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Discussion Starter · #1 · (Edited)
I just stumbled onto this forum - hopefully someone can educate me a little.

After a 4 day outage, I have decided to get a standby generator. I will not be doing any of the installation except for deciding what I want and contracting the work.

My house is 200 amp from utility and splits into 2 200amp primary (independent) house panels. I have two heat pump / electric strip heaters. All electric home. I will be installing a 250 gallon propane tank just for this.

Here are options and questions.
1: buy an 11kw or 14kw prewired unit for 10 or 12 circuits. This is fall back plan - but really would prefer more circuits.

2: buy an 11kw Generac unit with 200amp load (SE) shedding ATS. This is preferred option but not sure how to wire it. Can I do this?
- Move all the circuits I want to control onto one of my 200 amp panels
- hook the generator ATS from one of the utility branches directly to the one 200amp panel, leaving the other one untouched. During an outage, the one panel will stay dead while the other will be load managed?

Thanks for any help.
Mike
 

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Hi,

From the size of your service are you sure that an 11 or 14kw unit will handle your loads? Most of the costs associated with a generator install are related to the installation - not the machine. You might look at something a bit larger, maybe the 20kw range.

Do a load calc. You don't really want to have a generator running anywhere near 100% load for very long.

Do you have any other source of heat?

On the ATS, my preference would also be to have one panel where I could run basically anything I chose instead of being limited to the 10-16 circuits - just for convenience.

Some other things. It takes about 2 hp per 1kw. On a 14kw generator you'd need about 28 horsepower so your burn will be about 280,000 btu/hr. Propane has about 92,000 btus/gallon. Figure 3 gallon an hour burn - full load. Basically, just over 3 days at full load.

Will the propane tank be underground? I ask because as you draw from the tank the vaporization rate drops. If this tank is above ground and gets very cold it may not vaporize enough to provide enough fuel as the level drops.
 

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Discussion Starter · #3 ·
Hi,

From the size of your service are you sure that an 11 or 14kw unit will handle your loads? Most of the costs associated with a generator install are related to the installation - not the machine. You might look at something a bit larger, maybe the 20kw range.

Do a load calc. You don't really want to have a generator running anywhere near 100% load for very long.

Do you have any other source of heat?

On the ATS, my preference would also be to have one panel where I could run basically anything I chose instead of being limited to the 10-16 circuits - just for convenience.

Some other things. It takes about 2 hp per 1kw. On a 14kw generator you'd need about 28 horsepower so your burn will be about 280,000 btu/hr. Propane has about 92,000 btus/gallon. Figure 3 gallon an hour burn - full load. Basically, just over 3 days at full load.

Will the propane tank be underground? I ask because as you draw from the tank the vaporization rate drops. If this tank is above ground and gets very cold it may not vaporize enough to provide enough fuel as the level drops.
I think an 11K unit will work as I really want just selected circuits to work - not the whole house during an outage - I actually don't need heat at all; my fireplace is ducted through the main part of the house and will do fine as long as its fan works. The 11kw unit is a smaller engine, quieter, and much more efficient as well as less expensive. I expect to run at about 7kw.

That said, I would like to get the smaller AC to work for a summer outage. I am trying to find its starting requirements, which might force me to a larger unit or forget any AC in the summer.

I am still trying to wrap my arms around why electrical installation costs are so high. In my case, the electrician will have to move / exchange about 6 circuits from the one panel and then connect the ATS in line with the panel, generator, and hook up 4 load management modules. Maybe I am missing something.

Thanks for the feedback.
Mike
 

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With Good Automatic Load Sheading system, I have found that most homes with a 200 amp service will operate on and calculate for 12-16 KW Generators. One thing to look at when selecting the generator is the size of the output circuit breaker, I have seen supposed 20 KW units with 80 amp CB’s other manufactures with the same 20 KW use a 100 AMP. It’s a confusing world of number games when dealing with these little home power systems. Of note the Load shedding systems offered by GE, Milbank, B&S and Rheem, are extremely well thought out and actually measure the load on the generator and brings on the locked out devices in an orderly fashion. This can go a long way in keeping cost down, selecting a unit that meets your needs without oversizing..
 

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My cousin is a local owner/contractor who installs and repairs Generac standby generators for two big box stores. If you are looking to get a standby generator I would highly recommend going with another brand. Generac is not the company it use to be an neither are their generators. He works on these all day and I can't tell you how many issues he has with getting parts and support from Generac. Every time he submits a warranty claim Generac will typically go out of their way to find a way to deny the claim. He often spends hours on the phone fighting with them just to get paid for a customers warranty claim. Obtaining parts is no better, he sometimes has to wait weeks for parts because Generac does not have them in stock. Just wanted to add my .02 cents and help you avoid headaches in the future.
 

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My cousin is a local owner/contractor who installs and repairs Generac standby generators for two big box stores. If you are looking to get a standby generator I would highly recommend going with another brand. Generac is not the company it use to be an neither are their generators. He works on these all day and I can't tell you how many issues he has with getting parts and support from Generac. Every time he submits a warranty claim Generac will typically go out of their way to find a way to deny the claim. He often spends hours on the phone fighting with them just to get paid for a customers warranty claim. Obtaining parts is no better, he sometimes has to wait weeks for parts because Generac does not have them in stock. Just wanted to add my .02 cents and help you avoid headaches in the future.
I've heard similar rumblings from my neighbors who have whole house Generac units. I loaned one neighbor my little 3250 and a couple of extension cords for a outage. He had been waiting for a "board" for five weeks. Any other input on Generac?
 

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I have several neighbors who own standby Generacs and they have generally been happy with them, but these folks actually MAINTAIN them regularly. I have other acquaintances who have not taken such good care of them and have had breakdowns, and then had long waits for parts. I think it's really important to have a trustworthy servicing dealer to have a good, lasting experience with them.

I personally own a small Generac Series 3500XL Model 09441-5 which is now over 20 years old, purchased for the ice storm of 1998. It worked fine until the wind storm of 2017 and when I fired it up, it broke the intake valve keeper, and when I replaced that with one borrowed from my Honda snowblower, it then broke the valve stem itself. I had to scrounge aftermarket parts, since they were not available from Generac. I purchased a larger PowerMate, since it was the only genset available that day, and it has been working happily for 50+ hours now through a couple of major outages. The Generac is on the bench, just in case, but I probably would not purchase another one. I have an Onan at our island cottage that runs 100+ hours a summer, and would probably look that way in the future based on my experience.
 
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