View Full Version : power outages and generators connections?

Joe Mioux
01-31-2008, 9:35 PM
a couple of days ago, we had a power outage. so I went to the business and picked up my 15Kw (60 amp) generator.

I figured I could back feed the power from my 220 outlet in the garage into the house. Unfortunately, it took a bit of doing to get the correct plugs to fit into the outlet.

and yes, i threw the maine 200amp switch in the main box prior to back feeding.

I got it working, and I know I should not do it that way, but I wanted to get some power in the house that night.

Anyway, now I want to add some sort of transfer switch or somesort of subpanel where I can flip a switch and power up the essentials appliances, heaters, lights etc.

I want to feed off the main panel, with this "subpanel" and then cut a whole in the wall and place a water prooff box with either a long extension cord and plug coming out of the box, or provide a long "extension cord" with a female end from the generator to a receptacle (male) inside a waterproof box.

I do not want a two plug extension cord for the obvious reason that if I or someone else plugged such a cord into the running generator, I would have some hot leads on the other end.

Any ideas (which means most cost effective ((which means cheap)) ideas) on how best to accomplish this task? Brands of transfer switches, supbanels etc? how many circuits could I run in a normal house off a 60 amp generator?

any help is appreciated
thanks joe

Bryan Berguson
01-31-2008, 9:50 PM
The cleanest way to do it is with a meter base transfer switch like this: http://www.electromn.com/res/html/transfer.htm

It would power your entire panel so you wouldn't have to choose which breakers you turned off, just as long as you don't turn on too much.


David G Baker
01-31-2008, 11:07 PM
I just recently finished installing a generator setup. I went to Home Depot and got a manual transfer switch made by Square D. The box I bought was for a 60 amp setup. The box cost me $109 with the transfer breaker switch. I added a 30 amp 220volt breaker, and 2ea 20 amp 120 volt breakers on the output side. I mounted the transfer switch next to the main breaker panel. I installed a 60 amp breaker in my main panel to supply the transfer switch and wired it with #6 coper wire. I have a 30 amp sub panel that I use for my well, refrigerator and a couple of wall plugs in my kitchen that I hooked to the 220 volt 30 amp breaker. One of the 20 amp breakers supply my furnace and the other to power my freezer and a couple of plugs in my basement.
All of the areas that I supply power to are wired directly through the transfer switch. This frees up several breaker positions in my main panel for extra circuits.
I ran about 70 feet of #8 3 with ground in conduit to the generator plug in area.
I then purchased 50 feet of #10 3 with ground extension cord made for generator hook up and added the necessary plug fittings. The wire and fittings were the most expensive items.
Many people in rural areas of Michigan back wire their homes during power failures but it is not a recommended practice.
The Square D Transfer switch has wiring instructions that are easy to understand.
You can spend as much money as you want and get all kinds of automatic switches but I don't feel that it is worth it in my situation because power does not fail that often and when it does it is not for too long generally. I would go auto switching if I was away from my home for any length of time.

Lee Koepke
02-01-2008, 8:51 AM
I am not an electrician, nor an expert, BUT .... FWIW, If you backfeed like you stated in your original post ( thru and existing outlet) you run to potential to cause problems upstream.

what i mean is, if there are downed power lines, and you backfeed, you could theoretically be feeding these downed lines. If the local authorites are trying to clean up / repair, they could be in jeapordy.

Its what I have been told, but I tend to do / recommend doing things they way they were intended. Back up generators are intended to be installed with a transfer switch that prevents backfeedin into unwanted circuits for safety reasons.

Matt Meiser
02-01-2008, 10:26 AM
Shutting off the main breaker assures that you won't backfeed. Still not the recommended way, but if the main breaker is off there's no danger to the line workers.

Lee Koepke
02-01-2008, 10:36 AM
Shutting off the main breaker assures that you won't backfeed. Still not the recommended way, but if the main breaker is off there's no danger to the line workers.
thanks for clarifying.

my info came from some lineworkers during the tri-fecta of the florida hurricanes a few years back.

John Newell
02-01-2008, 12:16 PM
In installed a Gen-Tran switch years ago. Installation is simple, though local code may require a licensed electrician.

My take on backup power is that it's for emergencies...keep the oil burner and circulators running, keep the fridges/freezers cold, etc. - not for general convenience. That allows me to use a very portable 3.5kW generator, which has another advantage: reduced fuel usage.

Fuel - type and amount are big considerations. NG or propane would be best, I guess - not a realistic option for us. Diesel would be next, but diesel generators are usually BIG. That leaves gasoline, which presents real storage issues - flammability, need to stabilize, etc.

Steve Clardy
02-01-2008, 12:30 PM
I used a twist lock plug on mine.

Female plug is hanging out the bottom of the main pole box.
Its hooked onto the bottom of the main breaker.

I shut the breaker off, then hook the gen cord up.

My gen cord has the male end on both ends.

Chris Padilla
02-01-2008, 12:59 PM
I just plug in my back-up generator thus no need to worry about gas lines or oil or storing/stabilizing gasoline. There are also no noise or space problems, either.


John Newell
02-01-2008, 2:40 PM
More thoughts I meant to add in my first post.

As we all know here, motors draw a lot more power on start-up - you may need extra headroom on the generator when you size it.

Most of these are not really intended for continuous use - consider spare parts.

Make sure you "exercise" the generator a couple of times a year.

Most generators (there are exceptions, especially in newer ones - mine is 10 years old) provide pretty cr@ppy power. I fried a microwave once trying to run it off a generator.

David G Baker
02-01-2008, 5:41 PM
I spent the bucks and got the Honda 6500 watt generator that is stable enough to run a computer.

Brian Elfert
02-01-2008, 8:56 PM
I went whole hog and bought a Kohler standby generator that runs on natural gas. It has an automatic transfer switch and start automatically when power fails. I installed a seperate subpanel for circuits powered by the generator. I installed this during construction of the house so I have certain lights, outlets, and the furnace on generator along with a few other things.

The generator is 7,500 watts on natural gas and cost either $4,000 or $5,000 not including installation I did myself. It turns out my central A/C draws less than 20 amps so I could have hooked it up too. In an outage during a heat wave I could easily move the breaker over and wire up the A/C.

I got the generator because of some major storms that had hit the area in recent years plus the extremely water table that requires constant pumping by my sump pump. Of course, it has only run twice in 6 years and neither was a major outage.

There are lots of really cheap whole house generators out there now. The biggest expense is likely the installation if you can't do it yourself.

Joe Mioux
02-01-2008, 9:43 PM
My gen cord has the male end on both ends.

That is basically what I had the other night. Common sense tellsus not to walk around with a Hot male end in our hands. ;)


Joe Witts
02-05-2008, 9:29 PM
All good ideas! I would add that whatever way you choose to hookup your subpanel/transfer switch - make sure that you double up the ground either by adding another ground rod tied directly to the subpanel or using bare copper wire tied to you copper plumbing. If you use an actual 3 position manual transfer switch - you don't have to worry about backfeeding the grid if you forgot to kill the main breaker!


Dennis Peacock
02-05-2008, 11:33 PM
Yup, I've done that several times before and works good. Run a cord from the gen to the plug and crank it up. Works good. I gotta buy me a permanent generator one of these days.

Wade Lippman
02-07-2008, 11:24 PM
That is basically what I had the other night. Common sense tellsus not to walk around with a Hot male end in our hands. ;)


But if you plug it into your outlet first, it is not a hot male end. Assuming you are using a transfer switch (or have actually opened the breaker).

Steve Clardy
02-08-2008, 9:21 AM
That is basically what I had the other night. Common sense tellsus not to walk around with a Hot male end in our hands. ;)


So true :D

I plug it all in before starting the generator.

I'll get one of the gen box switches probably next year.