Anybody have whole house generator installation experience?

[SlugSlinger]

I purchased a 20kw and looking for estimates to install. Are there any electricians that would be interested! Or can someone provide referrals?

 

[Oklahomabassin]

Electrician Mike on here, might be able to help you out.

 

[mbalexander]

I'm a licensed electrician & plumber. I have installed some generators, gas line & all.

 

[SlugSlinger]

That's a long drive from Newcastle. I'm debating placement of the generator. I can place it within inches of the gas meter and there is a 1/2 stubbed out there. However my electric meter and box are on the opposite side of the house, probably a 100" run. I had a pool panel installed when we built the house and it is within 20' of the gas meter, but it is on a 70 breaker. My ats is a rxt 200 amp switch. Can the unused pool panel be used? What does your average install run?

 

[tyromeo55]

A good electrician is going to have to look at what you have to hone down what you are going to need to do the job right.



Is it a Generac generator?? I'm going to assume your on Natural Gas. I found a cut sheet for a Generac and it list a 20KW as 18KW of output using NG. It specs a 90A CB and needs almost 300K BTU of gas. If you no longer need the spa panel and it was properly wired for a 70A breaker then it might be possible that it could be used and the transfer switch mounted close to the meter. 1/2'' even right at the meter is no where big enough for that generator. I'd guess your going to need a 1"

 

[Okie4570]

Just make sure the installer places the exhaust pipe higher than the eaves of the house. We've run on a couple of houses that weren't, and exhaust was entering the house thru the sophet vents, filling the house with CO.

 

[murphy j]

PM sent

 

[SlugSlinger]

A good electrician is going to have to look at what you have to hone down what you are going to need to do the job right.



Is it a Generac generator?? I'm going to assume your on Natural Gas. I found a cut sheet for a Generac and it list a 20KW as 18KW of output using NG. It specs a 90A CB and needs almost 300K BTU of gas. If you no longer need the spa panel and it was properly wired for a 70A breaker then it might be possible that it could be used and the transfer switch mounted close to the meter. 1/2'' even right at the meter is no where big enough for that generator. I'd guess your going to need a 1"

Yes it is setup from the factory to run natural gas, but is very easily converted to lp with included hardware. I've considered burying a large propane tank to provide true emergency power in case we lose all utilities.

The regulator is mounted in the generator box and it is a 1/2" npt inlet. The specs do show a minimum of 1" pipe but with the inlet being 1/2", how does that work?

 

[tyromeo55]

Yes it is setup from the factory to run natural gas, but is very easily converted to lp with included hardware. I've considered burying a large propane tank to provide true emergency power in case we lose all utilities.

The regulator is mounted in the generator box and it is a 1/2" npt inlet. The specs do show a minimum of 1" pipe but with the inlet being 1/2", how does that work?

NG is delivered to the customer at a VERY low pressure like from just a couple ounces up to 1.5 Lb . The longer the distance from its source the quicker it looses its ability to move the gas. Also. Every time you add a fitting like a 90 deg elbow you're going to also further reduce.

Think of a short straw and a long one stuck into your favorite drink. Your going to get a lot more drink out of the short one then one of the same diameter but longer.

Here is a chart I found quickly. I dont have a code book in front of me so I dont know how it correlates to our code but it is good enough to get the idea.

http://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html

 

[David2012]

I've got a Generac 20KW with the auto switching box feeding the main fuse box 200 amp breaker... not just isolated circuits. It cost approx. $400 to have plumbers run a 1" gas flex line 30 feet underground from the main line by the meter to the generator and do the hook-up & pressure check. I also had a emergency cut-off valve installed so anyone could cut the gas supply off by simply turning the lever 1/4 turn were there ever to be a emergency.

As for the electrical wiring, I recommend that you put it as near to your meter / main box as you can.. as the price of copper wire will dig into your wallet. I couldn't give you a estimate of what the electrical hook-up of the generator costs as I had some other work done as well. But I can tell you that I had to bring my wiring from the weather head to the meter box...to the main inside breaker box up to current city code.. as it was wired with stranded aluminum wire. 130 feet of #2 stranded copper wire to do the main wiring cost me right at $700 at Locke's Supply back in mid-2010. Copper prices were so volatile that they were quoting prices every 24 hours. If you got a quote on the wire today.. it might be different tomorrow morning. That didn't count the cost of all the smaller wires it took to hook up the control & battery charger system.

If you haven't hooked your gas up yet, here is something you might want to consider. Instead of a 1/2" or 3/4" line coming off of one of my other house lines near the generator, I went with a independent 1" gas line coming off my main large house line by the meter so I would be sure of having enough gas pressure going to the generator during a major ice / cold event like we had several years ago. We were without power for 7 days. At the generator, there is a reducer necking the 1" line down to 3/4" I believe.

After talking with the plumbers about the required line pressure needed for the generator to work properly, we figured during a extreme cold event that the central heat unit, the gas hot water heater, the gas dryer and several axillary blue flame heaters in the house might cause a drop in gas pressure on any lines running from the house to the generator...so that the generator might not function up to full capacity. So instead, they taped the main gas line to the house just this side of my meter. The plumber felt that by coming off that large line and running a 1" flex line to the generator... that we would always have enough pressure going to the generator no mater how much we ran gas appliances inside the house.