Generators and Back-up power

We have an rural machine shed (100 amp single phase) mostly used to store
farm vehicles and also is our workshop where we have the mill, lathe,
welder, etc. It is prone to power outages more and more these days and at we
seem to be working in there everyday so it obviously becomes very
inconvenient when the power is out. As it turns out, we are one of three
properties in a rural area that has "easily tripped" power. We are always
the first to lose power, and the last to get it back up. I'm not sure what
they call it, but the part they always have to fix is on a power pole a few
miles up the road from us, and it looks kind of like a paper clip. Anyways,
usually the power flickers for a bit, then poof, it is off until they send a
service truck out to repair it.
So last month we bought a 7500 watt generator to make life smoother and at
least keep the heat and lights on Here is where my question comes in. Some
of the people around here say you can go to the breaker panel and turn off
the main breaker (from the grid) and make a "cheater plug" to back-feed the
breaker panel thru a 240volt outlet (of which we have several "welder" plugs
that would be ideal for this). What are the thoughts of the group to do
something like this? I understand it is a shortcut, but if one was sensible
about it is this a viable temporary option over the "transfer switch" the
local electrician wants 1000 bucks to install?
Thanks in advance to all helpful posters, Ryan
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A bad idea Ryan. Way bad. You can buy and install your own transfer switch for lots less than $1000.00 if you are able to wire up a plug. My neighbor wired his up the cheater way. I told him this is really stupid, someone could get shocked. Months later, he is at work and his wife calls me to start the generator because the lights were flickering and she wanted to be ready. When I got there the cheater cord was not plugged in to the generator. She said it wouldn't fit. I looked at the end and one prong was bent in a little. I grabbed this prong to bend it back and got one hell of a jolt. Seems she had already plugged the other end into the 220 volt receptacle on the panel. I should have checked but it didn't occur to me that anyone would plug the cord in when there was power. If she had been able to get that plug into the generator it would have ruined it. I could have been killed by stupidly grabbing a prong that I assumed was dead. And I know better. My neighbor's wife doesn't. And my neighbor had told his wife how to hook everything up. She just didn't get it. And if the power is out and someone hooks up your cheater without throwing the main breaker first your generator might be hooked up to other houses or it might electrocute someone working on the line. Save yourself a headache and do it right. I'll bet you could find a transfer switch on ebay. Yup, 88 items found. Harbor freight has one for $340.00. Twelve circuits. Item 90813-0VGA. Also see item 38521-4VGA. This will also work for you and is $260.00. Cheap insurance against someone getting killed. And cheap insurance protecting your generator. Eric R Snow
Reply to
Eric R Snow
As Eric writes the cheater plug works but is an easy way to kill or be killed.
The cheapest and most useful transfer setup, IMO, is the 60 or 100 amp single circuit style that consists of a small subpanel with a pair of interlocked 240V breakers. Flip one off and the other on to switch from utility to generator. The interlock prevents both from being on at the same time.
You use this style by installing a separate subpanel next to the main panel and moving the circuits you want to be "backed up" to the new panel, then installing the manual transfer switch between the main and subpanel. You then arent' limited by the circuit mix of the (overpriced) GenTran style switches - like the lack of 30 amp circuits.
The attraction of the GenTran switches is you just feed this bundle of wires into the existing panel and make connections with wire nuts.
A pricier alternative to the interlocked-breakers switch is a "double throw" disconnect - looks like a regular 60 or 100 amp disconnect switch except it has two "on" positions. They are expensive retail but can be found on ebay.
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The other problem with the cheater plug method.... if you forget to throw the main breaker, and the power comes back on, your 5 KVA verses the electric companies 5 MVA is not a fair fight...... -- Jonathan
Barnes's theorem; for every foolproof device there is a fool greater than the proof.
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Reply to
Jonathan Barnes
Toolbert wrote: (clip) The interlock prevents both from being on at the same time. (clip) ^^^^^^^^^^^ That is a very important requirement, both legally and practically. When I first set up my generator, I solved the problem by buying a heavy twistlock connector, and inserting it into the power line between the meter and the house. I wired a cord with a matching connector, which brought the power from my generator to the same location. In order to plug the generator into the house, it was necessary to unplug from the utility. In order to reconnect to the utility, I had to unplug from the meter. No way could they be hooked up at the same time, and the plugs were designed to minimize any possibility of touching a "hot" prong.
Costco, for a while, was selling an overpriced setup, with wattmeters and several double-throw circuit breakers, which is more convenient. They evidently didn't sell well, because the price kept dropping. When it got down to $60 I bought the next to the last one they had, and it working really well.
Reply to
Leo Lichtman
Well Ryan, everyone is telling you that this is such a bad and dangerous idea. I hate to buck the trend however, I've done it and it worked fine.
I'd really like to have a system that automatically kicks in when the power fails and we all know that that is the right and proper way to do it. But when I got the generator the power was out so I cobbled up a double ended plug in order to turn the lights on. So far I haven't bothered to go back and do it right.
Don't tell anyone.
George. (Living on the edge)
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Of course it works George. That's not the problem. Lot's of people do risky things and get away with it. Just depends how much risk you are willing to take and how much resposnibility you are willing to bear when your risky behaviour impacts others. ERS
Reply to
Eric R Snow
You've also got to make sure that nobody else who doesn't understand exactly why it's risky knows about the cord.
You'r away.
Power goes out. Relative/friend/housemate/SO wants to run the fridge/waterbed/fishtank and tries to get the generator running. Do they know that they must turn the breaker off, and just how dangerous a suicide cord can be? Will they remember what you've told them in 3 years?
Reply to
Ian Stirling
If not they will learn fast.
Poor memory punishable by pain. Like the indians said, tell a kid a thousand times not to walk into the fire. Let them do it once, and they remember forever.
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Reply to
jim rozen
There are three issues here: 1. money 2. safety 3. liability
The "right" answer is the transfer switch. From there it's only a matter of cost. If you found someone to put in a transfer switch for $10, it would be done already. The electrician is billing you for 3 things - labor, materials and liability. Two of those you can do for yourself. Purchase the equipment and install it yourself. The third item is liability. Get a licensed electrician to sign off that it's properly installed.
Reply to
Tom Kendrick
If you buy these new, look for the GE brand. I put in a 200Amp switch in front of my breaker panel and it runs in the $300-400 range. The next closest price was around $700. Seems ridiculous for basically a knife switch in a big empty box, but there you go. Since you only have a 100A box, you could go for a smaller one. The price seems to go up exponentially with amperage ratings so even a new one would probably be around $200. For smaller setups, the GenTran switches are the way to go. You can probably find one cheap on e-bay.
Think of it as insurance. If anyone gets hurt or killed when you're backfeeding your panel, the cost of the switch will pale into insignificance. It's also way more convenient.
Reply to
Paul Amaranth (Paul Amaranth) wrote in news:
Not to mention, if the Electric Co. notices your backfeed plug, with no interlock, it is HIGLY likely they will cut your power off (pull the meter), as this is a huge safety no-no. You will be out the cost of an electrical inspection, and a reconnect fee, and any other costs they want to charge you before you can get power again. They don't want their linemen getting killed while working on a line that is supposedly dead.
Reply to
Heh. The last time there was a power out, you could not find a single rep from the power company for miles around. If they had showed up, there would have been a mob scene lynching.
They deliberately brought our area's power down to load shed, for 'a few hours' so they could bring up the ritzy areas. 'A few hours' lasted about 20.
I think the cops probably would have helped throw the ropes over the lamp-posts.
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Reply to
jim rozen
"jim rozen" typed
That is TOO TRUE Jim! If a fine representative for the power company ever came onto my property during a power outage, he'd be too busy dodging the airborne barrage of whatever the hell I could get my hands on to see any impromptu wiring! Over the last 6 years we have had 17 outages lasting more than 1 hour each time, and they are all in the last 3 years since a new company has taken over "rural" service.
Anyways, thanks for the chuckle Jim!
And thanks for all the insightful replies folks... I agree that doing it the safe way is superior... just looking for some feedback. I did a search for the GenTran as a few of you mentioned it, and saw the way it is wired... maybe I read it wrong, but it looked like you had to wire up the items you want to power up individually. I thought you could just power the entire breaker panel, then shut the breakers off on the circuits you are not wanting to use. Ryan
Reply to
What my Dad has at his house in Maine, which is blessed there, is a setup with the generator fed into the breaker panel (by a breaker of the generator's rated size) next to the main breaker, and there is a metal part (interlock) between the generator breaker and the main breaker which does not allow both to be on at the same time (I'm reasonably sure it does allow both to be off, however).
Check with the electrician who you will pay for inspecting whether this is legal in your area. It should be cheap - the interlock part is just a metal stamping which turns one breaker off if you turn the other breaker on, whcih pivots in the middle.
As opposed to a manual transfer switch, this has to be a lot cheaper, just as safe, and it does allow choosing which loads to power from all loads connected to the panel by flipping their breakers. I don't know how widely this simple interlock system is accepted (no reason it should not be other than lobbying of the authorities by people selling overpriced transfer switches). People who want to sell overpriced transfer switches should stick to selling the automatic sort, IMHO.
Reply to
Good advice! I bought a transfer panel at a local hardware store. It is the sub panel type with 2 interlocked 60 amp breakers in it. It was made by Square D and cost me 70 buck brand new in the box, including the 2 60A breakers. Will transfer 4 120v circuits (8 if you use the "duplex" type breakers).
Way cheap insurance and piece of mind.
I can go look at the Square D part number, if anyone cares to know.
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I spent a week setting up a computer system & training users in Sana'a, Yemen. Losing power for 2-3 hours in the workday was normal. I heard automatic weapons fire at night but never an emergency siren the whole week. Broken sewage pipes, bribing policemen so your car would still be there when you came back from the market, filth & poverty everywhere, cancelled excursions because of kidnapping & worse threats... I was so happy to get back to the good ol' U.S. of A!
17 outages in 3 years needs to be improved, I agree. My neighborhood goes down so often my computers have UPS's. But my gratitude for our system is much higher now.
-- Mark
Reply to
Mark Jerde
Yes Ryan, you can do it that way. It is the cheapest of the safe ways. I know money is tight but consider this: if all the things you want powered are wired to both panels then it is real easy to avoid overloading your generator. Of course, you could post a list next to the breaker box so that anyone can turn off the correct breakers. And even though you know the system real well others might not pay too much attention. I don't know your situation but if money was really tight I'd do like you mention above and hope that everyone that who switches the power follows the directions. Just make sure that whatever you do there is no way that your setup can back power the line or allow line power into your gen set. Cheers, Eric
Reply to
Eric R Snow
George wrote: I hate to buck the trend however, I've done it and it worked fine. (clip) ^^^^^^^^^^^ George, during the first power failure after I bought my generator, I was not prepared, so I hooked up using my jumper cables. We had lights. But, I was taking a risk which I would not suggest to anyone else, and, as soon as I could, I switched (accidental pun) to something better.
Reply to
Leo Lichtman

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