded or not. Add to that oil changes at 100 hours - which are about the same as a car oil change given the size of the engine - and you're spending quite a bit on the larger set.

If you need that much power, so be it - just be aware what it's going to cost to run.

Another point; these are not like big-box store generators - an MEP-003A will put out 10KW 24/7 in all weather you're likely to throw at it, and is rated at somewhere between 100% and 300% overload for 30 seconds for starting motor loads (depends on who you ask). They are designed to run like this for thousands of hours before overhaul. An 8KW genset from the store is good for 8KW with a tailwind and your fingers crossed for a few full days of operation before it's pretty well worn out.

A 10KW genset will deliver 52A at 240V; use that for your planning purposes.

I ran a MEP-005 to power my old Mori Seiki 25 hp milling machine. The generator used 5.8 gallons per hour for the 1200 hours that I used it.

My local power company would not run 3 phase service to my garage, so I took matters into my own hands.

 

[goldneagle]

If you want to run everything you've got with the genset you can - but there's a price; whether you run a single light bulb or load the generator all the way to the maximum it does not change the fuel consumption per hour all that much, because you're paying to keep all the rotating mass in motion.

The general rule of thumb is that for each 10KW of generator power, you're going to consume about one gallon of fuel per hour. So, you'll be sucking down roughly three gallons per hour with that 30 KW set whether it's loaded or not. Add to that oil changes at 100 hours - which are about the same as a car oil change given the size of the engine - and you're spending quite a bit on the larger set.

If you need that much power, so be it - just be aware what it's going to cost to run.

Another point; these are not like big-box store generators - an MEP-003A will put out 10KW 24/7 in all weather you're likely to throw at it, and is rated at somewhere between 100% and 300% overload for 30 seconds for starting motor loads (depends on who you ask). They are designed to run like this for thousands of hours before overhaul. An 8KW genset from the store is good for 8KW with a tailwind and your fingers crossed for a few full days of operation before it's pretty well worn out.

A 10KW genset will deliver 52A at 240V; use that for your planning purposes.

Well then a 15kw unit will draw 1.5 gal/hr based on your figures. I am using a 4 cylinder engine from the 15kw military generator to run the 30kw + generator head. Does this mean the engine will consume double the rated gph? Also does that mean that if I only draw 15kw from the system I will not have the issue with sogging or whatever it was called since the motor is working to produce what it was rated at originally by the military?

 

[goldneagle]

I ran a MEP-005 to power my old Mori Seiki 25 hp milling machine. The generator used 5.8 gallons per hour for the 1200 hours that I used it.

My local power company would not run 3 phase service to my garage, so I took matters into my own hands.

Most electric companies will provide service in 3 phase to you location if you are willing to pay the cost of bringing it to that location. 5000 gallons of diesel is a lot of money! Did they ever quote you what it would cost?

 

[Isaac-1]

There are a lot of generalizations going on here, wet stacking is a real issue with all diesel engines, howver just how big of an issues depends on a number of factors of the individual engine design. Things like is it air cooled or water cooled, turbo charged, or not, as well as direct or indirect injected, compression ratios, etc. What is important in the case of a standby generator is that it is ran at full load for an hour or two every once in while to clear out the unburned fuel before the problem gets too bad.. Sure wet stacking will shorten the life of the engine, etc, but remember we are talking about units that are almost certainly going to get less than 500 hours of use per year, and in some cases that will be closer to 5 hours per year. We have a 30 year old 125KW standby unit at work that was bought off GL a couple of years ago, it just hit 600 hours on the meter a couple of weeks ago.

 

[Nonotagain]

Most electric companies will provide service in 3 phase to you location if you are willing to pay the cost of bringing it to that location. 5000 gallons of diesel is a lot of money! Did they ever quote you what it would cost?

The policy of the local power company is to not run 3 phase electric to residential areas. They are acting as the zoning cops in this case.

When I first started using the generator and mill, diesel/home heating oil was $1.50 a gallon. I could crank out a couple of hundred parts a 3-4 hour evening, so the cost was not a major concern. When diesel got to over $4.00 and the price of carbide end mills doubled, it was time to give up the shop.

My old boss had 480 3phase run to his garage many years ago. When the pole holding the transformers took a lightning strike they didn't want to replace the transformers due to the cost.

 

[KsM715]

Then add the 15 amps for the blower motor.

Your blower motor might be on a 15amp circuit but its not pulling anywhere near 15 amps. So goes for the rest of your circuits. You'd trip your main if you had every circuit maxed out at the same time. Add up all the breakers in your panel and youll find out that they far outnumber what your main is sized at.

 

[Chief_919]

You are trying to compare utility uses in NC to LA! I don't think so. My A/C runs about 9 Months out of the year! The rest of the time we are on heat pump. There is NO tank in a On demand water heater system! Ever have your wife do laundry and cook at the same time? Mine does all the time! Washer running, dryer running and hot water heater running (washer uses hot water). Those appliances do not need constant supervision - so you can cook while they run! We dod not have GAS in our block so everything is running on ELECTRIC.

Remember that I said I like to live in comfort and not have to be turning appliances on and off manually because the generator can't handle it.

I am also sure that next big power outage I will have the neighbors coming over to plug their extension cords for powering their fridges and freezers.

If you are happy with your 5 kw unit then enjoy. i tried after Gustav and it was lacking! No A/C and bare necessities! Boredom for days. Hard to sleep when the house is in the 80's with high humidity!

I hear what you are saying- but by planning for the highest possible amp draw scenario (and it looks like you are overestimating as well, going off the ratings for the circuits and not actual consumption), and not wanting to limit use when on the set, you are ending up running your genset the majority of the time at very low load (nobody is running hot water, cooking, or doing clothes all at once all night, or most of the day, for example).

That is bad for the generator.

For the price of not wanting to balance what appliances you use at once, you do need that big genset. My whole point is that by going oversize, you are running that genset the majority of the time at very low load, likely under 25%.

That will damage your genset.

If you are willing to risk damage and shorten the life of your generator so you don't have to wait until you finish cooking to run the dryer, then what you are doing makes sense.

My whole point was to point of that getting too much generator for the normal draw of the house is likely to end up shortening the life of the generator. As was said, how much damage it will do depends on a number of factors, but running the set like you are planning is going to wet stack it the majority of the time when it is at a low load, and that will damage it.

Myself? I would rather get a generator more properly sized for what the average draw is for the house, plus one peak draw- so I will simply wait to do the laundry after we finish cooking. And that way not risk wet stacking the genset and damaging it.

I deal with this all the time in my job with the Army. Every S3 thinks he needs a 60kw to run his TOC.......

 

[mikeroot2]

The policy of the local power company is to not run 3 phase electric to residential areas. They are acting as the zoning cops in this case.

When I first started using the generator and mill, diesel/home heating oil was $1.50 a gallon. I could crank out a couple of hundred parts a 3-4 hour evening, so the cost was not a major concern. When diesel got to over $4.00 and the price of carbide end mills doubled, it was time to give up the shop.

My old boss had 480 3phase run to his garage many years ago. When the pole holding the transformers took a lightning strike they didn't want to replace the transformers due to the cost.

Ronk makes Add-a-phase units to convert from single phase 230 to 3 phase 230. Ronk Electrical Phase Converters - Run 3 Phase Equipment On Single Phase Power. They have rotary units and capacitor units. You might want to check them out if this is still an issue.

 

[goldneagle]

Ronk makes Add-a-phase units to convert from single phase 230 to 3 phase 230. Ronk Electrical Phase Converters - Run 3 Phase Equipment On Single Phase Power. They have rotary units and capacitor units. You might want to check them out if this is still an issue.

The electronic units are not recommended! The rotary ones are much more efficient (over 80%). They are more expensive but are worth the extra cost on heavy equipment.

 

[Nonotagain]

Ronk makes Add-a-phase units to convert from single phase 230 to 3 phase 230. Ronk Electrical Phase Converters - Run 3 Phase Equipment On Single Phase Power. They have rotary units and capacitor units. You might want to check them out if this is still an issue.

I use a rotorary converter in the house to run my Bridgeport.

I looked at the phase converter route when I set the shop up. I needed to run a dedicated 100 amps to the garage for the converter in addition to the power for the lights and computers and AC unit.

When I weighed the cost of the electrical up grade and the converter, the generator was close in cost.

 

[goldneagle]

I know the load numbers I used are higher than actual. Circuit size is used to protect the wire from overheating. However they are in the ballpark! A 30 amp rated A/C unit uses more than 20 AMP to run..otherwise they would only use a 20 amp breaker. All appliance use is based on customer habits. Just because your wife may not wash cloths and cook at the same time doesn't mean mine wont.

I like what Icaac-1 said. Remember the engine on mine was designed to run a 15KW head. At 80% that is 12KW. So logically if I only pull 12KW continuously there will be no damage to the engine.

 

[Speddmon]

I wish we had the popcorn smiley back!!!!!!!!!!!!

 

[m16ty]

Ronk makes Add-a-phase units to convert from single phase 230 to 3 phase 230. Ronk Electrical Phase Converters - Run 3 Phase Equipment On Single Phase Power. They have rotary units and capacitor units. You might want to check them out if this is still an issue.

If you've got an old three phase motor, you can build a phase converter fairly easy.

 

[KsM715]

Speddmon, How come it took you 4 pages on a genset thread to show up.

 

[timntrucks]

that is funny

 

[Speddmon]

Speddmon, How come it took you 4 pages on a genset thread to show up.

I've been watchin it from the beginning. The first couple of posts answered the OP's question pretty well. Now I'm just enjoying the show over what an average size house requires for power consumption.

 

[ETBaals]

did anybody mention that , for example, a standard 5k, 40 amp has 2 legs of 110 each . so you only have 20 amps availible at a time, If you kick it up to 220 you are still at 20 amps.
The 400hz will work, if all you want to do is power lights.
A 3k for a house is mighty small, that is only 3000 amps.
Most motorhomes have a 5 amp.
A refridge or AC load start up can easlly over power a 3k or even a 5 k if there are other items on it.
For a gargage, you would want at least a 10KW maybe bigger, Our 5kw will not power our aircompressor when it restarts under load ( a 25 amp surge draw and the gen set only has 20 amps per leg)

I am a retired Onan service manager. 25 yearr experience
Ernie Baals


From Ernie Balls elder

 

[m16ty]

A 3k for a house is mighty small, that is only 3000 amps.

You could run a factory on 3000 amps.







I'm thinking you ment to say "watts".

 

[Isaac-1]

...
A refridge or AC load start up can easlly over power a 3k or even a 5 k if there are other items on it.
For a gargage, you would want at least a 10KW maybe bigger, Our 5kw will not power our aircompressor when it restarts under load ( a 25 amp surge draw and the gen set only has 20 amps per leg)

I am a retired Onan service manager. 25 yearr experience
Ernie Baals


From Ernie Balls elder

As I am sure you know a lot depends on the quality of the individual generator, I can tell you a MEP-701a 3kw (built by Onan by the way) has no problem starting and running a standard side by side refrigerator, a mid side chest freezer along with a 6500 btu and a 11,000 btu air conditioner along with a few CF light bulbs. Of course this is very conservatively rated generator and that 3KW is at .8PF at up to 8,000 ft and 120 degrees F (certainly not to be confused with the typical 3kw big box store generator). It may well also be the only 3KW generator on the planet that weighs in over 500 pounds. As mentioned earlier part of the post rebuild testing requires running at 200% load for 10 minutes.

Ike

 

[rat4spd]

All people are trying to say is that it is unwise to size a genset based on maximum peak alignment of the stars type loads. It is just impractical. For instance, I am a decent electrical hog. My usage last month was 3000 kWh's. If you average that, it's 4.2 kWh's average.

Sure, I drew 10, or 15 kw when everything cycled at the same time, but load calculations size your electrical service based on actual usage over a long period of time, not by the instantaneous maximum.

If you have a lot of resistive loads that cycle frequently, sure you need a larger genset. But to plan on your on demand water heater kicking on, and your central air cycling, along with your electric dryer running while your wife is using your electric stove is not realistic unless you plan on it happening constantly. Otherwise, you have a large unloaded genset running all the time.

This is called economy of scale. We, at the electric utility bear the burden of this economy of scale because even though we have a very large capacity, someone is always going to use it. With a genset hooked up to your house, you bear the burden of feeding a genset that inefficently uses fuel when it is unloaded just so that you can satisfy a load demand that happens maybe 5% of the time it is running.

But it is your money. I'm just explaining the flaw in your reasoning. Then again, we buy large inefficient MV's just because they are cool. YMMV.

I've been watchin it from the beginning. The first couple of posts answered the OP's question pretty well. Now I'm just enjoying the show over what an average size house requires for power consumption.