# Backup Generator



## Gordon H. (Aug 3, 2018)

I'm thinking of installing a backup generator. Got an estimate over the phone from one guy who told me the whole package, including install would start around $15K, well after I recovered from the shock, I'm thinking about doing most of the work myself (the gas portion I will leave to a plumber) but I can run the conduit and wires from the utility room to the generator (about 75') myself and save some bucks.
The unit I'm looking at is a Generac 11kw LNG unit with a 200A whole house auto transfer switch. The two legs, neutral and ground wires (I figure 6AWG THHN because the unit has a 50A breaker) and the five signal wires (18AWG) should be able to run in 1" Sched. 40 PVC conduit (my calculator puts it at a 27% fill rate).
Does anyone know if I can run the gas piping and the elec. conduit in the same trench?.
I'm also concerned about the 90 degree conduit bends - do I have to use those 90 degree PVC elbows with the large radius bends or can I use one of those conduit bodies (or even something else)? - there's a couple of bends in my basement ceiling that may need to be tighter than the standard elbows.
Thanks!


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## cda (Aug 3, 2018)

Welcome 

How is Don T.?


Anyway 

Have you talked to your city Building dept about what you want to do 
And what you need??


I take it you have done electrical work before??

You could also shop around and see what prices you get. Hd and lowes I think have installers. 

Give it a day or two for answers to your other questions


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## Msradell (Aug 3, 2018)

You didn't state what part of the country you are in but I think you different need to shop around a little bit.  We installed a 20 KW natural gas Generac fully installed including transfer switch for little under 10k a couple of years ago.  The generator is right next to our gas meter so the gas piping was very easy but the logical output is about 75' to the transfer switch and panel.  If installed by a Generac certified electrical contractor not some fly-by-night installer from one of the big box stores.


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## Gordon H. (Aug 3, 2018)

I haven't talked to the town yet, I'm still in the preliminary stage. I do have another contractor coming on Tuesday to give me a quote however, one thing I'm beginning to realize is that many of these installers wind up subbing a lot of the work. A true one-stop installer would need to be a mechanical guy to do the trenching and foundation/base for the unit, a licensed electrician and a licensed plumber. I've checked out the licenses of a lot of the 'generator installers', most of them only hold an electrical license which means the have to call in someone to do the mechanical and plumbing work. I have a friend who owns a company who can do the foundation (I'd like to put up a cinder block base about 18" off the ground to keep the unit out of the snow) and the trenching work. I also have a service contract with an HVAC contractor that is licensed to do the gas piping...why not GC the job myself?
I'm a mechanical engineer and work as an estimator in the airport (jet bridges and baggage conveyor systems) industry. I'm comfortable with coordinating various subs to accomplish projects. I'm also comfortable doing electrical work and through my company, I can probably get a better price on the wires than most electricians (we buy a lot of large cable direct from the manufacturer). I would feel very comfortable running the wires/conduit  from the utility room out to the generator and hiring an electrician to do the transfer switch install. Some of the things I'm unsure of has to do mainly with the outdoor work i.e. can I run the gas and electric in the same trench?, Is there a requirement for the depth of the trench etc.


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## Gordon H. (Aug 3, 2018)

Msradell said:


> You didn't state what part of the country you are in but I think you different need to shop around a little bit.  We installed a 20 KW natural gas Generac fully installed including transfer switch for little under 10k a couple of years ago.  The generator is right next to our gas meter so the gas piping was very easy but the logical output is about 75' to the transfer switch and panel.  If installed by a Generac certified electrical contractor not some fly-by-night installer from one of the big box stores.



Thanks for that info, I'm in NY on Long Island. The proposed site would be about 15' from the gas meter. The panel would be about 75' from the unit.


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## cda (Aug 3, 2018)

Gordon H. said:


> Thanks for that info, I'm in NY on Long Island. The proposed site would be about 15' from the gas meter. The panel would be about 75' from the unit.



Oh the boca raton is your winter stay?


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## cda (Aug 3, 2018)

You should also talk to the electric utility company about what they require


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## Gordon H. (Aug 4, 2018)

cda said:


> Oh the boca raton is your winter stay?



Boca is my Sister in Law's winter stay (I'm not that so fortunate)


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## north star (Aug 4, 2018)

*@ ~ @*

Regarding the separation of the gas supply line and the electrical
wiring assemblies in a trench, we have had this very discussion before.

*https://www.thebuildingcodeforum.com/forum/threads/lp-and-electrical-conduit-common-trench.11092/page-2*

While the utility companies [ typically ] place these two energy
systems in the same trench, the local Code Official may have a
different viewpoint on the matter........There is nothing in the
International Fuel Gas Code or the NEC that will prohibit both
from being in the same trench, however, there are some minimum
"fill coverages" required for both......The gas line has minimum of
12" of coverage required.......If plastic pipe is used, then a copper
Tracer wire is required to be installed.

Some have said that a minimum of 12" horizontal distance between
the two is required, but I do not have a Code to cite in support of
that.

Here's what I recommend, ...contact the local Code Official to see
what is actually required......In the future, if repairs had to be
performed on one or both of these two different systems, would you
prefer working closely to each system, or would you prefer to have
at least 12" of horizontal separation ?.......The point is, doing more
than the minimum is still acceptable, and IMO, ...more separation
would provide me a greater sense of comfort on my investment.

Also, I believe that there is a minimum 3 ft. separation distance
away from the residence of the genny itself [  i.e. - fire rating of
the Generac housing  ?  ].

*@ ~ @*


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