? connecting 120V 30A generator to the house panel...

I've watched many videos on this.

This is what I understand- school me if any of it's wrong.

The 'grid' supplies the electrical panel side A and B.

A double breaker is used for 240 b/c it takes power from both sides of the panel, or 2 x 120V

Many people just run a wire from the Genny to a 240 receptcle and shut off the main/grid power.
I would do this too, but I don't want a LONG cord running in a door or window- especially in the winter.

(Yes, I know there are laws about this, permits, etc.)
This would power both sides of the breaker panel sides A and B.
(yes, I know it won't run any 240v items- I don't have any, gas range, gas clothes dryer.) Rarely use the A/C.

When hooking up the 3 prong receptacle for the 120V genny to go to the panel in the house, it will go thru a receptable box outside with wires into the house. I have looked in the panel at the wires going to the dryer- there are only 3 wires. A copper bare wire, and one black and one white.
There will be one ground wire, and one wire to each of the 2 skdes of the double breaker, a white and black.

House is near Milwaukee, built to code in 1990.

There are no empty slots left in the breaker panel to put a Generator interlock device on it to keep the now incoming breakers from the generaotr on or off if the grid power is on. That's a whole 'nuther thread.

I'm not an idiot and would always turn off the main breaker- I wouldn't want to start giving other people, or the line power in a power out.

What did I miss?

 

Basically correct, but HIGHLY ILLEGAL. Do not connect a generator to the grid without a true physical disconnect.
A breaker is not good enough, they can fail and pass current even when you think they are off. Do it right , or don't do it.

 

OK, but the purpose of the little plate thingy is to keep the main breaker off when the Generator fed breaker is on?

 

I'm not certain of what "little plate thingy" you are referring to, but yes some have a "safety lock out" to prevent someone
from easily flipping a main breaker on while someone else happens to be working on down stream wires.
People may use it as a method of separating the house from the street, but it is not a guarantee.

I know that breakers can fail this way because it happened at my Mom's house. It was a big surprise to
find the main breaker left the lights on when it was switched off. House was about 35 years old and my parents built it it 1970.
We ended up replacing the entire panel and adding an automatic transfer switch when we went to install a Generac backup system.

By your description it seems like you will need a new main panel to do it right, as well as a transfer switch; either manual or automatic.

 

https://www.generlink.com/ Some utilities will give/subsidize one of these.

 

Plates are legal and easy way to do it. I did this on my house.
No empty spots should not be problem, just double some breakers to make rook for generator breaker.

 

What he is referring too is "generator interlock" basically when you mount your generator breaker next to main power supply, plate is allowing only one breaker to be ON while the other one MUST be OFF. Did this to my house with my diesel generator and worked like charm!

 

He is saying breaker itself can fail and let current go through. I guess you could say same for automatic switch, they can fail as well.
If I was using big generator dedicated for house only I would have used automatic switch. With portable generator I just roll it there if needed and switch manually.

 

Thank you for confirmikng. I did some research.

I didn't think of combining a few breakers - it would be easy actually as most all lights are LEDs, etc.
My 1990 breaker panel is so old though, I'm having trouble finding a Generator interlock plate for my panel. I'm pretty sure I can still make it work though. It's not rocket science. No one in my family will be messing with this- except me.
Power goes out for than say, one hour:
You flip ALL breakers off. Especially the main- as this would put your genny power back to the grid, and under power some homes near you, and/or injure a lineman- who are Ultra protcted anyways.
You power up your generator
you flip the generator breaker on, and start adding breakers so that my fridges, lights, and my large reef tanks are all powered up again.

Win win!

I'll probably move breakers around, and double one or 2 to have an interlock plate on it, and get a permit for it.

Thanks all for the replies!!

 

Here is a picture of the little "plate thingy", also known as a generator interlock. The input from the generator is the two pole breaker on the upper right side. As long as the panel main is turned to the on position, the generator breaker cannot be turned on. Once the main is off, the the metal plate can be slid upwards and the generator input breaker can be turned on. So when the plate it up, you cannot turn the main on again until the generator breaker is turned back off. That is an older picture as the generator breakers are a double pole 30A. I now have a 12,000W generator and as such, the inlet breakers were changed out to a double pole 50A.
These are perfectly legal as per the NEC. there is nothing automatic about doing it like this. If I lose power to the house from the utility, I have to go out to the garage and start my 12,000W generator, and while it's warming up a bit, I turn off all the breaker that I don't want on. Then I turn off the main 200A breaker and plug the generator into the generator inlet (NEMA 14-50) receptacle, and hook up the cord, then turn the two pole 50A breaker on.



I've also added a set of very specific instructions for getting powered up, as well as returning back to Utility power once my alarm goes off that utility power has been restored. I have an audible alarm (105 db siren), a visual alarm (red LED light), as well as an indication on my home burglar alarm system that tells me that utility power is back on..


Here's what it looks like under the breaker panel. A "PowerBack" module, the generator inlet, hanger for the cord, and a box I built to contain a relay that turns on the red light in the garage for utility power restored, and a set of contact that closes as a signal to an alarm module that tell my burglar alarm that power is back on.

 

The interlock setup is what I have in my house. Totally legal, no issues. Have used it a few times over the years. Generator runs in a large barn style shed and the power cord plugs into an outdoor rated outlet that feeds the main panel.

 

Did you look here https://interlockkit.com/shop/ pages and pages of plates.

 

Yeah, Naw, not paying $149 for piece of metal. Others are less than $50.

Thanks everyone.

I plan to do this soon, and NOT get hurt/die. LOL

 

I used site just to find out which plate fits my box. It was $42 on amazon

 

I think I found one that looks like my panel. By moving a few breakers around, this one should work!

https://www.ebay.com/itm/2747373677...MIkZCG2dqUhAMVOQutBh2K6QesEAQYAyABEgKrcPD_BwE

 

That sounds a lot more reasonable. IIRC, mine was somewhere in the $40 range, but that's been 5 or so years ago.

 

Theoretical question: what happens in the event that Dumb Homeowner backfeeds into the house but does not shut off the main? Unless the break is the line directly to the house, I assume the generator will instantly trip as it tries to power the neighborhood.

 

That's why the only two approved methods by the NEC is the mechanical generator interlock, like I posted the pictures of, above, or using a transfer switch....either manual or automatic.

And if using a generator setup like mine, generator interlock, the generator needs to have the neutral/ground bonding in the generator removed, as I have done on mine.

 

Tell be more about this nuetral/ground bonding? I"m using the 120V 30A 3 prong circular RV plug in on my Generac 3600 Genny.

 

Within the breaker panel on your house, the neutral buss and the ground buss are bonded together, which simply means that they are connected together electrically, as is required by the NEC. It is also against code to have 2 different neutral/ground bondings, and that is where you will have to check on your particular generator. So here is the scenarios, as far as generators go. A portable generator will either be a neutral bonded, or a floating neutral, or one like mine that you can change it to whichever scenario that you need. Mine came as a neutral bonded, but has a jumper that can be removed to make it a floating neutral, which is what you need it to be if you are using a mechanical generator interlock like I pictured above, and wiring the generator to provide temporary power to your house. I'm going to post a link to a site that tells you about that and what is needed. It is possible to use a neutral bonded generator for supplying temporary power to your house, BUT, Not while using the breaker interlock method for isolation. It will require that you buy a switching neutral transfer panel and have that installed. The link will go into more detail....

Scroll down the page after it loads and pay attention to the answers that are under this...."You can't use an interlock with a bonded neutral generator"

https://diy.stackexchange.com/quest...ng-to-house-and-removing-bond-in-main-panel-i