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Discussion Starter #1
Hello All,

The other week we lost power for about an entire day, by all means not as bad as others experience but of course we end up trying to keep the house warm in the winter, keeping the freezer cold, and everything else we take for granted.

I think we'd want something pretty substantial in case of an extended outage, a large wattage natural gas powered unit. We have a 200amp panel with all but 2 spaces occupied, a 100amp panel in the pool shed that also powers a hot tub, and a 100amp panel in our detached shop. We have 2 fridges and a large freezer running 24/7. Gas appliances though.

I'd like something capable of running most or all of the house, does that mean something like 20kw? Does anyone have experience with specific brands that they'd recommend? Generac, Kohler, and Briggs&Stratton are the ones we saw at the last home show.

Thanks for any input!!
 

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I have a 15kw Generac that I installed at least 12 yrs ago. I too have a 200a panel in the house and a 100a subpanel to the garage. It's been a pretty good unit. There are some things I did do different and some things I would look for again in a new unit. Most at the time came pre-wired with the feed and controls in a 50' flexible conduit. #1, I didn't like the limited length or the controls and power in the same raceway, so I bought some 3/4" and 1 1/2" PVC conduit and wiring for each circuit and placed the generator where I wanted, behind the garage, then fed the house underground. One thing I should have done was rotate the placement 180° so the exhaust noise was pointing away from the house. It's not bad, but that's a big thing to consider if it is running for hours on end, especially at night.

The new ones may be different, but I don't like that mine does not idle when not under load. When it starts it's full speed and when it shuts down it does the same. It's got to be hard on the engine.

The other thing I don't like is the ATS (Automatic Transfer Switch) is wired with branch circuit breakers, I think 10 total, and has wiring that extends into the house panel. You then remove the wiring from each circuit you want to feed with the generator and wirenut them together. I would much prefer having the whole panel fed through the ATS from both sources; the utility and the generator. Maybe the new ones are different. I have always wanted to re-do mine but still haven't done so.

Mine is propane. I think NG is a little less in BTU, so less power from what I've read. Not much, but some. If money were no object, I would look into an Onan diesel.

A lot will depend whether you do the install yourself or have it done. I've found that Generac is very territorial about parts information and in my area there are a few registered dealers which vary greatly in their service, so be aware that who you choose makes a big difference. I won't go into details, but I had an issue, called 2 dealers for their help and was told by one I needed a new engine at $4500. The other dealer was more helpful, installed a new regulator and showed me some things to look for.

One of the biggest things overlooked is the frequency. They need to be tested under load, as much load as possible.
 

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Discussion Starter #3
Great input, thank you!

I agree, I'd much prefer to have a unit that powered my entire main panel directly in the event of power loss. I'd have it hooked up by an electrician to make sure it was correct.

I think the NG vs diesel would depend on whether there is an NG unit that could handle the load...I'm not sure how to estimate what I'd need.
 

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Just the other day I was ready to have my BIL pull the trigger on a portable 17.5 kw generator for his house.

I discovered a lot (maybe all) only provide a maximum output of 50 amps from a single receptacle. On the particular generator I was looking to recommend it had 1-240v 50 amp, 2- 240v 30 amp and and a few 120v 15 amp and 20 amp receptacles.

I am not an expert in the field of generators or their hookup but I have no idea how you would hook one of these up to a house panel and provide the rated 240v 73 amps.
I for one felt mislead.
 

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I think the NG vs diesel would depend on whether there is an NG unit that could handle the load...I'm not sure how to estimate what I'd need.
You won't have any issues finding a NG unit that will handle the load. With diesel you'll have to install a storage tank and deal with delivery / storage / treatment issues. With NG you should have unlimited fuel unless the service is interrupted by some kind of disaster.
 

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Just the other day I was ready to have my BIL pull the trigger on a portable 17.5 kw generator for his house.

I discovered a lot (maybe all) only provide a maximum output of 50 amps from a single receptacle. On the particular generator I was looking to recommend it had 1-240v 50 amp, 2- 240v 30 amp and and a few 120v 15 amp and 20 amp receptacles.

I am not an expert in the field of generators or their hookup but I have no idea how you would hook one of these up to a house panel and provide the rated 240v 73 amps.
I for one felt mislead.
Wow... that is a huge "portable" generator. 50-amps seems to be about it for residential portable units. The normal way to hook up is via a transfer switch, an interlock in the breaker panel or one of the GenerLink gizmos that attach to the meter base. Then you simply install a 50-amp male receptacle outside somewhere convenient into which you will plug-in the generator. It's very similar to the questionable "backfeed" method that is so popular except when done correctly it is completely legal and it does not pose an electrocution risk to anyone.
 

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You won't have any issues finding a NG unit that will handle the load. With diesel you'll have to install a storage tank and deal with delivery / storage / treatment issues. With NG you should have unlimited fuel unless the service is interrupted by some kind of disaster.
Oh, good point. That was the other thing I ran into with the propane. I ended up buying the tank, regulators, and paid for the installation because that was the only thing in our house using propane. I have since found out that other fuel dealers would have let me lease/rent and simply pay for the fuel. I ended up paying $750 at the time. The other issue with that is the tanks have dates on them and will get tot the point where no one will fill them. Just something to keep in mind too.
 

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Wow... that is a huge "portable" generator. 50-amps seems to be about it for residential portable units. The normal way to hook up is via a transfer switch, an interlock in the breaker panel or one of the GenerLink gizmos that attach to the meter base. Then you simply install a 50-amp male receptacle outside somewhere convenient into which you will plug-in the generator. It's very similar to the questionable "backfeed" method that is so popular except when done correctly it is completely legal and it does not pose an electrocution risk to anyone.
I know all that but I was expecting a single 73 amp output even if it were a hardwired output. NOPE!
 

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I know all that but I was expecting a single 73 amp output even if it were a hardwired output. NOPE!
I'm sure there's probably some "code" issue somewhere. Plus, hardwired connections wouldn't make much sense on a portable unit.

Maybe your BIL would be better off with a slightly smaller generator since it appears he may not be able to use all of the capacity anyway and the larger engine will just burn more fuel.

Probably where you could use more of the capacity would be if using extension cords as you could attach things to the multiple outlets on the generator and not be limited by the single 50-amp connection.
 

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I'm sure there's probably some "code" issue somewhere. Plus, hardwired connections wouldn't make much sense on a portable unit.

Maybe your BIL would be better off with a slightly smaller generator since it appears he may not be able to use all of the capacity anyway and the larger engine will just burn more fuel.

Probably where you could use more of the capacity would be if using extension cords as you could attach things to the multiple outlets on the generator and not be limited by the single 50-amp connection.
Yeah, I'm sure, just never really thought about it and was sort of blindsided by it all.
I guess he will be going with a 15 kw.
 

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Discussion Starter #11
We would probably go with a permanent NG unit, wired into the meter with the transfer switch.

How many KW would we want to shop for to make sure we'd have plenty?

Also, does anyone have any strong convictions about certain brands?
 

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I would analyze your electric bill over the last few years, with winter and summer to see what kind of usage you have had. Your utility company could help you with that, just explain what you are planning to do. An electrician could help you with that too. Something like this online calculator can give guidance too. https://www.electricgeneratorsdirect.com/stories/1469-Easily-Size-Your-Home-Standby-Generator.html?gclid=EAIaIQobChMI2ZfV46nx2QIVTjyBCh3rpQKvEAAYAiAAEgJjbvD_BwE
Then think about what you might add in the future, etc. That being said, unless you have an unusually large load, a 17-20kw should be fine.

One thing I found when deciding was that Generac used the same HP engine for a few different sized generators. So I decided it made more sense to get the next size up which used a larger engine, thinking it would not work so hard as the smaller one.

Permanent NG means that it is 'piped' to your house, right? so you don't have to worry about fuel storage, tanks, etc. That's a plus.
 

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We would probably go with a permanent NG unit, wired into the meter with the transfer switch.

How many KW would we want to shop for to make sure we'd have plenty?

Also, does anyone have any strong convictions about certain brands?
A huge deciding factor concerning a whole house, or portable generator for that matter, is how do you heat you house. If you have a heat pump and electric coil back up, you will need more kW than if you heat with a furnace.

Most whole house generators are wired with an automatic transfer switch that automatically disconnects your panel from the utility and connects your panel to the generator.

My dad has a heat pump and electric coil back up and electric range. His whole house generator is a 30 kW and it work flawlessly. If you do not have electric heat and you had said you have gas appliances, then 20 kW would do the job.
 

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We would probably go with a permanent NG unit, wired into the meter with the transfer switch.

How many KW would we want to shop for to make sure we'd have plenty?

Also, does anyone have any strong convictions about certain brands?
I install 50-150 15kw-30kw diesel standby generators a year in the telcom industry. Mainly Generac diesel with around a 200 gal tank under it. I personally would go with natural gas if available. Unit is much smaller because it's not setting on a tank. I also would do a full automatic transfer switch instead of a load shed setup.

Look in the 12k range. Around 50amps at 240v and a 100amps at 120v. Shouldn't take much more than that. I don't know your peak power demand so if I were you I'd come up with what would be peak demand and go from there. Generac seems to be a good brand. If you stick with the major brands, you shouldn't have a problem. Just don't go cheap. In this case cheap is not what you want to rely on.
 

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Oh, good point. That was the other thing I ran into with the propane. I ended up buying the tank, regulators, and paid for the installation because that was the only thing in our house using propane. I have since found out that other fuel dealers would have let me lease/rent and simply pay for the fuel. I ended up paying $750 at the time. The other issue with that is the tanks have dates on them and will get tot the point where no one will fill them. Just something to keep in mind too.
Not sure how big of tank you purchased, but once they hit their date, they can be recertified and continued to use.
 

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I have similar electrical demands to what you describe. 200A main panell, 2 free spots, 100A subpanel for the barn. I also have a well, and ruunning the well pump is critical. Also 2 electric water heaters, natural gas heat plus central AC, 2 thru wall heat pumps for barn workshop and tack rooms,

I had been using a Honda 7000is wired to a 30A breaker in the main panel with an interlock switch. I also installed 2 watt usage meters next to the main panel to monitor the A and B sides of the panel, so I could attempt to keep the load balanced. The genertator worked for my needs, but just barely. For example, pretty much everthing in the house had to be off to start up the well pump.

So I finally bit the bullet and had a Generac 22KW natural gas unit installed. FYI I paid just a bit over $8000 for the Generac generator, Generac automatic power transfer switch, and the labor for running the wiring and the gas plumbing. I did not go with the Generac sales system; I hired a local elecrician to obtain the generator and do the installation. I'd paid $4000 for the Honda generator, so the Generac price looked like a real bargain from my perspective. The Honda now lists for $4500. I must say the Honda was totally reliable; it started with the first button push every time, and was quieter than my Generac.

The Generac runs everything I hoped. The well, water heater, and heat, plus refrigerator, occasional microwave oven use, the usual lights and electronics. No more going outside in the cold to start, stop, and re-fuel a portable genertor. As long as the natural gas system keeps flowing, we're warm, clean, fed, and can flush the toilets. After the first few minutes, you pretty much tune out the noise of the running generator.
 

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We had a 22k Generac whole house autoswitch system installed the summer of 2016 through Costco (the unit is branded Honeywell) by a Generac dealer. We had it placed about 70' from the meter/svc entrance and had to run propane about 40' from an existing point. Counting everything, including tax, permits and propane supply line work, it was about $9600. After figuring cash back via costco membership and CC rebates, plus 10% costco cash card, net was actually more like $8400.

I posted a pictorial of the install here in the ham radio portion of another board:

https://www.ar15.com/forums/outdoors/Standby_Generator___ETA__installed__up_andamp__running_/22-686565/

ended up adding a second 500 gallon LP tank & documented it here:

http://www.greentractortalk.com/forums/home-workshop-projects/134282-got-new-500-gallon-lp-tank.html

Nick
 

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I have a 15kw Generac that I installed at least 12 yrs ago. I too have a 200a panel in the house and a 100a subpanel to the garage. It's been a pretty good unit. There are some things I did do different and some things I would look for again in a new unit. Most at the time came pre-wired with the feed and controls in a 50' flexible conduit. #1, I didn't like the limited length or the controls and power in the same raceway, so I bought some 3/4" and 1 1/2" PVC conduit and wiring for each circuit and placed the generator where I wanted, behind the garage, then fed the house underground. One thing I should have done was rotate the placement 180° so the exhaust noise was pointing away from the house. It's not bad, but that's a big thing to consider if it is running for hours on end, especially at night.

The new ones may be different, but I don't like that mine does not idle when not under load. When it starts it's full speed and when it shuts down it does the same. It's got to be hard on the engine.

The other thing I don't like is the ATS (Automatic Transfer Switch) is wired with branch circuit breakers, I think 10 total, and has wiring that extends into the house panel. You then remove the wiring from each circuit you want to feed with the generator and wirenut them together. I would much prefer having the whole panel fed through the ATS from both sources; the utility and the generator. Maybe the new ones are different. I have always wanted to re-do mine but still haven't done so.

Mine is propane. I think NG is a little less in BTU, so less power from what I've read. Not much, but some. If money were no object, I would look into an Onan diesel.

A lot will depend whether you do the install yourself or have it done. I've found that Generac is very territorial about parts information and in my area there are a few registered dealers which vary greatly in their service, so be aware that who you choose makes a big difference. I won't go into details, but I had an issue, called 2 dealers for their help and was told by one I needed a new engine at $4500. The other dealer was more helpful, installed a new regulator and showed me some things to look for.

One of the biggest things overlooked is the frequency. They need to be tested under load, as much load as possible.
Sounds like we have the same unit, we have 400+ hours on it and has been rock-solid. They do not use the separate 10 space panel anymore, now they include 200 transfer switches. I changes most od the breakers to tandems for added circuits, and added the hour meter. The only real issue with mine is the steel case is rusting away-but the new ones have aluminum ones. If it broke, I'd replace it with a 20kw unit.

OP: There are MANY threads on this if you search some, lots of great info on these systems.
 

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Discussion Starter #19
More great info!

We have forced air heat, AC, gas water heater, gas stove, gas dryers. Biggest demands are the 2 fridges and 1 freezer, 240 volt outdoor hot tub, AC.
 

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We have forced air heat, AC, gas water heater, gas stove, gas dryers. Biggest demands are the 2 fridges and 1 freezer, 240 volt outdoor hot tub, AC.
I'm guessing the hot tub is not a critical appliance during a power failure. :) Same with the AC as I see you are in NY. I'm in PA and having heat during an outage in the winter was priority over AC during the summer. I mean, if it gets really hot everyone will just have to get nekid. :laugh:
 
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