Ice Storm

[jwax]

I know what you mean, Bob! Motor horsepower ratings are a conflict in definitions. Marketing folks take lots of leeway in defining the "power" of motors.
Anyway, here's another example of the "20 HP for around 10 KW" scenario:
http://www.northerntool.com/webapp/wcs/ ... 70_710_710

[reloadron]

OK I have read the post in the thread and I will share my own personal experiences with generators 101 if we can call it that. Our home is gas fired heat but none the less. I met my wife about 22 years ago. Her mother was bed ridden and for all purposes in a vegative sort of state. As the years passed more and more machines entered into our lives. Among the last was the ventillator and oxygen concentrator machines. I am looking at all this stuff and thinking what happens in a power failure? The result was ugly so we will skip all the medical nonsense.

I bought a simple little 5KW gasoline powered generator. The needed medical equipment and the basics of the house including furnace coule run on 4KW. The transfer involved several steps. Things did work but weren't fun. However it did work and got us along. That damn generator helped us and the neighbors through a few major power failures.

A few years ago we did some needed major home improvements:

http://www.bearblain.com/the_big_dig.htm

Though Kathy's mom had long passed we decided we wanted reliable backup power for our home. We invested in an 18 KW natural gas fired backup generator which looks like this today:



I would suggest something like that. Runs fine on LPG as well so get a tank devoted to the generator. Power goes off and 10 seconds later returns.

Just My Take
Ron

[jwax]

Ron, what is the labeled horsepower rating on your 5 KW generator installation?
I'm guessing around 12 HP?
John

[dtief]

Part of the apparent HP discrepancy is due to the way engines are rated, and the power curve. IC engines are usually rated HP at maximum RPM. Turn the RPM down, the HP drops also. But it isn't linear. The HP drops faster than the RPM.

My 3KW generator = approximately 4HP. It has an 11 HP engine. But the engine is running at less than 1/2 maximum RPM, where the HP rating is made. Also, you have to allow for less than 100% efficiency.

Dave

[FOB]

Here's my 2 cents worth. My first interest in portable power came in 1995 to power the two a/c units I put on an old school bus I converted to a camper to take to hamfests and tailgate. I bought a twin cyl. 19 HP 10KW ($2,000.00) so it would not stall if both a/c units started at the same time. It worked pretty good.....then came 1999 and the Y2K scare. I thought that if I lost power and had to use the generator, where would I get gas if the gas stations lost power also.....so I had my unit converted to use propane also, which is much safer to store than gasoline. My BEST investment that year was to buy 100 cases of Y2K BEER, and sit back, ferment, and wait for the power to quit (which it NEVER did). I started renovating an old farmhouse I bought in 2001, and ran into all sorts of problems with power outages the first several years. Three years ago I built a 10 foot square building (small polebarn) next to the pole with the transformer, installed a new meter, main disconnect (400A 600V 3PH) which I picked up at an auction for $100. A transfer switch to keep the power company happy, and 2 - 200 amp Safety switches, 1 - 100A Switch 3 - 60A Switches, and 3 - 30A switches ran power to every building on the property underground. The total cost was around $12,000 but I don't worry about outages anymore. My 10KW gen-set consumes a little over a gallon of gas per hour - last spring we lost power for 11 days after a wind/ice storm knocked down a bunch of power poles. I put 185 hours on my gen-set at $ 3.45 per gallon, you do the math. I now have a 5KW rig I run overnight to save on gas during long outages, but it does not have the ooomph to run the pump in the well.
Most people who run auxilliary power units run afoul of the power company because they do not bother to isolate their stuff from the commercial utility power. It is against the law to supply power to your house that can in any way be back fed to the power company lines. They can and will disconnect you from their service and then you will go through several inspections to get approval before they will restore your power, if they find any unsafe wiring concerning gen-sets. They really have a legitimate beef.... transformers work BOTH ways....if you feed 120 volts from your gen-set into the transformer on the pole, it can be kicked up to 13,800 volts ( or whatever your local transmission voltage happens to be) and KILL some unwary lineman down the road.
I had a good friend back in my drag-racing days,who said " Speed costs money.....how fast do you want to go?" That bit of wisdom applies to a lot of things in life. There ain't no quick and dirty way to repower your house and the easy way ain't cheap!!!! I was a maintenance electrician for many years and did my own work, local codes differ, but I can answer a lot of general questions.
Fat Old Bob

[Bob Scott]

They (power companies) really have a legitimate beef.... transformers work BOTH ways....if you feed 120 volts from your gen-set into the transformer on the pole, it can be kicked up to 13,800 volts ( or whatever your local transmission voltage happens to be) and KILL some unwary lineman down the road.
Fat Old Bob

That's a good point. I never thought of that, but I think only someone who is elecrically challenged would leave the main breaker connected to the service wiring. You can never be sure when the power company restores power and YOUR genset 60Hz AC isn't phased up with incoming power.

However I was thinking of a way to run emergency power without doing any wiring modifications. Of course, you need to know what you're doing. In a power outage you could simply turn off your main breaker and temporarily plug the generator 240V output into either a range outlet or a clothes dryer outlet, depending whether you want to pump power through the 40 amp or 30 amp breakers in your breaker panel. This way there is no permanent modification to inspect and the power company can't squawk. My main breaker has a provision to install a lockout padlock.

And, because you probably chose a generator that cannot supply as much current as your entire panel is wired for, removing one of the appliances at least disables one large appliance from drawing power. I'd use the 240V 30A dryer outlet, and run the genset cable into the house through the dryer vent.

[dyarker]

Bob, wouldn't that put voltage on a male plug? How about cut-over switch with male plug on wall for temporary generator connection. Switch in normal position connects mains to load, male on wall is disconnected. Switch in generator position connects load to male on wall, and cord from generator has female on end.

[haklesup]

A transfer switch which serves only some of your branch circuits is also possible. This is particularly easy to implement if your power is divided into a sub panel. In any case, if you don't want the cost, complexity, permits and inspections that come with a properly installed system I suggest you just run a multi-tap extension cord to the places you need it. If you don't need instant or automatic switch over I don't see rolling out a cord and moving a few plugs to be a big problem. These things generally happen much less than once a year. Can't find a flashlight fast enough, plenty of battery backed emergency lights to be found.

My plan for extended blackouts is to simply use an inverter and my Explorer to power a few lamps and a TV and get a block of dry ice or two for the freezer. Fortunately it doesn't get so cold here I need to worry about the heater but when I lived back east, our NG hot water system could be run passively by manually opening the demand valves and letting convection circulate the water. Not an option with hot air.

That's a good point. I never thought of that, but I think only someone who is electrically challenged would leave the main breaker connected to the service wiring.

I hope the electrically challenged would hire an electrician to install it. He won't forget the transfer switch else loose his license. But seriously, the consequences can be far greater than service cut off. If someone got hurt, someone else could be criminally liable for negligence. I expect linesmen would check for residual or active voltage on a line before working on it but if found it could significantly delay restoration while they search for the cause.

[reloadron]

Ron, what is the labeled horsepower rating on your 5 KW generator installation?
I'm guessing around 12 HP?
John

The 5 KW portable unit is a Coleman Power Mate with a 10 HP Briggs & Stratton engine. The unit still runs great and this past fall during a major state wide power outage my brother drove up from Columbus to Cleveland to snatch it up. There was not a retail generator to be bought in the state. He took it down to Columbus for my mom's house to provide heat and the basics. That unit must be about 15 years old. Runs great though!

Things I did very, very wrong:

1. The thing only has a 1.5 Gal. fuel tank and under a pretty full load needed refueled every few hours. That sucked!
2. No Wheels! When it was needed it had to be dragged from the shed to beside the house where I had a pony station to connect it into.
3. It was a pull start! That sucked for the wife if I wasn't home.
3. No fully automatic transfer. I had posted instructions and as was mentioned, you need to totally disconnect the mains service. Yes, transformers work both ways. It did deliver 240 VAC and I backfed it into the breaker panel. The process was disconnect the mains, go outside and connect the twist lock power cable to the pony station, start the generator, return to basement and switch the generator breaker pair on.
4. Overall it was a pain to get online but it saved our butts and a few neighbor butts a few times.

This is about what it was:

http://shopping.yahoo.com/s:Home%20Gene ... nd=Coleman

The first unit in the link. I do know that fifteen years or so ago I only paid about $500.

This is the unit we installed a few years ago:

http://www.lowes.com/lowes/lkn?action=p ... lpage=none

They modified the box a little. When we bought it it was the largest I could get without going to water cooling. I love this thing. Power goes away and 10 seconds later it is online. I have UPS units on critical stuff so we don't miss a beat. The unit does a programmed "exercise cycle" once a weel and runs about 20 min (without transfer) to maintain the battery. Also it is very quiet.

Ron

[Dean Huster]

I worked with a Coleman generator a couple of months ago and was horrified to realize that it was changing it's engine speed all over the place to compensate for load changes. That means that Coleman was regulating the voltage at the expense of the frequency going all over the charts. It may have been a little, quiet unit, but the only reason I kept on using it was that all we were running were Christmas lights for a parade.

Dean

[reloadron]

I worked with a Coleman generator a couple of months ago and was horrified to realize that it was changing it's engine speed all over the place to compensate for load changes. That means that Coleman was regulating the voltage at the expense of the frequency going all over the charts. It may have been a little, quiet unit, but the only reason I kept on using is was the all we were running were Christmas lights for a parade.

Dean

The only time I saw mine load was when the furnace would kick in. Very minor drop then right back. Overall looking at it with a counter when I first got it years ago it ran a pretty stable 50 Hz. Under normal loads that engine should run a good constant speed. When a load like a furnace blower or 1/2 HP motor under load kicks on it should dip and get right back stable. Not that Briggs and Stratton are good but this one works. They are not that fancy but then again for what it cost compared to the new whole house unit there is no comparrison.

Ron

[Bigglez]

Overall looking at it with a counter when I first got it years ago it ran a pretty stable 50 Hz.

Fifty hertz? Or, is that a typo?

[reloadron]

Overall looking at it with a counter when I first got it years ago it ran a pretty stable 50 Hz.

Fifty hertz? Or, is that a typo?

My bad, a pretty stable 60 Hz.

Ron

[Dean Huster]

Well, this was the smallest thing Coleman made, and comparing it with a "real" generator is kind of like comparing one of those little 12-volt air compressors that put out 175 psi at 0.000004 cfm (takes the good part of a day to air up a 16-inch tire from flat) to a 50-gallon, 5hp, 240v model. Connecting up a 1500-watt space heater to the thing nearly stalled it.

Dean