Stand By generator for shop?

[WhiffySpark]

I'm loooking at 11kw+ generators for a shop we may build. Anyone have experience in this? Think 11kw would be enough for lights, air compressors, etc. Just a typical garage 40x60 or so. Proppane or natural gas of course. Not fooling with gasoline.

Reason for the generator is I'm looking at buying 7 acres for a halfway decent price. We are going to build a shop for my business, but not build a house for a few years. Just to run electric out to the shop would be $10k from the pole. So I'm exploring some options to save money some money. Plus, once we build the house we could move the generator to the house as a back up power supply.

 

[drwheels]

I would watch Lowes for a return.I found one for a friend here while back on a good deal. Hope this helps.

 

[koditten]

Why not? As long as you are feeding the shop with a 100amp breaker, there is no reason not to.

Of course make sure that you have all the dedicated circuits in the house taken care of first.

I would make sure that you don't keep your compressor charged all the time. They do draw a heavy load when they start. the gennie might stall out if conditions were just right.

I chose not put my 100 amp shop feed on my 12k gennie. I leave my compressor charged 100% of the time. I spent too much on the gennie to abuse it with my shop compressor. I figure if the power is out for extended periods, I'm gonna enjoy a beer or 10 waiting for the power to come back.

Check with a sparky first to see if you can do this first.

as long as Momma has power, everyone is happy.

 

[koditten]

I don't think you are going to find many 12k + returns to Lowes. Anything that big is going to be permanantly affixed to the side of the home.

 

[WhiffySpark]

Why not? As long as you are feeding the shop with a 100amp breaker, there is no reason not to.

Of course make sure that you have all the dedicated circuits in the house taken care of first.

I would make sure that you don't keep your compressor charged all the time. They do draw a heavy load when they start. the gennie might stall out if conditions were just right.

I chose not put my 100 amp shop feed on my 12k gennie. I leave my compressor charged 100% of the time. I spent too much on the gennie to abuse it with my shop compressor. I figure if the power is out for extended periods, I'm gonna enjoy a beer or 10 waiting for the power to come back.

Check with a sparky first to see if you can do this first.

as long as Momma has power, everyone is happy.

That's what I was worried about was the cycling frying the generator

It'll be for a few years I assume before we build the house. I just don't want to put the cash out to have the power brought in from the pole until we're living there.

 

[larry_g]

Not knowing all your requirements but if your going to have land, you might want a tractor, so have you considered a PTO driven generator?

http://www.electricgeneratorsdirect.com/power/6-15-kw-540-rpm-pto-generators.html

lg
no neat sig line

 

[koditten]

Not knowing all your requirements but if your going to have land, you might want a tractor, so have you considered a PTO driven generator?

http://www.electricgeneratorsdirect.com/power/6-15-kw-540-rpm-pto-generators.html

lg
no neat sig line

I did the portable gennie thing for years. Once Mamma said we should think about getting a fixed unit, I couldn't go shopping fast enough.

I work shift work. I have no worries that the wife will not be without power. She would be without power if I used a portable unit or a PTO powered unit.

Sometimes the cheapest route is not the best route.

 

[theoldwizard1]

They way I read it, the OP wants to use the generator as his PRIMARY power source for a few years and eventually make it a standby. That means anytime someone is in the building the generator will be running. That could be easily over 2,000 hours in a year, maybe over 3000. You don't want it to run 24/7 !

Most "standby" generators will have a short life (5 years ?) with that kind of hours.

The next big problem is, this type of generator has all sorts of fancy electronics to make it start when there is no power. I don't know if their electronics can be bypassed for continuous run.

You can find 10-15kw factory refurb units on eBay all of the time.

 

[nehog]

Instead of the biggest you can get, look for the smallest that you can get by with. Really, going overboard on a generator can get expensive. Are you really doing to do a lot of work out there when the power fails? Likely as not you'll be out doing other things and not needing the power.

That said: you can also look at surplus military generator sets. I've a 15 KW set that is capable of running several houses.

 

[WhiffySpark]

They way I read it, the OP wants to use the generator as his PRIMARY power source for a few years and eventually make it a standby. That means anytime someone is in the building the generator will be running. That could be easily over 2,000 hours in a year, maybe over 3000. You don't want it to run 24/7 !

Most "standby" generators will have a short life (5 years ?) with that kind of hours.

The next big problem is, this type of generator has all sorts of fancy electronics to make it start when there is no power. I don't know if their electronics can be bypassed for continuous run.

You can find 10-15kw factory refurb units on eBay all of the time.

I'd say about 400 hours a year at the most. I'm not going to run it 24/7

 

[metaleltr]

I would look into the design life for these generators. If you never have an outage these things may run 10 hours in year-they periodically start automatically to ensure everything is operating properly, if the power goes out for 4 days we are at 58 hours in a year. So 400 hours a year is significantly more than typical. I would also look into the maintenance schedule for both the engine and the generator head

 

[matt01073]

Have you considered fuel cost if you plan on using this as a full time power source , we ran a generator welder combo to power our home for 10 days during a storm here 2 years ago and the fuel bill was terrible . that was gasoline which i know you dont want however i bet other fuels arent any better cost per hour wise .

 

[WhiffySpark]

Have you considered fuel cost if you plan on using this as a full time power source , we ran a generator welder combo to power our home for 10 days during a storm here 2 years ago and the fuel bill was terrible . that was gasoline which i know you dont want however i bet other fuels arent any better cost per hour wise .

Not a concern right now. It won't be used enough to worry about it.

I've done some digging and have found out they do make off grid generators

I've found this one but it's only a 6k

 

[willymakeit]

Check with your local city dept. Some replace backup generators for lift stations ect. These are usually nat. gas and have ecixsers ect.

 

[WhiffySpark]

Instead of the biggest you can get, look for the smallest that you can get by with. Really, going overboard on a generator can get expensive. Are you really doing to do a lot of work out there when the power fails? Likely as not you'll be out doing other things and not needing the power.

That said: you can also look at surplus military generator sets. I've a 15 KW set that is capable of running several houses.

Dont they generally have to be rewired?

 

[sublimate]

Not a concern right now. It won't be used enough to worry about it.

You sure? For a 10-12k generator running 400 hours a year you're looking at $4,000 - $5,000 per year in fuel.

So with initial purchase, maintenance, and fuel you're in for $20k for 3 years of noisy, not so reliable power with a lot of hassle.

Would be better to bite the bullet and run power sooner rather than waiting.

 

[theoldwizard1]

I've done some digging and have found out they do make off grid generators

I've found this one but it's only a 6k

Unfortunately, that one says LP fuel only !

Generators that run on Natural Gas are usually down rated.


Most Military Surplus generators run on diesel.

 

[theoldwizard1]

I'd say about 400 hours a year at the most. I'm not going to run it 24/7

Good ! Use a top quality synthetic oil, check the level daily, and change every 50-100 hours and you should be good. Engines with cast iron liners are better, but I don't know if any are still made. Water cooled is better, but typically you won't get into water cooled engines until over 20-30KW.

You never said what size compressor. If you want to stick with about a 10KW generator, I wouldn't go bigger than 2-3hp. If you have a 5hp compressor, you had better be looking at a 15KW or larger generator.

 

[Junkman]

For extended use, you want a 1800 RPM unit. Most natural gas and propane run at 3600 RPM, and they will start to self destruct if you are going to be putting 400 hours on them a year. Look at something like a Lister Petter 1800 RPM diesel gen-set. It will out live you if you take care of it.

 

[theoldwizard1]

Instead of the biggest you can get, look for the smallest that you can get by with. Really, going overboard on a generator can get expensive.

VERY TRUE ! Sales people are very good at selling you a lot more than you need.

I saw a video on YouTube about a person who installed a small mini-split so that one room would be cool when the power went out. Instead of hard wiring the compressor, he had a 120V pigtail installed and a weatherproof outlet next to the generator. He actually showed it running off of a Honda EU2000 with enough capacity for a couple of lights, a TV with cable box and a computer (no refrigerator).

 

[Mustang51js]

If your going to spend that kind of money I would look into solar for lighting and some outlets, then a smaller gen to run compressor when you need it. At least the solar you can still use in the future and pay for itself over time.

 

[Charles (in GA)]

We are going to build a shop for my business

What kind of business are you going to run that requires you only be there 400 hours a year?

Charles

 

[nehog]

Dont they generally have to be rewired?

Smaller ones are single phase, and usable directly. Bigger ones are either switchable single/3 phase, or just 3 phase. They all put out 50/60 hz (except for some special ones that are 400 hz) 120, 120/240 or 120/208 volts. I left my generator set as 3 phase and balanced my house load to three phase using two transfer switch panels.

I didn't mention in my other post that the size of the generator determines the minimum (no load) fuel consumption. A 15 KW generator would typically drink about a gallon of fuel an hour no load, and adding load then increases that consumption. My generator uses about a gallon and a half to a couple of gallons an hour. That is significant at almost $4 a gallon!

 

[WhiffySpark]

What kind of business are you going to run that requires you only be there 400 hours a year?

Charles

I do landscaping. Just a property to store equipment and bulk materials.

Just want electric in shop for lights and lift when needed

 

[48RON54]

If you are just going to be out there sometimes, plan on only running it every so often and this is only a temporary solution to get you further down the road...........

Call around to local generator service/rental companies. See what they have that might have been taken out when they installed a new permanent unit for someone. (Think municipalities etc.) usually those units will be old in age but very low hour. They might also have an old rental unit you could purchase, but those are usually way overbuilt for what you are doing and the price will reflect so IMO UNLESS hours are way high. i would also buy diesel powered if at all possible. I understand it might not be financially feasible to do so.

I work at a company that specializes in the rental/service/sales of generators and above is what I would do if I wanted a back up generator.

 

[theoldwizard1]

I do landscaping. Just a property to store equipment and bulk materials.

Just want electric in shop for lights and lift when needed

Is the compressor for the lift or for pneumatic tools ? You still have nor specified what size compressor it will be.

A small solar setup would be good to run lights.

 

[WhiffySpark]

Lifts are electric over hydr. I have a simple 33 gallon 1.8hp compressor for now.

I'm just trying to figure out if it's feasible

 

[WhiffySpark]

If you are just going to be out there sometimes, plan on only running it every so often and this is only a temporary solution to get you further down the road...........

Call around to local generator service/rental companies. See what they have that might have been taken out when they installed a new permanent unit for someone. (Think municipalities etc.) usually those units will be old in age but very low hour. They might also have an old rental unit you could purchase, but those are usually way overbuilt for what you are doing and the price will reflect so IMO UNLESS hours are way high. i would also buy diesel powered if at all possible. I understand it might not be financially feasible to do so.

I work at a company that specializes in the rental/service/sales of generators and above is what I would do if I wanted a back up generator.

Yup thank you. We actually have a company within 15 minutes of me that supplies most of the mid Atlantic. They are Kelly generator I'll look into it

 

[WhiffySpark]

Smaller ones are single phase, and usable directly. Bigger ones are either switchable single/3 phase, or just 3 phase. They all put out 50/60 hz (except for some special ones that are 400 hz) 120, 120/240 or 120/208 volts. I left my generator set as 3 phase and balanced my house load to three phase using two transfer switch panels.

I didn't mention in my other post that the size of the generator determines the minimum (no load) fuel consumption. A 15 KW generator would typically drink about a gallon of fuel an hour no load, and adding load then increases that consumption. My generator uses about a gallon and a half to a couple of gallons an hour. That is significant at almost $4 a gallon!

Thank you. Not worried about fuel consumption right now just want to know if this is feasible to do. At least until we figure out exactly where the house would go and then I would pull power from the pole

I figured it I got a 10kw we could move it to the house after the power is in for a backup

 

[theoldwizard1]

Lifts are electric over hydr. I have a simple 33 gallon 1.8hp compressor for now.

I'm just trying to figure out if it's feasible

It IS feasible. Compressors are notoriously hard starting. 10KW should be big enough, but you may need 12-15KW.

Remember, natural gas generators are down rated about 10%.

 

[themiller]

It IS feasible. Compressors are notoriously hard starting. 10KW should be big enough, but you may need 12-15KW.

Remember, natural gas generators are down rated about 10%.

... I have no problem running my 1.6HP DeWalt compressor on a generator (3200w cont/4000w surge), I doubt he needs 10k to start a 1.8HP motor...

I vote for portable inverter generator (EU7000 perhaps) or a pair of EU3000i's with a manual transfer switch. Easy to re-sell/re-use, and then you can get the appropriate generator for your house when it is built.

 

[sublimate]

I vote for portable inverter generator (EU7000 perhaps) or a pair of EU3000i's with a manual transfer switch. Easy to re-sell/re-use, and then you can get the appropriate generator for your house when it is built.

Any way to get 240v out of a pair of EU3000i's? Basically I guess you need to run them in series, but I don't think that allowed/recommended/possible. Would be interested if there's a clever way to do this.

Maybe make my own transformer using surplus shielded speaker wire and chewing gum?

 

[theoldwizard1]

... I have no problem running my 1.6HP DeWalt compressor on a generator (3200w cont/4000w surge), I doubt he needs 10k to start a 1.8HP motor...

You are probably correct !

I vote for portable inverter generator (EU7000 perhaps) or a pair of EU3000i's with a manual transfer switch. Easy to re-sell/re-use, and then you can get the appropriate generator for your house when it is built.

+! !

 

[theoldwizard1]

Any way to get 240v out of a pair of EU3000i's? Basically I guess you need to run them in series, but I don't think that allowed/recommended/possible. Would be interested if there's a clever way to do this.

Maybe make my own transformer using surplus shielded speaker wire and chewing gum?

Why make your own ! Buy a used/surplus 240/120 transformer of the appropriate size and wire it backwards. The transformer doesn't care and you will have true 240V. 2 hots, no neutral.

 

[48RON54]

I have always used 1.5 x HP = KW needed. It has worked fine for me for many years. Normally I will upsize to 2 x HP if/when possible just to play it safe, but I have yet to have a gen not be able to turn the motor using either formula.

I'm sure there is a million different formulas based on the type of motor and a lot of other possible factors that come into play.... but having rented generators day in and day out for the last 15 years, the formula above has always worked for me just fine.

 

[sublimate]

Why make your own !

Sorry, just attempted humor reference to this thread:
http://garagejournal.com/forum/showthread.php?t=248326

 

[48RON54]

^^^^ I caught the joke the first go round lol