Install my own generator?

[skamp]

Probably a dumb question about conduit size, but… For the install of my new Generac stand by generator, I’ll be running 4/0-4/0-4/0-2/0 (aluminum) and 6 x 18ga from the generator to the transfer switch panel.

I don’t intend to ‘pull’ the wire through the conduit, rather I’ll thread all the conductors though the various conduit components loose and glue it together as I go along. According to the Southwire conduit fill calculator, 1 ½” conduit is not up to NEC code (at 54% filled). I’d prefer to stick with 1 ½” because the knockout in the generator cabinet is that size. Will I be creating a potential problem later on by going with the smaller conduit, or should I just stop being cheap and lazy and upsize to 2”?

For your reference, all total, from the generator to the transfer switch panel will be under 16’

If it’s only 16’ why not use 2/0 copper. It’s more expensive but it’s a short run.

Steve

 

[imagineer]

Just going off what my plant electrical tech said I'd need for 200amp service. Also, I believe 4/0 aluminum is what is run from the meter to my circuit breaker panel.

 

[mm08822]

You only need 1-1/4” conduit to run 3 #1 XHHW AL and 1 #6 XHHW AL (green) between the gen and xfer switch. At 24 KW derated for NG output, the maximum continuous current is 87.5 Amp. 87.5a x 115% = 100a. #1 XHHW AL good for 100A.

The generator has knockouts for 1-1/4” and ¾” conduit. Use ¾” conduit for the control circuit and pull #14 thhn/thhw.
Use sealtite to connect at the gen, don’t hard pipe it.

Don’t pull any wire until conduits are completed.

The only place you need 4/0 Al is between meter to xfer switch and then from xfer switch to the former main panel.

The former main panel now becomes a sub-panel and needs a 4-wire feed out of the xfer switch.
Neutrals need to be isolated from ground. Add grounding blocks and re-land all grounds on this.
Make sure to pull out any bonding screws or straps.

Move the grounding electrode conductor and water pipe bonding conductors to the xfer switch. This is the new main panel.

Depending upon positioning of equipment, it can sometimes be easiest to run 2” conduit from xfer switch to former main panel.
Use 2 - 4/0, 1 - 2/0 and 1 #4 XHHW Al. You don’t need copper. Otherwise, 4/0,4/0,4/0,2/0 SER.

With xfer switch outside next to meter, use 2” ****** between it and meter pan.

All that is needed is to shut off the main cb and then pull the meter. Then all connections from load side of meter are dead to work on. No need to bother POCO. (Not for you to do.)

PICS of the intended gen pad, electric meter area, main panel and gas meter would help to narrow down the details.

Plan on needing a gas meter size upgrade. For this, you will need all existing gas loads and the new gen load.

 

[AA/FC]

If they turned off the NG were I live during the winter months thousands (millions maybe?) of people would freeze to death.

They don't turn the NG off here where I live..... Not on purpose anyway.

 

[mike93lx]

I am pretty sure that technique is not to the NEC - which requires wires pulled through completed conduit. Your way you will get glue on the wires and may even glue them to the conduit.

Don’t take me as the last word - hopefully one of the practicing electricians will confirm or deny...

It is absolutely a code violation and a bad idea. The pvc cement will damage the wire insulation.

 

[Sumboodie]

If a gen-set is not wired into a system correctly, there is a real possibility the gen-set could feed back into the shared power grid. There is the possibility of causing damage to other person's property and appliances. This is not the time to economize. Maybe you cam get one of the electricians move his schedule up if you offer $$$ome incentive.

That's basically impossible with a small gen set. It would stall or trip it's breaker before that could happen. Far too much load.

 

[Sumboodie]

In most installs the hardest part for a novice is the meter needs to be pulled in order to disconnect the line from the street ... In some areas the power company will actually do this for you.

You will have to lay out the install and see what works best. My nephew was lucky with everything in the same area -- both gas and electric service entrance and his AC compressors. The transfer switch was able to be attached to the meter pan with conduit and the rewire was easy.

What's the issue with pulling out a meter?

 

[mike93lx]

What's the issue with pulling out a meter?

It leaves unfused conductors accessible, reconnecting can arc, and it's illegal some places. Most meter cans have tamper tags on them and finding a cut tag can get your power shut off. At my last place, only the POCO could pull a meter

 

[yeldogt]

What's the issue with pulling out a meter?

I'm a wimp .... I just don't want to play with it.

 

[metschers]

I recently took advantage of a sale and purchased a 24kw Generac standby generator. My plan is to have it installed and run on natural gas.

My plan however is sort of up in the air as I can’t find a Generac certified installer who will install it because they are not the seller of the unit. There is one that will install it for me, but they’re 10-12 months out on their schedule.

I’m not an electrician, but I can follow instructions. Can anyone comment if this type of install should NOT be attempted by the homeowner? FWIW, there are plenty of plumbers around that I will be farming out the gas line.

I recently took advantage of a sale and purchased a 24kw Generac standby generator. My plan is to have it installed and run on natural gas.

My plan however is sort of up in the air as I can’t find a Generac certified installer who will install it because they are not the seller of the unit. There is one that will install it for me, but they’re 10-12 months out on their schedule.

I’m not an electrician, but I can follow instructions. Can anyone comment if this type of install should NOT be attempted by the homeowner? FWIW, there are plenty of plumbers around that I will be farming out the gas line.

Check out zillerelectric.com and zillerstore.com. There’s a lot of great information on generator installation and actual certified installers. There may be one in your area. I’ve installed three 22kw generacs. Ziller sells a really cool color coded wiring harness that connects the Generac generator to the Generac transfer switch. It made the installation much easier.
Hope that helps you in your installation.

p.s.
I don’t work for or am affiliated with Ziller, they’re a great source for information.

 

[imagineer]

My hat is off for those that make a living running heavy gauge power conductors. Good grief was it a lot of work getting the wires (4/0-4/0-4/0-2/0 plus 6 x 18ga) in 2” conduit from the generator to the transfer switch . . . it took me all day Sunday, and it’s still not connected at either end.

Like mentioned earlier, I didn’t “pull” any wire, rather threaded the conduit components over the conductors and glued it together as I went along.

Next on the agenda is to check the continuity on the 18ga wires to make sure they didn’t break during the install. If any did break, I’m going to abandon them and run new wires in a separate conduit.

 

[mike93lx]

Like mentioned earlier, I didn’t “pull” any wire, rather threaded the conduit components over the conductors and glued it together as I went along.

Like was mentioned earlier, that was a clear code violation and it almost certainly damaged the wire. Pvc glue will eat wire insulation.

Hope it doesn't cause you a problem. I would recommend never doing that again

 

[wyliesdiesels]

My hat is off for those that make a living running heavy gauge power conductors. Good grief was it a lot of work getting the wires (4/0-4/0-4/0-2/0 plus 6 x 18ga) in 2” conduit from the generator to the transfer switch . . . it took me all day Sunday, and it’s still not connected at either end.

Like mentioned earlier, I didn’t “pull” any wire, rather threaded the conduit components over the conductors and glued it together as I went along.

Next on the agenda is to check the continuity on the 18ga wires to make sure they didn’t break during the install. If any did break, I’m going to abandon them and run new wires in a separate conduit.

totally wrong, against code, and you may have issues. the glue is a PVC solvent which will eat the jacket on the wire

 

[wyliesdiesels]

What's the issue with pulling out a meter?

big no no here. when the PoCo finds out (and they do since its a smart meter) they send a tech out to see whats going on. they often fine people for doing so....

 

[imagineer]

Quick question regarding adding a ground bar.

Because the generator transfer switch will be the new primary disconnect, I'm required to separate the ground and neutral inside my existing electrical panel. To do this, I need to add a ground bar inside the existing electrical panel.

Whereas there are spots built into the existing panel for adding ground bars (with dimples and threaded holes), none of these are where I can easily access them. Is it ok to install a new ground bar (in a clear spot) to the back wall of the electrical cabinet using sheet metal screws?

The copper conductor on the left side is the ground to be disconnected from the neutral and I'm hoping to install a ground bar in that general spot.

 

[mike93lx]

You don't need to add a ground bar. You just need to isolate the neutral bar from the case and grounds

 

[imagineer]

You don't need to add a ground bar. You just need to isolate the neutral bar from the case and grounds

But the new wires from the transfer switch to the existing electrical panel has 4 conductors.
Don't I need something to attach that new ground to?

 

[mike93lx]

But the new wires from the transfer switch to the existing electrical panel has 4 conductors.
Don't I need something to attach that new ground to?

Yes, the ground bar. You only need another bar if you are out of space, but you can double up grounds to make room (not the same for neutrals...they are one per hole)

Adding a new ground bar only gives you more spots. The important thing is that the neutral is isolated. You absolutely have to ensure that

 

[theoldwizard1]

I cannot tell for sure, but it appears that the left and right "bars" are bonded by a single black wire near the top. If I am correct, removing that bond and then moving all grounds and neutral to the correct side (neutrals can be spliced to make the wire longer) and you would be all set.

 

[wyliesdiesels]

You don't need to add a ground bar. You just need to isolate the neutral bar from the case and grounds

he does if both existing bars are neutral bars which it appears they are

OP you also need to move any water/gas line bond wires and ground rod wires (GEC) to the transfer switch. I see 1 solid #6 entering this panel. this needs to be moved to the TS

 

[reader2580]

One note about NG. In a lot of areas, in case of emergency, flood, tornado, etc. one of the first things they do is turn off the Natural Gas. They do this because there are a lot of open pipes from houses gone. I looked into my area and decided on a 500 gallon (400 usable) propane setup so I would know I have gas available. This is just for your information. I did the total install on mine with a transfer switch, concrete pads for generator, and tank. I decided on what circuits I wanted on backup and what I did not need and wired only those circuits on backup. For instance I did not hookup an Electric stove as it draws as much as the generator can supply by itself.

My thinking on my whole house generator is if natural gas service is lost there are far bigger issues than having an electric supply for my house. A major storm took out power for three days at my previous house and I never lost natural gas for my whole house generator. I also have a 12.5KW diesel generator in my motorhome I could use. That generator would run 24x7 for about a week and a half on the fuel in the tank of the motorhome. I would have to convert the motorhome back over to 240 volt, but that is pretty easy.

 

[imagineer]

"the left and right "bars" are bonded by a single black wire near the top"
Yes, the two sides are bonded, and I intend to leave it that way. The plan now is to install a new ground bar near the top left side of the panel box. With the house de-energized, I'll pull all the grounds of the the two existing bars and route them toward the top of the panel and over to the new ground bar. All but a few wires should be long enough.

"I see 1 solid #6 entering this panel. this needs to be moved to the TS"
That is on the to-do list for the day the house is de-energized. There's a convenient spot inside the transfer switch for the ground.

Now my next question...
While nowhere close to complete, my generator install project is looking better. I have a plumber lined up to do the gas line. Given where the gas meter and generator are located, the plumber said it would be an hour long job, tops. The problem is he won’t have that hour until early September.

The question…Is it a bad idea to get all the electrical work done before the gas line is installed? I’d hate to just sit around for the next 3-4 weeks and not get anything else on the project completed.

In the next week or so, I plan to have the house de-energized for the task of isolating/moving the grounds (not keen about moving 30+ pieces of bare copper in an electrified panel). I figure that will take me 2-3 hours to accomplish; and another hour or 2 to run the new service entry cable from the meter to the transfer switch and finish connecting the conductors from the transfer switch to the main panel.

To accomplish this, I’ll take a day off and schedule AEP to pull the meter early in the day and (if all goes to plan) the job will be done by the afternoon for AEP to come back and plug the meter back in.

Also, for those of you concerned about my conduit faux pas, it's all good now. Actually, it all went bad, but it's good now. Despite the Generac instructions stating the transfer panel can handle 4/0 wire, turns out the generator can only handle 2/0. So the weekend worth of frustration, sweat and most of $200 spent on 4/0 wire was all for nothing.

After pulling the 4/0 wire out and re-doing parts of the conduit, I ordered an engineered cable from Zillerelectric.com and this weekend will be pulling it though and connecting it.

 

[White Shadow]

They Never turn off the NG here in Houston Texas..Fire, Flood, Hurricains and of course Sub Zero temps...

Same here. We had a rare tornado in South Jersey last September. A house 700 feet from mine was completely wiped out, but my generator ran on it's natural gas for two days straight.

I don't ever remember gas being turned off when I lived in NY either.

 

[imagineer]

Just to put some closure on this . . . the generator is installed and working perfectly.

 

[nadogail]

Thanks for the update.