If so would you buy it again? How many times have you used it? Is the power "clean" or safe for long term consumer electronic use? How much did you spend above and beyond the price of the unit?

My brother put one at his house a couple of years ago in Victoria. I don't know how many KW but it will run his entire house if the power goes out (I think 25 KW). It automatically "excersizes" itself once a month for part of the day. It runs on natural gas.

I think the major expenses are: the generator(duh!), the installation, and some kind of a switchbox that keeps the generated electricity out of the electricity mains.

It will be fairly expensive and will be nothing but a convenience so don't expect there to be somekind of a payback. You will only appreciate it when that hurricane comes through and you are out of power for a week or two.

I got one about a month ago. I had been considering it for a long time and finally pulled the trigger. I ended up with a 20kw GE, transfer switch, dual low voltage monitor and a high voltage monitor.

I have to say its pretty awesome. I can set priorities to my high demand appliances so the AC's kick on first but when they are all caught up it will run my pool pumps. When it was installed and we started it up and put the load of the whole house on it, it didn't miss a beat. The more sophisticated systems today are designed to run your whole house but not at the same time without letting the generator overload. With that said mine handled the whole house (4100 sq ft) including the AC's with no problem.

It runs itself once a week for 15 minutes.

You don't buy one for the ROI and they are not cheap. I travel a lot and it provides me with piece of mind for my wife and kids when I'm gone. Estimates vary widely and you have to be careful. They are messing with your gas and electricity ago you don't want them shortcutting. I haggled with my guy and got a good price. It was about 25% lower than the highest bid from another vendor.

The other thing to consider is maintenance. It's not a lot but you have to change the oil, battery and spark plugs at various intervals. It's essentially like having a car engine on the side of your house.

How loud are they when they run.

Like others have said, the payback probably isn't there, unless you get a natural gas generator set, pay less for natural gas, and use it in lieu of your normal electrical company.

That being said, they are a great item for peace of mind and convenience when you lose power.

You can get one with a sound attenuating enclosure; it will be about 70 dB, which is about average street noise. You can google all sorts of comparisons on that.

The residential units are being packaged with transfer switches, and some are geared toward "whole house" support. That would be the way to go so you don't have to pick and choose what to support and don't have to set a separate panel and re-wire those loads to it.

Hope that helps.

Is the power "clean"? I mean will it harm a computer if it was used to power it long term (6 months)?

They aren't quiet but it's in an enclosure that helps a lot. Mine is on the side of the house and the exterior wall it shares is a one bay garage. On the other side of that is the kitchen. Unless you really focus, you can't hear it inside. Outside its loud but you can have a conversation standing next to it.

I don't know about running it that long term. Weeks would be fine, months I don't know about. I wouldn't worry about the power so much as I would the viability of having it run for months straight. At a minimum you would have to stop and do oil changes and stuff but the power it puts out is good as far as I know.

It may be fine, but I don't know.

Tell me what you mean by "clean" power.

I think the generator set should have voltage regulation to output a good, steady level. That being said, the output voltage would initially dip due to the block load that is put on the generator. I do not believe it would harm your computer. If you are concerned about voltage fluctuations, I would suggest you connect your computer through a UPS system with a voltage regulator.

If your electrical system has proper grounding it should not be a problem.

Power from a genset isn't going to cause plaque build up that one day causes your electronics to have a heart attack. Whether its fed from a genset or utility, the risk is from spikes, swells, and surges. You could make the argument that a genset provides a slight advantage because you are removed from the grid. You won't see transients from the grid. If anything, the switching power supplies in electronics are what cause harmonic distortion that plays hell with power.

Regardless of where your power comes from, put surge suppressors on your high dollar items. Lot better yo replace a $40 unit than a $2000 tv. Keep in mind surge suppressors are like bubble wrap. The components inside "pop" when thry take a hit - they don't last forever. And don't let the Best Buy idiot sell you on the hyper-expensive one because of your computer's speed or the units Joule rating. Clamping voltage is more important IMO.

Grounding, while important, will not mitigate surges or harmonics.

I added a transfer switch and connection so I could plug the genset in my RV into my house if needed. That is the "value" way to do this but that approach isn't generally going to run a 3000+ sf home because the RV genset more than likely isn't going to be sized anywhere near large enough. I use the old "Green Acres TV Show" approach with my kids. You can run things that add up to 8. The AC is a 4....the frezer is a 1 and those are MINE and MUST run. Microwave is a 1, normal lights in EACH room are a 1, etc., TV/Wii is a 0.5 so they can see what discretionary loads they need to turn on and off if I'm not there to manage it.

The biggest problem I run into with gensets when consulting is transients (spikes) and harmonics. You don't get the lightning spikes from somewhere close on the power system moving into your building with the proper transfer switch but you can get a pretty good transient spike sent to your system each time the genset is started up and then shut down when its used/exersised in the right situation. With price and design you can generally get rid of that issue in several ways. One was mentioned above by Underoos Ag. The most recent issue I dealt with was a newer commercial building (an electric coop headquarters actually). Everytime they exersized their genset they lost from 12-15% of their electronic ballasts. The intial thought of bad ballasts was shown to be incorrect when we could see a 3,000 volt transient hit the system for about 120 microseconds every time the transfer switch operated. It was a combination of bad/damaged contacts in the transfer switch AND the software in the control system that wasn't set to close/open at zero crossing (or close).

The harmonics produced from your switched mode power supplies and any VFDs (variable speed compressor, etc) usually won't have the utility neutral to bleed back onto like when you are connected to the grid....so your local system has to absorb all the harmonics and that can be problematic for circuit boards, neutral conductors and motors under the right circumstances.

Electrical Ag,

I read some info by Generac on a portable gen set and by Honda on an inverter Generator. The Generac lit warns that consumer electronics can suffer from long term use and called out lap tops, tvs, etc. The Honda lit goes out of its way on its inverter generators to tell the owner that the use of the Honda Inverter Generator is safe for the long term use with electronics.

So I am not an EE but I would guess this means that there may be spikes in voltage or some other un intended phenomenon in the current for portable generators.

The Honda inverter Gen sets are much more expensive than comparable wattage units.

The portable gen set is probably like the kind you'd take to the deer lease or tailgating, correct? If so, then yes, I could see those units not having quite the same quality as a permanent unit.

UnderoosAg - I was mainly thinking about voltage stability and reference when I made the comment regarding grounding.

EA I smell whacha cooking. That was meant more as a general note to other folk. I've run into some, um, *interesting* theories passed along by the just wanna help folks at Best Buy and HD/Lowes.

One helpful young lady described how a smart power strip magically transformed and/or made green power out of plain ol' dirty power. Which, you know, is better for the environment.

Now, Under' how can you say such things? <G>

Why, that nice PFK in the Blue Shirt was adamant that the Monster power strip was so good, it needed its own surge protection device.
(The facts that he'd never heard of IsoBar, or what a thermistor was or does not withstanding.)

Not that I've found essential computers plugged into DPCV; and coffeemakers and under-desk space heaters into the UPS, or anything like that.

To the OP's question about running "consumer electronics" of a jenny for more than four months--well, I'd worry more about the lack of infrastructure than the wear-and-tear on the equipment. If that is the need, go hire an EE and get a system designed to run that long.

Ike was a fascinating object lesson on the difference between ad hoc systems good for 1 to 48, maybe 72 hours' run time being extended to 7 to 15 days' duration. Planning is the key issue.

NG is a great fuel to use, too--especially for not having to fuss with keeping a jenny's tank fulle (and that temptation to fuel while running).

I have a 27 or 30kw Diesel generator. The transfer switch is an automatic GE/Zenith Controls Unit, but I opt to start the generator manually. I also start it manually once a month to make sure its operational. I have all of my lights and fridges hooked up to it. It will run everything, including the AC, but its not hooked up to. I have a small portable AC unit for use if my central every goes out, and it runs on 110, so I simply use that if the need arises. Fuel consumption is tied to electricity usage, so I only hook up things that I consider necessity. I don't need 5 tons of AC during a crisis...just enough to keep a room comfy. Its totally worth having...Ive used it for power outages before. Its handy. The problem is that its a 30hp diesel and burns about 3/4 gallon per hour under load @ 3600 RPM.

[This message has been edited by BrazosDog02 (edited 8/13/2012 12:18p).]

Installation costs will probably run an additional ~5K over the price of the generator and switch. Natural gas line install, electrical transfer switch install, any communication lines, and concrete pad.

There are three types of transfer switches:

A)Smart Switch which "sheds" circuits as needed. You set the priority and it cuts power to certain circuits as your house needs it. Good in theory, but I question the long term usefulness, potential for failure, and finding someone who could work on one. It will allow you to "under-size" your generator and still potentially run everything.

B)Critical Circuit. This is an "under-sized" install as well. IMO much more stable than a smart switch. The only down side is you just hook up things you need to run and size accordingly. Well Pump, Air Conditioning, Fridge, Freezer. Probably not running clothes dryer, electric stove, pool pumps, etc...

C) Whole house. Simple, whole house switch, energizes all circuits, requires 30KW+ generator. If you need to run everything, this is the way to go.

Also, for longevity and reliability of the engine: 1800RPM liquid cooled > 3600RPM liquid cooled > air cooled.

Air cooled motors arent designed to run hundreds of hours continuously, and car engines operate better/longer at 1800 rpm.