Built in Generators w/transfer switch

[Jsf721]

I am looking into installing a NG Generator to power my house in the event of a power outage. We are just about back to normal after a devastating amount of damage due to hurricane sandy.

We were without power for 12+ days and while I did have a generator running (gasoline) getting gas was the problem. WTF NY does not require gas stations to have generators is beyond me.

I would like to draw on the experience anyone might have as well as get some answers to some specific questions.

1. Generac is one brand I am familiar with. I had a portable 15,000KW unit I rented for the last storm. Other than changing the oil and filling it will gas it was flawless. Getting gasoline was the issue. Any other top quality brands for "installed" generators??

1a. Thoughts on a manual vs automatic transfer switch? My concern is I was flooded in the last storm. If someone were home and the automatic transfer switch kicked over to the generator, whould the people standing in the 3 ft of water get zapped with electricity ? is there a safety for that? This was the first time we saw any water in the house in the 18 years I own the house and I grew up 1/4 mile closer to the ocean and never saw water in the house in the 45 years I have been alive.

2. Does the generator burn more fuel (NG) under higher load? Meaning if I run a few lights or the whole house and A/C will it burn less or more fuel?

3. How do I determine the size I need to run the house under the load?

4. Any tips from people who have gone through this before?

5. What am I not asking that I should know?


Thanks,

Jeff

 

[Jsf721]

I am looking into installing a NG Generator to power my house in the even of a power outage. We are just about back to normal after a devastating amount of damage due to huirricane sandy.

We were without power for 12+ days and while I did have a generator running (gasoline) getting gas was the problem. WTF NY does not require gas stations to have generators is beyond me.

I would like to draw on the experience anyone might have as well as get some answers to some specific questions.

1. Generac is one brand I am familiar with. I had a portable 15,000KW unit I rented for the last storm. Other than changing the oil and filling it will gas it was flawless. Getting gasoline was the issue. Anyother top quality brands for "installed" generators??

1a. Thoughts on a manual vs automatic transfer switch? My concern is I was flooded in the last storm. If someone were home and the automatic transfer switch kicked over to the generator, whould the people standing in the 3 ft of water get zapped with electricity ? Is there a safety to prevent that? This was the first time we saw any water in the house in the 18 years I own the house and I grew up 1/4 mile closer to the ocean and never saw water in the house in the 45 years I have been alive but you can never say never again.

2. Does the generator burn more fuel (NG) under higher load? Meaning if I run a few lights or the whole house and A/C will it burn less or more fuel?

3. How do I determine the size I need to run the house under the load?

4. Any tips from people who have gone through this before?

5. What am I not asking that I should know?


Thanks,

Jeff

 

[bdamico]

this has been covered a lot in the lighting/electrical section

 

[mjeff87]

I have a Generac 20K with an auto transfer switch on my house. I can't comment on the standing water question, I'm sure there's some kind of safety to deal with that. I will say that with an auto transfer switch, the thing will run if we're not home, and if my wife is home by herself she doesn't have to do a thing to have power. I like that. On the sizing, you'll have to consider what you want to run, essential circuits or whole-house. There's a definate step up in pricing when you get over 8-10K, and if you're looking to run a heat pump or A/C you'll need to make that jump. I had the local contractor come out and do a site eval and work up a load calculation for us (we wanted whole-house backup) and they came up with 17.5K. I asked what the price difference was between the 17.5K and the next step up (20K) and it was less than $1000 so I upped it to 20K and never looked back.

I also had to get my gas meter upgraded to a commercial one to be able to supply the genset (I have gas heat/stove/water heater as well). Gas company did that for free, but you have to factor that into the work schedule as well. From contract sign to install took us about 2.5 months, with ordering and delivering the generator, meter upgrade, inspections, etc.)....I'd imagine they are pretty backed up now on orders so your lead time may be longer, just an FYI. I heard a news blip yesterday that Generac stock is going thru the roof thanks to Sandy....

anything else I can help you with, just let me know.

Jeff

edit: here's my "build" thread on the generator, might help you some

http://garagejournal.com/forum/showthread.php?t=137410

 

[Jsf721]

Thanks very much, I will read it tonight (at work now) and i appreciate the link. I was looking at that exact model. The 15,000 KW powered everything I asked it to during the storm. Heat, HW and lights. plus I had extension cords running to 4 neighbors houses to power a light an charge cell phones.

I have a Generac 20K with an auto transfer switch on my house. I can't comment on the standing water question, I'm sure there's some kind of safety to deal with that. I will say that with an auto transfer switch, the thing will run if we're not home, and if my wife is home by herself she doesn't have to do a thing to have power. I like that. On the sizing, you'll have to consider what you want to run, essential circuits or whole-house. There's a definate step up in pricing when you get over 8-10K, and if you're looking to run a heat pump or A/C you'll need to make that jump. I had the local contractor come out and do a site eval and work up a load calculation for us (we wanted whole-house backup) and they came up with 17.5K. I asked what the price difference was between the 17.5K and the next step up (20K) and it was less than $1000 so I upped it to 20K and never looked back.

I also had to get my gas meter upgraded to a commercial one to be able to supply the genset (I have gas heat/stove/water heater as well). Gas company did that for free, but you have to factor that into the work schedule as well. From contract sign to install took us about 2.5 months, with ordering and delivering the generator, meter upgrade, inspections, etc.)....I'd imagine they are pretty backed up now on orders so your lead time may be longer, just an FYI. I heard a news blip yesterday that Generac stock is going thru the roof thanks to Sandy....

anything else I can help you with, just let me know.

Jeff

edit: here's my "build" thread on the generator, might help you some

http://garagejournal.com/forum/showthread.php?t=137410

 

[FJ 432]

I am looking into installing a NG Generator to power my house in the event of a power outage. We are just about back to normal after a devastating amount of damage due to hurricane sandy.

We were without power for 12+ days and while I did have a generator running (gasoline) getting gas was the problem. WTF NY does not require gas stations to have generators is beyond me.

I would like to draw on the experience anyone might have as well as get some answers to some specific questions.

1. Generac is one brand I am familiar with. I had a portable 15,000KW unit I rented for the last storm. Other than changing the oil and filling it will gas it was flawless. Getting gasoline was the issue. Any other top quality brands for "installed" generators??I work for a company that installs generators for data centers (cummins). That being said Generac units are owned by our top executives for their personal homes. A good choice.

1a. Thoughts on a manual vs automatic transfer switch? My concern is I was flooded in the last storm. If someone were home and the automatic transfer switch kicked over to the generator, whould the people standing in the 3 ft of water get zapped with electricity ? is there a safety for that? This was the first time we saw any water in the house in the 18 years I own the house and I grew up 1/4 mile closer to the ocean and never saw water in the house in the 45 years I have been alive. Go with an ATS if you can afford it. Yes there is safety to prevent shock.

2. Does the generator burn more fuel (NG) under higher load? Meaning if I run a few lights or the whole house and A/C will it burn less or more fuel? Yes. And natural gas generators are not as efficient as diesel or gas generators so you have to up size according to you needs.

3. How do I determine the size I need to run the house under the load?Pull out your last power bill and then determine what is necessary and what is luxury. Talk with an electrician who installs these for a living.

4. Any tips from people who have gone through this before?

5. What am I not asking that I should know?


Thanks,

Jeff

See my comments above.

 

[Jsf721]

Thanks, I just made an appointment for an Electrical Contractor Listed as a sales and service center with a 5 star rating to come to my home and perform a complete survey. They have their own plumber, labor for trenching and obviously electricians. They also handle the permit service. 4 week lead time after deposit for completion. He has 17 and 20KW units in stock and I guestimate that is what I will need approximately. Wonder if I am right.

Guy cannot meet until Feb 25th. He is and has been booked solid 6 days a week since the storm.



Join Date: Aug 2010
Location: Littleton Colorado
Posts: 553 Re: Built in Generators w/transfer switch

--------------------------------------------------------------------------------

Quote:
Originally Posted by Jsf721
I am looking into installing a NG Generator to power my house in the event of a power outage. We are just about back to normal after a devastating amount of damage due to hurricane sandy.

We were without power for 12+ days and while I did have a generator running (gasoline) getting gas was the problem. WTF NY does not require gas stations to have generators is beyond me.

I would like to draw on the experience anyone might have as well as get some answers to some specific questions.

1. Generac is one brand I am familiar with. I had a portable 15,000KW unit I rented for the last storm. Other than changing the oil and filling it will gas it was flawless. Getting gasoline was the issue. Any other top quality brands for "installed" generators??I work for a company that installs generators for data centers (cummins). That being said Generac units are owned by our top executives for their personal homes. A good choice.

1a. Thoughts on a manual vs automatic transfer switch? My concern is I was flooded in the last storm. If someone were home and the automatic transfer switch kicked over to the generator, whould the people standing in the 3 ft of water get zapped with electricity ? is there a safety for that? This was the first time we saw any water in the house in the 18 years I own the house and I grew up 1/4 mile closer to the ocean and never saw water in the house in the 45 years I have been alive. Go with an ATS if you can afford it. Yes there is safety to prevent shock.

2. Does the generator burn more fuel (NG) under higher load? Meaning if I run a few lights or the whole house and A/C will it burn less or more fuel? Yes. And natural gas generators are not as efficient as diesel or gas generators so you have to up size according to you needs.

3. How do I determine the size I need to run the house under the load?Pull out your last power bill and then determine what is necessary and what is luxury. Talk with an electrician who installs these for a living.

4. Any tips from people who have gone through this before?

5. What am I not asking that I should know?


Thanks,

Jeff

See my comments above.

 

[Tim Kennedy]

hardydiesel.com --- big selection, knowledgeable people

 

[Jsf721]

Thanks WIll check it out.

hardydiesel.com --- big selection, knowledgeable people

 

[aandpdan]

One additional thing to consider, if the area floods, your natural gas supplier may turn off the service.

 

[kbs2244]

A second vote on the availability of NG in a disaster scenario.
The fire guys often turn off the gas.
In spite of its hassles, you may want to check into some kind of on site fuel storage.

 

[mikester]

I thought about a backup generator like that but my street doesnt have gas lines and I dont want to have a huge propane tank in my yard. Im planning to go with a diesel set up in the spring. Plus they run at half the RPMs.

 

[aandpdan]

I thought about a backup generator like that but my street doesnt have gas lines and I dont want to have a huge propane tank in my yard. Im planning to go with a diesel set up in the spring. Plus they run at half the RPMs.

1800 RPM propane (gas) powered generators do exist. You can always bury the propane tank in the ground.

 

[bjmac]

I have a Genarac 10K that runs on Propane. Auto transfer switch. Works great. We have several outages per year (mostly tree fall due to storms and snow) I have Propane heat, all other normal household systems. Power fails, 10 seconds later house has power again until power is restored. If we are gone, the Gen Set maintains all systems. If we are home, we just refrain from using Elect Range and Dryer. It's been a real valuable addition. I was able to install it myself after Propane guy did his thing.

 

[Greg_R]

1. Generac is one brand I am familiar with. I had a portable 15,000KW unit I rented for the last storm. Other than changing the oil and filling it will gas it was flawless. Getting gasoline was the issue. Any other top quality brands for "installed" generators??

CAT, Kohler, Cummings Onan, Powermate, Winco, Honda, & various cars like the Prius... there are a lot of brands out there. I would look at the engine, run time, and construction quality.

Thoughts on a manual vs automatic transfer switch?

IMO, manual works just fine and is significantly cheaper. Have the electrician put a single lightbulb on the metered supply so you know when power comes back on. Water / electricity problems should be avoided by good generator placement and not turning it on when there is standing water.

Does the generator burn more fuel (NG) under higher load?

More electrical load consumes more fuel.

How do I determine the size I need to run the house under the load?

Add up the devices you want to simultaneously run.

Any tips from people who have gone through this before?

Consider used high quality generators (auctions, etc.). However, these are probably all snatched up after Sandy.

What am I not asking that I should know?

You need a generator, transfer switch, and panel. You should determine the frequency, cost, and difficulty of the maintenance for your prospective generator. Also, if you're going with gas then consider supplementary storage tanks in case the gas lines to your neighborhood are broken.

 

[theoldwizard1]

Besides Generac, Briggs & Stratton and Kohler sell "whole home" generators.

Go for the ATS if you can afford it. Size has a lot to do with what you must have running, (well, sump pump, furnace, heat pump) and what you can live without (electric stove, electric dryer, electric water heater, A/C). One or 2 small window A/C will get you through a couple of weeks and don't cost that much.

Once you have analyzed at your load requirements, you will likely find that you can get by on less than 10kw. I don't understand why, but usually systems with ATS are much larger. Probably because they feel people are too STUPID to turn off their stove, dryer, water heater and A/C !

If I did not have NG available, I would go with Propane (LP). You can buy a tank and bury it. Anyone looking a diesel should find out what it is going to cost to have 10+ gallons delivered, especially in an area that has no electricity.

 

[soj]

Just a personal opinion, but I would (will) stay away from Generac. I had one (8KW portable) that worked fine for a little over a year, then it just quit. Gen output dead, engine ran fine. The local Generac service center could not repair it without replacing the entire generator head, they could not determine where the problem was (rotor and stator and capacitor all checked OK, but still no output). I let a couple of other shops look at it as well, and they all scratched their heads. Never another Generac for me. YMMV. I also tried to get help and advice over at the Smokestack forum. Most of the generator guys there seem to be professional installers and most have a dislike for Generac. I am looking at a system like the OP and will probably go with Kohler. Drive around your local hospital, look for the standby generator, it will most likely be a Kohler. Every cell tower I have ever been close enough to see the generator has been a Kohler. I know some have already replied with positive experience with Generac, and I don't discount their experiences. I was very pleased with mine while it worked, but that was only a $1500 portable. I am not willing to risk the dollars it will take for a standby system on the same company.

 

[aandpdan]

Once you have analyzed at your load requirements, you will likely find that you can get by on less than 10kw. I don't understand why, but usually systems with ATS are much larger. Probably because they feel people are too STUPID to turn off their stove, dryer, water heater and A/C !

Bingo!

It's required by the NEC, 2008 version, if I recall. With an ATS the generator is required to be sized to the connected load, UNLESS load shedding is used.

You can get around it. Put in a subpanel for just those circuits you want to run on the ATS.

 

[theoldwizard1]

Bingo!

It's required by the NEC, 2008 version, if I recall. With an ATS the generator is required to be sized to the connected load, UNLESS load shedding is used.

Yeah, for STUPID people !

You can get around it. Put in a subpanel for just those circuits you want to run on the ATS.

More expense when common sense would work fine. I guess we need to worry about 80 year old grandmas who don't want to open the door on a load center.

 

[fishbomb]

They burn 2-3 gallons per hour no matter if you have one light or several. Just get one large enough so not to over tax the system. For example if your on a well, the well pump, and refrigerator both kick on at the same time and you decide to blow dry your hair, that's a lot of draw and even a 10kw would have trouble handling that load not to mention lights, heat/ac, and other house needs. Just have a reputable dealer come and give you a quote. If you we're in nh I could help since I work for the family generator company and we are a generac dealer. Do your homework and don't buy from a box store like Home Depot or lowes. Whether its kholer, generac, Briggs and Stratton or another brand make sure it's sized correctly and by a licensed installer. As for son, I'm sorry to here that you had a bad experience with generac. Remember it's a machine and they all require proper maintenance. Set up, and installation. So don't bash a brand just cause you had a bad experience or dealt with a bad dealer. We could have helped you.

 

[CNGsaves]

Just a personal opinion, but I would (will) stay away from Generac. I had one (8KW portable) that worked fine for a little over a year, then it just quit. Gen output dead, engine ran fine. The local Generac service center could not repair it without replacing the entire generator head, they could not determine where the problem was . . . . . .

The OP sounds as if he's pursuing a STANDY Generator that is more of Permanent Generator setup on concrete pad in back yard near the main electrical entrance . . . ie with underground electrical service hard wired to main panel utilizing ATS (automatic transfer switch) on the Generac.

Those portable "Generac" generators are much LESSER in quality in my opinion than the permanent Standby Generac generators on a pad. The portables may just be "re-branded" some other manufacturer.

Only knock I've heard on Generac Standby generators are that ATS is proprietary to Generac so they won't let you mix and match other brands . . . thus Generac standby generator will "need" a Generac automatic transfer supply. Thus, don't buy a Generac ATS on Ebay thinking it will work with other brand standby generator.

 

[RKA]

That's probably assumed, I think the rub is Generac and their authorized service centers flat out failed him, which leads to questions about how they might handle a failure of one of their "better" standby units.

 

[Jsf721]

I called a few references of the person who is most local to me and one is even a freind of my sons. He has the 20KW ATS. He gave me an open invite and I will go over Saturday to look it over. He was very happy with the Install and the service. He changed his own oil during the storm as the lightindicated 200 hrs of run time. He said the only reason he knew the power was restored was that the lights flickered.

His system is set up that when the power goes off the systems come up in a set order and it take 7 minutes to get full power. Lights are auto matic then, pumps, heat/AC, kitchen appliances 1 by 1 and so on. He told me his load test reccommended 15-18KW and he went with 20KW for about 800.oo more becasue it came with the ATS insteads of paying a few hundred for it.

 

[nehog]

I thought about a backup generator like that but my street doesnt have gas lines and I dont want to have a huge propane tank in my yard. Im planning to go with a diesel set up in the spring. Plus they run at half the RPMs.

1. Consider a buried propane tank! They are common around here, almost invisible (except for the fill 'station' on the top of the tank) so no one knows it is there once the grass grows back!

2. RPMs: fuel is not the factor. Virtually all larger (15 KW and bigger) are going to be 1800 RPM. Don't even think about a 3600 RPM generator, you won't be happy!

 

[frankush]

I prefer the Kohler gensets myself. I think it's a better unit all around. I went through Generac factory service training and I wouldn't spend big bucks on one. The quality is lacking.

 

[mikester]

1. Consider a buried propane tank! They are common around here, almost invisible (except for the fill 'station' on the top of the tank) so no one knows it is there once the grass grows back!

I thought about a buried tank but theres a few problems with that. The area where the generator will be going isnt wide enough. If I try to go further back in the yard Ive got the cesspools in the way. The other thing is the cost of the tank. Big $$$ where I live for a good size tank.

 

[davidlee]

I have a 23KW diesel and I love it. I bought it back it 1999 and have used it for outages caused by hurricanes. I have 11 tons of a/c in the house along with the normal household load and the unit handles it well. I do not have an ATS and really have not missed it. My unit burns approx 1 gal per hr at full load. It has a 40 gal belly tank and I have a 55 gal saddle tank from a semi that I use when necessary. I have a small 12v diesel transfer pump to get the fuel from the saddle tank to the belly tank. When hurricane Ivan came I also filled a 55gal poly drum with fuel. It is slab mounted behind the shop and you can't hear it run while in the house.

 

[Helix]

Howdy all. New member here. Thought I might weigh in since I work on generators (Generac mostly). I'm factory certified and I hesitate to work on portables. I don't really hold them in the same class as permanent standbys.

Regarding Generac residential ATS's (RTS's). All sensing is performed at the residential genset compared to at the ATS like on larger units. RTS's are only controlled via a transfer circuit to activate the contactor. Some creative wiring would allow use of a RTS with another brand generator. Although that is likely beyond the scope of most homeowners. Commerical/Industrial ATS's are worlds apart from the RTS.

RPM. All Generacs are 3600 until you get up to 22kW. That also coincides with a change from air to liquid cooled. Kohlers seem to make the change around 15kW.

Fuel. If the gas station is closed during a prolonged outage, where will you buy diesel (assuming you can't store much onsite)? It's pretty hard to beat NG for reliability of service and operating cost. It's only downside is it has the lowest energy content of the commonly used generator fuels. LP is nice, but then you're reliant on the propane company for delivery.

Whatever you buy, make sure the plumber does not undersize the fuel lines. That's my largest headache at startup time. Plumbers who can't read a piping table.

 

[RickP]

I have a 15kW Generac (LP gas) purchased from HD and installed by an electrician. We've been very happy with it and it's gotten us through a couple of extended power outages without any problems. It came with an ATS, which I would definitely recommend. You can always flip the generator switch over to "manual" mode if you prefer. This model was the biggest air cooled unit I could find 7 years ago, and the price jump to liquid cooled was almost double at that time. Here's a link to the current $3,292 version (HD Model # 6240):
http://www.homedepot.com/Generac-Power-Systems/h_d1/N-5yc1vZbr0/R-204006869/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051#.UR64Jx1tj4I

We did have one repair in the first year that was covered by Generac's warranty. Because it was purchased from HD, we found it difficult to find a repair shop that would service it. So I'd recommend buying it from a business specializing in generator installation and repair. You might have to spend a little more up front, but it will be well worth it the first time you need service or repair.

I wouldn't recommend trying to power your whole house -- just make a list of the circuits you really need during a power outage and use extension cords for everything else (try to power at least one outlet on each floor). Focus on the essentials: heat, water and food. Our older Generac ATS has room for 12 circuits, so we power these:

1. Furnace fan (110v circuit for a propane furnace)
2. Well water pump (220v counts as two circuits)
3. Water heater (220v counts as two circuits)
4. Refrigerator
5. Stove (110v circuit for a propane cooktop)
6. Basement outlet (sump pump, Verizon Fios, alarm system)
7. Lights in kitchen
8. Outlets in study (for computer UPS)
9. TV/DVD in living room (long power outages get really boring)
10. Lights/outlets in master bedroom/bath

We lost power for a week after the Derecho that hit the east coast last 4th of July, and of course it happened during a record heat wave. So I wished we could run the A/C unit instead of the water heater... but if we lost power during the winter, I'd be happy to have hot water instead. You're in luck though, because it looks like the new Generac ATS has room for 14 circuits, so you could probably power both!

Good luck with your purchase -- let us know which one you choose.

- Rick

 

[theoldwizard1]

It's required by the NEC, 2008 version, if I recall. With an ATS the generator is required to be sized to the connected load, UNLESS load shedding is used.

I have seen ATS with built in "load shedding" for things like A/C, electric stove, electric water heater and electric dryer. Good idea.

So how does one determine the "size of the connected load" ?

You can buy a 125A load center with 32 slots. In theory, those 32 slots can draw a lot more than 125A. So if I feed those 32 slot via a 30A interlocked auxiliary breaker and generator, what is the difference ?