Backfeeding with a portable generator - REAL safety concerns???


Nope, this is probably the least sensitive, since the first thing the power supply does is convert it to DC, pump it through a 20kz ocillator and turn it cack to DC. The range of voltage and frequency for a switcher power supply is very wide. The monitor is more sensitive but they still are designed to be 50-60 hz so they can be sold in Europe. I have pentium "desktop" machines running in all of my cars as MP3 players on the cheapest 135w inverters I could buy and the wave form out of them is scary.
3 years, 130f ambients from the Florida sun and being turned on and off with the key hasn't killed one yet.
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In Re: Backfeeding with a portable generator - REAL safety concerns??? on Fri, 10 Sep 2004 23:09:36 GMT, by Friday, we read:

It depends on the type and quality of AC current from the genset. Usually, small generators (under 6K) deliver poor quality.
The solution is to use an Uninterruptiple Power Supply (UPS) between the genset or house current and the computer. The UPS takes in juice to charge a builtin battery. This battery then feeds the computer and ensures a clean, constant energy source and gives you a chance to power down normally when the electricity stops.
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Strabo wrote:

This is exactly what the little honda 1K and 2K generators do now. Generator feeding DC to an inverter. Quiet, light, and very clean power. Pricey but well worth it. I just wish that they made a larger size one.
--Dale
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Dale Farmer wrote:

Honda builds a five and seven thousand watt inverter models for home emergency power. Both have electric start and can be started automatically. -- Tom H
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Dale Farmer wrote:

<snip>
Honda EU3000is: http://www.hondapowerequipment.com/ModelDetail.asp?ModelName=eu3000is
Two EU2000i generators can be paralleled to double the output. I'm not sure about the EU3000is.
R, Tom Q.
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i don't know about the power co. guys up there, but around here, if you can't show them a transfer switch in your lit house, you may be out of electricity for a loooonnnnggg time. they'll pull the meter for you. <G> and you'll fight like hell to get it back. if you think it's expensive to install a transfer switch, wait til they require a complete re-inspection of your electrical system, and nit-pick it to death. you'll wish you had gone to home depot and bought a small (60 amp) switch and had it wired in on your essential needs. no, i don't work for the power co. but i know some who do. i put mine in. good luck, sammmmm

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SAMMMMM wrote:

I was gonna suggest he trade the 5KW unit in on one that will power his whole house. He's gonna need it when the utility shuts him off.

<major snip>
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Check out http://www.justgenerators.co.uk/pages/powertransfer.htm
This gives you some data.

Life in prison for manslaughter / negligent homicide if you get it wrong and the fact that you will have destroyed a life and probably a family.
N
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Safety verses cost is always a factor. If 50,000 people did it your way how many do think would die? You might get by, or you might get someone killed. Is it worth the risk? If that somone is child of yours you might consider the value of installing a transfer switch using an insured, licensed, and bonded contractor.
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Yer an idiot. What do you think supervisors do in an outage? They drive around look for damage and priortize work for line crews. When they see you house with the lights on they know that you have a generator. They may or may not know you have a transfer switch. They'll be back to check. As someone else noted you'll be in the dark for a while untill they wre convinced it's done right. If you do hurt of kill someone most power companies in concert with the union will prosecute you vigerously. If you don't go to jail you may be bankrupt. It's fair, if they can keep terminally stupid people so poor they can't afford a house or a generator they may save someone's life.

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Now that's an answer. Thanks
--
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The BEST answer is to FIX the grid so it will NOT go off!

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will
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If you always do what you say you will do NO PROBLEM. Invaribly when there is a problem it is caused by someone who knew what they were doing, they had it all planned out, they just made a mistake and property or life was damaged. While you may be willing to take this risk should some poor linema working out in the cold have to unknowingly take it too.
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Point well taken. I think I'll opt for a switch. Or simply extension cords, splitting my boiler-pump/thermnostat feed with make and female plugs, then simply unplugging the furnace completely from the (house) supply and plugging it into an extension cord. Thanks for one of the very few intelligent answers.
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<snip>

<snip>
1. Generator runs out of gas while you are out of the house. Lights go off. 2. Your hard-drinking Uncle Ernie is visiting. He troubleshoots problem. "Hey, lookit this! The main breaker was off!" Flip! Nothing happens, and he passes out. 3. You come home, refill generator, and start it. 4. Utility lineman, working on the downed power line a mile away, gets fricasseed.
In other words, you are setting a booby trap that can be set off by *anyone* who visits your house during a power outage. Maybe you won't forget, but can you guarantee that none of your friends, relatives, or neighbors will turn that breaker on?
Remember that those linemen have relatives, and those relatives may have guns. If they don't, then plenty of people will cheerfully loan them guns.
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I don't have visitors up here, but that's a valid point.
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A couple points come to mind.
1. If someone else's life is not worth the few hundred bucks it would cost you to do this right, then its likely nothing anyone can say will change your mind anyway.
2. The reason for the transfer switch is so you don't have to rely on someone remembering to turn off the main when the lights go off, and you are scurrying around to get your generator running.

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I that were the case, I wouldn't have bothered asking. I didn't ask anyone to "change my mind." I didn't even say I was going to _DO_ anything. I asked questions.
Thanks for nothing.

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Friday wrote:

The truth is that no professional will risk their reputation by advising you to go ahead with your plan.
You've got a pretty good idea of what the risks are. You want to chance it, you're on your own.
P.S. While most professionals reading this newsgroup are bound by ethics not to advise you to pursue your plan, there are some that are obliged to report to the proper authorities should they discover the existence of such a situation. Or they might BE the proper authorities.
--
Paul Hovnanian mailto: snipped-for-privacy@Hovnanian.com
note to spammers: a Washington State resident
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I seem to average one 4-14 hour power outage every other year. Other than that I loose power 3-5 times a year for less than an hour.
With those kinds of outages, I couldn't justify the cost of an industrial generator and a professional panel install, so I bought a post y2k returned Coleman generator at Home Depot and came up with a DIY solution.
I'm cheap, but I wouldn't take the risk of backfeeding the whole house. I run the 20a 240v output from the generator into my basement. There I split it into two 120v feeds. One 120v feed powers a twist lock outlet next to the furnace. The other 120v feed powers four outlets at the top of the basement stairs.
I put my furnace on a 120v twist lock plug and put a twist lock outlet on the existing furnace circuit. In the event of a power outage I simply unplug the furnace from the grid and plug it into the generator plug.
My fridge, TV, dish network receiver, and sump pump are within 20' of the four outlets at the top of the basement stairs. The sump pump is normally powered off an extension cord into a ground fault outlet at the top of the stairs, and two extra 25' extension cords are hanging on the wall.
Its not an automated solution, but as long as I don't fall down the basement stairs in the dark, it seems like a safe solution.
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