Generators revisited

BOP

Well-Known Member
I know there was a thread one time about generators, but does anyone know how to figure out what size backup generator I'd need to keep the AC and the fridge running?
 

Blister

Active Member
Fridge, TV, some lights and a microwave you can get by with a portable unit from 2.5kw (minimum), and up to 7.5kw for window unit AC. This entails running extension cords in dark rainy/snowy conditions, from a generator running in a covered remote location to protect the genny, and to protect your family from CO2 emissions and fire hazards.

For central AC you are looking at 10kw with not inexpensive wiring, and manual or automatic changeover switches.

You want hot water make it 15kw.

Whole house, depending on whether you have any gas/oil appliances you really need to think 25kw and up at least.

That also means you need to include the installation costs, fuel cost and storage for the length of outage you are preparing for, and take the time and effort to test run your system periodically to know that it will run when needed.

If your $100 weed whacker won't start it is a pain in the A$$. If your $5000 generator does not start when the lights go out it is a MAJOR PAIN in the A$$. And worse your neighbors will chuckle at you.
 

BOP

Well-Known Member
Fridge, TV, some lights and a microwave you can get by with a portable unit from 2.5kw (minimum), and up to 7.5kw for window unit AC. This entails running extension cords in dark rainy/snowy conditions, from a generator running in a covered remote location to protect the genny, and to protect your family from CO2 emissions and fire hazards.

For central AC you are looking at 10kw with not inexpensive wiring, and manual or automatic changeover switches.

You want hot water make it 15kw.

Whole house, depending on whether you have any gas/oil appliances you really need to think 25kw and up at least.

That also means you need to include the installation costs, fuel cost and storage for the length of outage you are preparing for, and take the time and effort to test run your system periodically to know that it will run when needed.

If your $100 weed whacker won't start it is a pain in the A$$. If your $5000 generator does not start when the lights go out it is a MAJOR PAIN in the A$$. And worse your neighbors will chuckle at you.


I was afraid somebody was going to say something like that. Thanks for the info.
 

steppinthrax

Active Member
I know there was a thread one time about generators, but does anyone know how to figure out what size backup generator I'd need to keep the AC and the fridge running?

Go onto craiglist and google ONAN. Onan makes generators for the military, marine and RV. We are talking tough generators designed to work in poor conditions. You can snag one of craiglist pretty cheap. Here is a Onan

http://baltimore.craigslist.org/for/5061722821.html

That's 25KW at $3K. That will power you whole house and then some!
 

steppinthrax

Active Member
Don't forget to add a transformer to step that thing down to house voltage.

It's 3 phase, hopefully when you open the wiring box you should be able to bring out just one phase (120v). You see there is a meter for each of the 3 phases. Sadly overkill it's rated at 25K, meaning if you only only 120v you're going to get a whole ####load more than 25K. You could probably run a line down to your neighbor!!!

That's the generator I wouldn't mind getting. Just building a little doghouse around it. That generator puts those generac HD generators to shame.
 

Larry Gude

Strung Out
It's 3 phase, hopefully when you open the wiring box you should be able to bring out just one phase (120v). You see there is a meter for each of the 3 phases. Sadly overkill it's rated at 25K, meaning if you only only 120v you're going to get a whole ####load more than 25K. You could probably run a line down to your neighbor!!!

That's the generator I wouldn't mind getting. Just building a little doghouse around it. That generator puts those generac HD generators to shame.

That's not how that works. Each leg is 277v. You'd need a step down transformer. Maybe they have one to go with it?
 

Blister

Active Member
It's 3 phase, hopefully when you open the wiring box you should be able to bring out just one phase (120v). You see there is a meter for each of the 3 phases. Sadly overkill it's rated at 25K, meaning if you only only 120v you're going to get a whole ####load more than 25K. You could probably run a line down to your neighbor!!!

That's the generator I wouldn't mind getting. Just building a little doghouse around it. That generator puts those generac HD generators to shame.

Even with the transformer, your house is wired for 120/240 volt service. Even with the added transformer you would end up with 25kw at 120/208 volt 3 phase. You would only be using 16.6kw (2 phases). Your large appliances, oven, hot water heater, etc. will draw 15% higher amps to do their jobs, stressing the associated circuit breakers and wiring. Or if you use a 480 to 120/240 volt single phase transformer you end up with about 16.6kw usable load out of a 25kw generator.
 
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Chris0nllyn

Well-Known Member
I know there was a thread one time about generators, but does anyone know how to figure out what size backup generator I'd need to keep the AC and the fridge running?

You want something permanent?

You can get a lockout kit and backfeed your panelboard using a typical 5kW generator to a 30A/2P breaker.
 

b23hqb

Well-Known Member
PREMO Member
Thanks for reminding me to start up my generator and run it before the big one hits.
 

Gilligan

#*! boat!
PREMO Member
I have a 12kw Generac, propane powered. I bought that used/repaired from a guy that services Generacs.

I recently purchased a 25kw Kubota diesel powered generator with Dynagen 300 automatic controller from an outfit in Georgia for only $5600; a heck of a deal I thought. It's 220V single phase...directly compatible with standard house wiring. The manual transfer switch I bought was an additional $400.
 

itsbob

I bowl overhand
I was afraid somebody was going to say something like that. Thanks for the info.

I've got a PTO generator, goes on the back of the tractor. That it runs off of the tractor PTO there is no (or very little) maintenance. NO oil to worry about, no fuel getting old.. never have to worry about it starting.

Since I use my tractor every week, it gets regular maintenance, and is always full of fuel, most of the issues of a generator are already taken care of. I think the biggest issue with generators is they sit somewhere forgotten, until you need it, then you find the fuel has congealed in the fuel lines, the spark plugs are fouled.. oil is contaminated.. just normal issues with storing combustion engines for a period of time.

The only issue is remembering to hook it up BEFORE electric goes out. It really sucks being outside in the middle of a snow storm or thunderstorm hooking up the PTO to the tractor..

I've got a 10K and it powers everything in the house EXCEPT the microwaves..
 

Gilligan

#*! boat!
PREMO Member
I've got a PTO generator, goes on the back of the tractor. .

Those are great. We used one as backup for our dairy barn for many years. I almost bought one to go on the back of my John Deer 770 before I got the deal on the 12kw Generac instead. I'm still not sure I made the right choice there....if it runs out of propane I'm screwed. Diesel I can probably always get and haul myself.
 
I've got a PTO generator, goes on the back of the tractor. That it runs off of the tractor PTO there is no (or very little) maintenance. NO oil to worry about, no fuel getting old.. never have to worry about it starting.

Since I use my tractor every week, it gets regular maintenance, and is always full of fuel, most of the issues of a generator are already taken care of. I think the biggest issue with generators is they sit somewhere forgotten, until you need it, then you find the fuel has congealed in the fuel lines, the spark plugs are fouled.. oil is contaminated.. just normal issues with storing combustion engines for a period of time.

The only issue is remembering to hook it up BEFORE electric goes out. It really sucks being outside in the middle of a snow storm or thunderstorm hooking up the PTO to the tractor..

I've got a 10K and it powers everything in the house EXCEPT the microwaves..
Bob, isn't there also an issue with making sure the genny is bolted down? :biggrin:

I've got a 2200 and a 3500 watt genny that gets plugged into a dedicated outlet outside with an interlock on the breaker panel. The 3500 will run everything but the A/C. I can get hot water if everything else is shut off.

:generatorenvy: :ohwell:
 
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