Generator qwestions---we had serious power outage!!

[George2615]

TractorLegend,
You mentioned you have a garage with compressor. I have a garage with a 220V compressor, 220V 2 post lift, and all the other garage tools. House has 110V oil furnace, 2 window AC's (1-220V, 1-110V), 220V well pump, 120V washer & 220V dryer, plus my 110V coffee pot. I bought a 10K 20HP Miller 250NT welder generator for under $2800. My generator is plugged into a 50A breaker when running the house.
It runs my entire house with AC's on, drawing water from the well, and the dryer running, plus any lighting I need. If you get a 10-15K generator, I don't see any problem running your house and garage.

 

[rlk]

This generator Guardian Air-Cooled Standby Generator 9 kW (NG)/10 kW (LP) Dual Fuel, Model# 5241 |Residential Standby Generators | Northern Tool + Equipment , also from Northern Tool, may be better suited to the application you describe. It is not tri-fuel, but it is automatic, includes a transfer switch, and produces 75 amps @ 120 Volts on natural gas.

CurlyDave provided a good link to Northern Tool for a Guardian 9 kw Natural Gas or Propane generator. You can get some good information from Northern, however, their prices are not the best.

I just purchased a Guardian 16 kw Natural Gas or Propane generator from Ziller Electric My price was a couple hundred less than what is listed on Ziller's web site and includes a transfer switch and shipping to your home.

The price for the 16 kw generator was only $200 more than the price Northern has for their 9 kw Guardian generator.

My electrician charged about $800 to connect everything.

Bob

 

[CurlyDave]

You can get some good information from Northern, however, their prices are not the best.

I completely agree, and I am somewhat embarrassed for not mentioning this fact in my post.

I have used Northern to check out a lot of tools and generators, but after doing price checks I have never bought a generator from them, just because their prices are not the best.

The best deal I have had on a generator was a 15 kW (continuous) Generac from Home Depot.

At the time I got it, it was $1999, and there was an on-line coupon for 10% off, so it was $1800 delivered, which is a really good deal. Especially considering everyone else wanted an extra $250 to deliver to either CA or OR.

 

[Buckeye_Jim]

....Whats the big deal with turning off main breaker and powering your house with a generator through a 220 50 amp plug in (like a welders) and just choosing certain breakers?? as opposed to the transfer panel.

I admit this can work. The reason code calls for the transfer switch is for safety to utility workers. If for instance you weren't around and someone else was configuring your panel, utility workers could be exposed to a dangerous situation. With a manual or automatic transfer switch, you have everything setup ahead of the power outage in a safe manner.

Jim

 

[RonMar]

I believe there are also several manufacturers of approved interlocked panels. The panel has a mechanical slide bar that prevents both the main breaker and the breaker used to backfeed the panel from the genset from being energized at the same time. Check out Gentran Corporation: Generator Transfer switches for home & business They market interlocked main panels that replace your existing main panel.
They also sell add-on panels so you can make some of your circuits dual fed either from commercial power via your existing breaker panel or the genset. The add-on panels come pre-wired and include a generator interconnect cable. Pretty simple DIY installation for someone who knows their way around the inside of a power panel and an absolute cakewalk for a liscensed electrician. The prices don't look too bad either.

Full-on backup power is going to be a tall order if the majority of your appliances are electric, and not particularly efficient as the genset needs to be sized for the peak loads(electric dryer, electric water heater, oven/stove, microwave) or combinations of automated loads and be way underused at almost any other time. For instance my typical evening house load is around 1KW with an occasional peak near 2KW depending on if/when the freezer, refer and well pump cycle. That is with a pellet stove, stereo, LCD TV and Sattelite and a few compact florescents running, oh and the computer I am typing this on. A 15KW genset would be setting there sucking down a lot of fuel inefficiently providing for my meager needs. If it isn't expected to happen very much, I would go with an add-on panel and a smaller generator. A main panel upgrade would allow you to taylor the load by selecting what circuits are powered and when. The largest draw in my home is the electric dryer at 20.5 amps @248 VAC(5084 watts) Everything else is less draw. With some creative load sharing(turn off all breakers and turn on water heater to prep for laundry or a shower), a 6KW genset could be made to work and keep you comfortable during these occasionall/rare occurences. Better still switch to gas appliances then the time on genrator power would have less of an impact.
I would say a 20HP 15KW genset is going to consume a considerable ammount of natural gas. I would definitely check that the feedline from the main to your meter is capable of handling the additinal ammount of fuel required.

Good luck

 

[TractorLegend]

You can get some good information from Northern, however, their prices are not the best.
I have used Northern to check out a lot of tools and generators, but after doing price checks I have never bought a generator from them, just because their prices are not the best.
The best deal I have had on a generator was a 15 kW (continuous) Generac from Home Depot.
At the time I got it, it was $1999, and there was an on-line coupon for 10% off, so it was $1800 delivered, which is a really good deal. Especially considering everyone else wanted an extra $250 to deliver to either CA or OR.

Thanks for the heads up---I see Home Depot is less for the same 15K watt stationary Generac w/ auto transfer switch delivered... I think 300 cheaper than Northern plus at least 300 for shipping depending on their mood from Northern...plus you can likely get 12 mos no interest from Home Depot... I would have to pay local sales tax however
Northern is cheap/ off season with their terms offers.
I'm swinging toward this idea but will get the utility or a contractor to verify my gas supply size

 

[kenmac]

The gas co. supply line to the house is large enough ( in most cases). Most of the time the gas meter will have to be enlarged to accept the additonal load. If you google generac generators you may find a lower price than H.D. There are several on line sites that sell the generac brand.15 kw is a good size . I like the water cooled 20 kw . Good luck

 

[Highbeam]

"Originally Posted by TractorLegend
....Whats the big deal with turning off main breaker and powering your house with a generator through a 220 50 amp plug in (like a welders) and just choosing certain breakers?? as opposed to the transfer panel."

I just spoke with the electrician about this last night while speaking with him about a whole house transfer switch for my panel. I don't necessarily have a problem with backfeeding a panel, there are safety and legal issues but if done properly it is very effective and very common.

A 50-amp welder plug is a three prong deal. The three prongs are supposed to be black-red-and a bare ground wire. The bare ground wire is allowed to be a very small size since in this dedicated 220 volt plug since the only thing it will do is trip the breaker. The bare ground is not meant to carry very much current and certainly not 50 amps.

So if you backfeed through this plug and power a 110 volt appliance you will end up with a big black (or red) wire as the hot wire and a wee little tiny bare copper wire acting as the white common. Since AC power is a push-pull deal, both hot and common wires should be adequately large. (I think)

Don't use your welder plug. Your dryer plug is a 4 pronger and more suitable though only breakered at 30 amps usually.

I ran my 5500 continuous/6850 peak generator for about half of the 80 hour power outage and it sucked a good bit of gasoline. It is loud too but had plenty of power to spare in my natural gas powered house.

Besides running your clothes dryer and that big honkin air compressor, your loads are very small. You could get by with much less generator if you leave your dryer off. Do you really need to do the laundry?

I just moved into an older house that needs a new panel so while the sparky is in there he is planning to install a whole house transfer switch with an input plug all legal and pretty. Just because your house CAN overdraw a 5kw generator doesn't mean you need to supply more than 5kw. So my plan is to buy one of those cheap and quiet 299$ 3500 watt (220 volt) chinese generators to run during most of the power outage. Then for extreme and uncommon power needs like welding, air compressor, or running a dryer I can roll out the big boy.

The only drawbacks to a whole house transfer switch are the cost and then not knowing when the grid power comes back on.

 

[TractorLegend]

Good thoughts!
maybe if one were going "non code" and backfeeding the panel, maybe one of those dedicated outdoor NEMA 3R generator receptacles would be the way to go.

Assuming one has knowledge of what is going on and doesn't backfeed the utility all should be well.

I too normally like watercooled engines, however for the cost increase and the reletaviley little use it would get I think the 15K watt aircooled would be good/ acceptable.

 

[Highbeam]

It would be dang convenient to install an outdoor twistlok 4-prong plug that matched the one from the generator to the outside with the appropriate weather enclosure. Adequate wire size for all four wires and a matching breaker in the home panel would be great. You would then need to make a suicide extension cord to go between the generator and the wall mount twistlok but the benefit of all of this is that you can leave your generator in the back of your truck and plug in to a good connection for the house. Everything should work as though the power is back on.

The only thing seperating the above setup from being legal is one of those panel lockout pieces shown on an earlier thread which are very low cost and apparently "proper".

I have to think that maybe those folks in Burien wouldn't have died if they had an exterior plug for their generator instead of running it in their garage.

You saw that 30HP twin cylinder air cooled 15KW genset at Home depot right? Our HD here in Bonney Lake has a big stack of them but no easily visible price tag. Looked like quite a monster.