Transfer switch

[grweldon]

I'm in the planning stages of buying and implementing a backup power generator for my farmhouse.  The way The house is wired, power comes in to a pole 100 feet from the house and into a 200 Amp outdoor load center with pass-through lugs that allow you to direct the input current to another source while also operating from the load cell.  I have no circuits wired up to the outdoor load center but have used the pass-through lugs to run underground cable to my indoor load center.  I have all my house circuits wired from the indoor load center.

If I turn off the main breaker on the outdoor load center, it completely shuts off ALL power to the indoor load center.  It also shuts off current to all of the places where circuits would be installed on the outdoor load center, isolating the power from the outdoor load center.

I'm think this would serve as a safe transfer switch if I were to install a breaker in the outdoor load center and attach my generator directly to it.  The only way current could be transfered back to the power lines would be if I forgot (or someone else forgot) to disconnect the main breaker and apply a load to the load center using the generator.

Doesn't the same issue exist with a dedicated transfer switch as this?

Now that I think about it, I guess the answer is "no"  I guess with a dedicated transfer switch, the incoming power is directed to the load center either from the line or from the generator.  I guess to be fully safe and code compliant, the transfer switch has to be fed from both the line power and the generator power and can only connect the load center to one or the other, not matter what.  The scenario I proposed above does not satisfy that requirement so I would not use it as a permanent solution.

But... if I don't yet have a transfer switch installed I could still do what I explained as long as the main breaker in the outdoor load center was off... right?  It would be safe to all people and equipment as long as the main breaker is disconnected from the house, allowing me to control all the house circuits with a generator and avoid all extension cords.

I couldn't use that method long-term anyway because the power pole is not where I intend to setup my generator, but in the meantime, as far as my reasoning is concerned, this is a valid temporary solution... right?   :P

[Hilltop366]

I'm no electrician but have asked a few questions about generator and inverter backup wiring and the answer I got is there has to be no possible way for human error to accidentally put power on the grid, usually a transfer switch.

At the time all I wanted to be able to run was my wood boiler circulator (less than 1 amp) so instead of going the transfer switch route I cut the wire for the furnace  circuit next to the panel and added a single receptacle to the end of the wire and a plug to the other end going to the furnace. when the power is out I unplug the plug (disconnecting it from the grid) and plug it in to the inverter.

Another thing he said was to put only the things that you would want to run during a outage on a sub panel with the transfer switch in between the two panels, this would reduce the capacity required for the generator and in my case reduce cost of install and future service because the main disconnect is in my panel and would require the power to be shut off to change anything before the panel.

[barbender]

Grweldon, what you are suggesting would work, but could also electrocute someone working on the line What type of load centers do you have (brand)? I have SquareD, and they make a switch plate for their panels that I decided to use. It just makes it so the main breaker has to be off to turn the generator breaker on. It isn't the same as a transfer switch, the nice thing is you can use any of your circuits in the panel, instead of having pre-wired "priority" circuits like with a transfer switch. You can power as many circuits as your generator can handle, or switch one off so you can run another for a while. Hope this makes sense :

[MikeZ]

GR : My 2 cents worth. Go big if you can. About 15 yes ago had serious ice storm I think two counties affected. Could not work so spent most of day looking for gen. Wound up 3 counties away, came home with 15kv pto on little trailer. Bigger and more than expensive but have never regretted the purchase. So nice to live normal not having to worry about what to turn off or on. Wish I had big wire buried to shed where tractor & gen are. Have to get out in weather but is wonderful to have power.

[MikeZ]

Sorry forgot to add
I talked him into throwing nice used disconnect . No worries about any jury rigging, because I can sure do that. Get transfer disc.

[ChopperDan]

Per Nec power needs to be switched from generator to line power with a single though of the handle.

I would use a breaker handle tie.
You can find it here. It's UL listed. If you had a fire your insurance wouldn't be able to give you a hard time over it.
http://www.interlockkit.com/

Dan

[Icehouse]

Per Nec power needs to be switched from generator to line power with a single though of the handle.

I would use a breaker handle tie.
You can find it here. It's UL listed. If you had a fire your insurance wouldn't be able to give you a hard time over it.
http://www.interlockkit.com/

Dan
[/quote
I have been a Electrical Contractor for many years. That interlock kit that you showed is one of the neatest things I've seen, gives options for many applications. It's kind of spendy but not really, allows for a clean fix. Folks must realize that, depending on generator size, they can't run all items under the main breaker but have to be selective. Great post thank you

[den]

Here is another option, but it isn't cheap.
It fits between your meter and meter base. Some light companies sell them.
http://www.generlink.com/about_generlink.cfm

[walterkilo]

Hi,

Without knowing the size of your generator, I would simply install a proper double pole breaker in your main Inside pannel and install a proper twist-lock outside to plug in your generator.  You will also need an outside grounding rod.

Your main breaker is enough to isolate your house from the main power source during a power outage.

Nothing automatic here ! Just a simple manual setup !

[scsmith42]

The two methods that meet code are either a manual transfer switch (MTS) or an automatic transfer switch (ATS).  Usually you can find a good deal on an MTS.

You can size them two ways.  First, based upon your service amperage (usually 200A, but sometimes 400A).  Second, presuming that you don't have a 200A backup generator you can swing only the circuits that you want to feed with the generator over to a subpanel, and use a smaller transfer switch for the subpanel.  This is how I have the ATS on the propane standby generator for my house wired.

Often times you can pic up a transfer switch on ebay for a few hundred bucks. 

[Jim_Rogers]

I have set up two transfer set ups with two generators. One was for my house back in 1999 as my wife was afraid of Y2K that the power would go out when the calendar changed from 1999 to 2000. We use it every winter for power outages.
I now have the generator in a "dog house" next to my outside plug.
When the power goes out and we find out from the power company that it's going to be hours and hours till it's fixed, I go outside and plug in the generator. Turn it on and go back in the house. When I open the cellar door the light I have plugged into the outlet on the transfer box is on. So I can see my way to the transfer switch box. I flip all the switches from "line" to "gen" and the house comes back to life.

The second set up I did was here at my mother's house. She's 94 and in a wheelchair. There would be no way for us to take her to a shelter if the power went down. So we set up the same type of set up here. I have the generator, on wheels, in her garage. I wheel it outside of her garage and plug it into an outside "generator" outlet. Then go to her basement and turn all the switches from "line" to "gen" and her place is up and running like normal.

Of course I have to do these switch changes at both places but we haven't had a problem with either of them, for many years.

The "electrical" guy at Home Depot where I got the transfer switch was a former electrician and he helped me to get all the right size items I needed to completely do it safely and correctly.
I ran a wire across the cellar to the outside outlet and got a very long heavy duty wire for hooking the generator to the house, so that the generator could be outside the garage on the opposite end of the house from my mother's bedroom to hopefully reduce the amount of noise it would make to keep her awake at night. Due to her being hard of hearing, I don't think she can even hear it when it does run.

Several years ago, we had the power go out when we had a bad ice storm in my home town area. Here at the sawmill yard nothing happened.
We had to run the generator for over 100 hours until the power company got all the lines fixed to get the power back on to my neighborhood. I think I ran something like 30 gallons of gas through that outage.

Jim Rogers

[ChopperDan]

I found the interlocks cheaper here

http://www.natramelec.com/