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Huntn

macrumors Core
May 5, 2008
23,589
26,706
The Misty Mountains
I have an external outlet box near where I run the generator. And on my main panel, I have a generator interlock switch. I have a 30 amp setup, but ran wire able to handle 50 (I just have to change the panel breaker, and the outlet in the box to match).

For anyone who isn't aware, a generator interlock switch is a plate that is mounted to your panel box cover that prevents you from turning on the generator's breaker (to back feed the panel) without shutting of the main breaker (to prevent you from back feeding the grid which can kill people). They are panel specific, so you have to order the correct one, or design one for yourself. I mounted mine while my electrician ran the wire and outlet. I toughly tested to make sure that there was no way the generator's breaker could be on at the same time as the main, if you flip the generator's breaker it throws the main off, and the same goes for not being flip the main on without it shutting off the generator's breaker.

The beauty of this is you have the ability to select which circuits you want to power. For example, during the winter I want to power my heating system, in the summer I want to power the master bedroom's ac.

Luckily all my wall unit ac's are on their own circuits, so I flip them off to prevent anyone from using them (including my 220V 1st floor unit).

I do have to watch my neighbors to see when they get power back on, the last time, I was on my generator for at least an hour after the power came back on. The good thing is now my utility company as real time app notifications. So, when it comes back on, the meter lets them know, which sends a notification to the app.
My setup is that only the circuits I move to the generator are disconnected from the street power, so it would be easy to leave a light on for a house circuit, for a signal for when street power comes back online.
 

elvisimprsntr

macrumors 65816
Jul 17, 2013
1,031
1,534
Florida
I have an external outlet box near where I run the generator. And on my main panel, I have a generator interlock switch. I have a 30 amp setup, but ran wire able to handle 50 (I just have to change the panel breaker, and the outlet in the box to match).

For anyone who isn't aware, a generator interlock switch is a plate that is mounted to your panel box cover that prevents you from turning on the generator's breaker (to back feed the panel) without shutting of the main breaker (to prevent you from back feeding the grid which can kill people). They are panel specific, so you have to order the correct one, or design one for yourself. I mounted mine while my electrician ran the wire and outlet. I toughly tested to make sure that there was no way the generator's breaker could be on at the same time as the main, if you flip the generator's breaker it throws the main off, and the same goes for not being flip the main on without it shutting off the generator's breaker.

The beauty of this is you have the ability to select which circuits you want to power. For example, during the winter I want to power my heating system, in the summer I want to power the master bedroom's ac.

Luckily all my wall unit ac's are on their own circuits, so I flip them off to prevent anyone from using them (including my 220V 1st floor unit).

I do have to watch my neighbors to see when they get power back on, the last time, I was on my generator for at least an hour after the power came back on. The good thing is now my utility company as real time app notifications. So, when it comes back on, the meter lets them know, which sends a notification to the app.

I did the same. I was on critical infrastructure until they installed a permanent industrial CNG Kohler at the waste water pumping station.

While I’m not a licensed electrician, I had to float the neutral on the generator to comply with US NEC to prevent two neutral bond points (panel and generator) and put warning labels on the generator that it is no longer configured for stand alone use.

b5cbf9ce084714bcbbed0c9e3a63b51b.jpg
 
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max2

macrumors 603
May 31, 2015
6,409
2,036
Does anyone know much about them here?

Not how to install but price range in general.
 

Herdfan

macrumors 65816
Apr 11, 2011
1,136
7,648
Price is going to depend on multiple factors such as proximity to a gas source and the meter base so it hard to ballpark without knowing this.

When I had my generator put it in my old house, I had to run 100'+ of gas line, but the generator was close to the meter. At my parents, the generator ended up right beside the gas supply, but had to run 75'+ of wire to get to the meter.

At my current house, they are literally side by side so less than 10' of each.

And then there is the "how big do I need"?

Here is an example, when the Derecho blew through from Chicago to DC back in 2012, almost everyone in my area lost power. I had a small 5500 generator, but it was not enough to run the house in 95 degree/high humidity weather.

So while everyone else was at HD getting on the list for portables, I went straight back and got a big one: 17kW. It came with the 16 Circuit ATS. So I had to pick which 16 circuits I wanted to be on the generator. And some, like A/C, ovens, dryers, etc count as two. But we made it work for a couple of years. But it wasn't enough to fully run my house.
When when my dad had to go into assisted living, mom decided she wanted a whole-home generator, so we made a deal. She got my old one for what I paid ($4,400) and she would pay to have it installed at her house.

I then had them install a 30kW at my house. I paid around $16K for that, but they didn't have to run the gas line since I had already done that. I got the 30k@ and 2x200W transfer switches.

The big difference between the two was the 17kW that went to my mom's house was air-cooled and mine was liquid-cooled. Air-cooled generators are generally smaller and louder than liquid-cooled.

Mom paid like $4,000 to run the longer electric line and buy an ATS plus what she paid me for the generator.

My advice is get several quotes. The "generator" companies are most likely going to have the best price as they have a repeatable model vs a regular electrician who is able to install them as he may have to hire a plumber for the gas work where the generator company will have a licensed plumber on staff.
 
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icanhazmac

Contributor
Apr 11, 2018
2,584
9,843
My only advice, given your lack of details, would be to buy a name brand that has some backing. This is not the time to save a few bucks at Harbor Freight (not bashing HF as I have lots of their stuff). I own a Honda genny.
 

steve123

macrumors 65816
Aug 26, 2007
1,019
595
You can use a smaller generator for a residential application if you include a Tesla Powerwall battery. A properly sized Powerwall will provide the reserve capacity to meet your peak demand. You can add some solar as well if you want.
 
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