New construction/Automatic Backup switch install Now or later.

[Hiball]

I currently in the middle of a New Home build and my electricians have been running wires for the last week. I had casually mentioned that at some point in time I might want to add backup generator and if there was anything I should do now that would ease the installation later. One of the suggestions was to go ahead and add a 100 amp Automatic transfer switch now, wired for the appropriate circuits that we picked out. I’m not for sure what ATS they are wanting to use, but I see Generac sells their own ATS with their generators. Are they all pretty much universal? My electric skills top out at wiring a 3 way switch, so it will be done by an electrician at the end of the day regardless.

Thanks in advance

 

[Zeke]

A lot easier if the framing is open and the main panel is flush. At least put in conduit stubs needed to get from A to B later. You can choose what type of transfer switch when the time comes.

 

[wyliesdiesels]

Easier when the walls are open

They are not universal.

Do you want to backup the entire house and use load shedding modules to shutoff the large loads that the gen cant handle or do you want a branch circuit transfer switch for only certain loads?

An ATS that covers the entires house allows more flexibility in that you could power any load the gen can handle. Whereas a branch circuit transer switch will only cover the circuits you pick ahead of time that get wired to it...

 

[nadogail]

Much easier and less expensive to install wiring during the framing stage of construction than later.

 

[35Ford]

It depends. Way too many variables. Permanant or portable generators are added after the fact all the time without much trouble. Talk to your electrician. He should be able to advise you.

 

[Hiball]

Easier when the walls are open

They are not universal.

Do you want to backup the entire house and use load shedding modules to shutoff the large loads that the gen cant handle or do you want a branch circuit transfer switch for only certain loads?

An ATS that covers the entires house allows more flexibility in that you could power any load the gen can handle. Whereas a branch circuit transer switch will only cover the circuits you pick ahead of time that get wired to it...

I ended up with 2 electrical panels in the garage, the circuits that have been designated to be run off the generator have conveniently been designated to the sub panel for ease of wiring the 100 amp ATS. The LP and planned standby generator location is opposite the wall, give or take 5’. Since my electrician doesn’t do the generator install and would only be wiring the ATS I really just needed to know if they were universal across Generac, Kohler, and champion because I haven’t picked a brand.

I guess if I don’t decide prior to drywall/siding installers there will need to be some demo/siding repair as the panels are currently mounted in a 2x6 wall cavity.

Thanks again.

 

[cherokee]

We had ours installed about 10 years after we moved in, then it replaced about 10 years after that when the engine started using a bit of oil.

I think it is really going to depend on just where you main panel is. If it is on an outer wall that is at ground level I highly doubt it will be much of an issue, ours was not.

The rest of it I don't think you could do now. Like @wyliesdiesels said they are not all the same, and depending on how long it is before you have it installed what you put in now could be money wasted. I know our old transfer switch had to be replaced with the new gen and it was the same company.

As to the what it will run, some of it is a no brainer, freezers, fridge, if you have gas heat, the furnace and blower motor. If you are all electric get ready to spend quite a bit more for that, as well as with the larger gen you are going to use more fuel, more kw the bigger everything is. And this might change as you get into the house. We had the freezers in the basement and moved them to the garage, different circuit now.

My suggestion is have penetration from where you plan to put the gen and a way to get to the panel, usually they put their "sub panel" right there with the other one, just makes hooking everything up more easy.

There is also a manual transfer panel. I just did this in my shop as part of the solar setup. Fairly easy and I bet if you can do a three way switch you can handle this. You manually switch between the "main" and "gen" power, and what you want on what. I really like this feature. The one I bought has a crude little meter saying what is going where. I have another more accurate digital meter that is what I look at.

 

[dcg9381]

I’m not for sure what ATS they are wanting to use, but I see Generac sells their own ATS with their generators. Are they all pretty much universal? My electric skills top out at wiring a 3 way switch, so it will be done by an electrician at the end of the day regardless.

I can't wire a 3-way switch without a book. I have wired ATS and installed interlocks.

It's going to be a lot easier now (and less expensive) to put in an ATS. As I understand it, most generators can be adapted to Generac's ATS but they are not universal. Generac owns most of the consumer market anyway - and you're very likely to end up with their product.

Decide if you want a "partial" ATS - like the 100A that you mentioned where you need to define what circuits are protected. That's going to be something you want to now even more than installing a 200A ATS that does everything as it's more complicated to retrofit later. Frankly, it may be less expensive to do a 200A ATS and 20KW generator than doing the extra work to separate out circuits.

Around here it's $7k-$9k to install a 200A ATS after the fact. Doubles (or more) the cost of a generator install.

Generac also has "load shed" devices that are not that expensive. Alternatively to selecting primary circuits to protect, you could put those in now. These are "product independent" - they're basically normally open big switches that are on timers and open the circuit when voltage or frequency goes out of standard. They're not real expensive. Easy to install. You can get them in 100A variety.

IMHO, when you get around to getting a generator, not a huge difference between a 10K and 20K generator in terms of price after all this work.

 

[Hiball]

Appreciate the comments, Since my electrician doesn’t do the generator install itself, I called a company that does this Am.
I’m going to have a conversation with him today to make sure a 100amp ATS is sufficient. My house will have a ground source heat pump, including a 10k electric backup for extended cold spells. I don’t have the specs in front of me currently, but the generator installer seemed very hesitate with the 100 ATS.

 

[dcg9381]

Appreciate the comments, Since my electrician doesn’t do the generator install itself, I called a company that does this Am.
I’m going to have a conversation with him today to make sure a 100amp ATS is sufficient. My house will have a ground source heat pump, including a 10k electric backup for extended cold spells. I don’t have the specs in front of me currently, but the generator installer seemed very hesitate with the 100 ATS.

With a 10k draw possible single draw, you're going to want a 20k generator.
I think you best bet is having your electrician put in the ATS now. The generator guys are going to bend you over on the ATS install. I'd choose a 200A ATS, but doing a 100A ATS with split circuits is OK too.

 

[RPH]

Do it for all the reasons outlined. Easier and cheaper plus electrician does the hook up. Inspection done too!

 

[dcg9381]

OP, want to mention that with an ATS properly installed it's not a big deal to add the generator. If you can do 3-way switches, you are GJ "qualified". It's 3 power wires and a set of color coded control wires. At least with a Generac.

Now getting a 20K generator landed in the right spot, that took me and 4 neighbors....

 

[wyliesdiesels]

OP, want to mention that with an ATS properly installed it's not a big deal to add the generator. If you can do 3-way switches, you are GJ "qualified". It's 3 power wires and a set of color coded control wires. At least with a Generac.

Now getting a 20K generator landed in the right spot, that took me and 4 neighbors....

it should be 4 wires- 2 ungrounded conductors (2 hots), 1 grounded conductor (neutral), 1 grounding conductor (EGC/ground)

 

[dcg9381]

it should be 4 wires- 2 ungrounded conductors (2 hots), 1 grounded conductor (neutral), 1 grounding conductor (EGC/ground)

Thanks..