~Standby generator wiring questions~

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  #1  
Old 06-20-19, 02:18 PM
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~Standby generator wiring questions~

I have been looking for an answer to these questions everywhere, so far no luck.
I ordered a Generac XT8000EFI generator https://www.costco.com/Generac-XT800...100408954.html, and want to use it as a standby for outages. I have seen people use a large RV extension cord to a RV type plug that's wired to and near their electrical panel. What I want to do is bury an appropriate' legally correct' underground wire about 200 ft away from my panel to a more permanent and secure, well ventilated building.
The questions are;
1.What gages wire would I need?
2. Are the cords three or four wire?
Thanks so much
 
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Old 06-20-19, 02:50 PM
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I have seen people use a large RV extension cord to a RV type plug that's wired to and near their electrical panel
That is not a standby generator setup. Standby generator is the one that will automatically kink-in when it detects power outage.

While it is possible to covert a potable generator to standby generator, it is usually easier and cheaper to go with ready made standby generator unless you already have a generator.

That generator has 30A 120/240V twist lock outlet and this is what most people use to hook up a portable generator to their house.

You can run 3/4" PVC conduit (using 1" will be easier to tool) under ground, then pull 10 AWG THWN (8AWG recommended for long distance) wires. That will be 4 wires (white, green, red, black) to pull.
You could also use UF-b for direct burial, but conduit will be a better option.

Install L14-30 generator inlet on the generator end, install the other end to the breaker panel through 30A breaker and lock out kit, or install a transfer switch.

Generator cord will be 4 wire.


If you want this generator to be a standby generator, you will have to get an automatic transfer switch and somehow wire the generator start signal to start the generator.
This generator uses gasoline and gasoline goes bad very fast. Converting over to propane may be better for standby uses.
 
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Old 06-20-19, 03:08 PM
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The killer is the voltage drop at 200ft distance. If it was me I'd use 1" conduit with aluminum wire, three #4 XHHW-2 and one #6 XHHW-2 for the ground. You would need to down size to #10 or maybe #8 at the 30A power inlet to make connections. I'm not sure what the max size conductor that will fit in a 30A power inlet.
 
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Old 06-21-19, 07:56 AM
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I'd also be concerned that a "well ventilated building" is actually carbon monoxide "safe" for running a generator.
 
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Old 06-21-19, 08:16 AM
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Edited per Pattenp remark below. My bad.
However,
I've had generators all my life and you do not want to place it 200 feet from the house. You will regret it the first time you need it. Winter blizzards, summer heat waves, lighting storms, are when the power goes out. Just checking fuel levels becomes a burden. Place it as near as possible to your house.
 

Last edited by airmark; 06-21-19 at 09:11 AM.
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Old 06-21-19, 08:39 AM
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How do you figured that the 30A outlet will only deliver 3000W? It's 240V and that's 7200W.
 
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Old 06-21-19, 03:14 PM
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Specs on the generator is 8KW running, 10KW peak according to the link provided.
 
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Old 06-25-19, 01:23 PM
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Sorry for the late reply, just got back in town, Northern Ca. near the Oregon border:
After I read all your posts I changed my mind about where I'll place the generator, then re-measured and it came in at just under 100' away

Lambition,TolynIronhand,pattenp,airmark,patmurphey

I understand, I should have been more specific when calling my setup a "Standby Generator", I do know the difference, for me it was easier to explain what I needed by saying that.
Basically, I want to setup my system so that during an outage, 1.) I can walk to my electrical panel, 2.)flip the lockout switch, 3.) turn off all the breakers, 4.) walk over start generator 5.) walk back over to panel and 6.) slowly switch on the breakers (high load first) and whatever other breakers the generator will adequately handle.

Originally Posted by Lambition View Post
That generator has 30A 120/240V twist lock outlet and this is what most people use to hook up a portable generator to their house.
You can run 3/4" PVC conduit (using 1" will be easier to tool) under ground, then pull 10 AWG THWN (8AWG recommended for long distance) wires. That will be 4 wires (white, green, red, black) to pull.
You could also use UF-b for direct burial, but conduit will be a better option.
Install L14-30 generator inlet on the generator end, install the other end to the breaker panel through 30A breaker and lock out kit, or install a transfer switch.
Generator cord will be 4 wire.
If you want this generator to be a standby generator, you will have to get an automatic transfer switch and somehow wire the generator start signal to start the generator.
This is exactly the information I was looking for, if you would recommend a change based on the new shorter distance I will certainly incorporate it, otherwise I'll just go with this.

Originally Posted by Lambition View Post
This generator uses gasoline and gasoline goes bad very fast. Converting over to propane may be better for standby uses.
I am going to add this project in the near future, there's a youtube vid describing the conversion and the generator make is are nearly identical to mine, and although he's converting to natural gas, the propane conversion process and kits are similar; Youtube Link and the guy's really detail orientated, which I like.

Thanks against to all!!!
 
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Old 06-25-19, 01:41 PM
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Even at 100' I would still probably upsize to #8 instead of #10. It's right on the border, but small generators usually aren't great at regulating voltage anyway, so might as well help it out where you can.

The two big challenges with gas generators are keeping the carb clean and making sure you have supply of fresh gas. The carb is more an attention to detail item in that every time you run the generator you have to make sure to empty the fuel tank, drain the bowl and run it dry; or the stale gas will varnish up and ruin it. Some people also like to fog it a little bit with oil for long term storage. Access to fresh gas really depends on where you live and how confident you are the local gas stations will be accessible during a power outage. Gas really only keeps for a month or two so long term storage is tough. Additives like Stabil will extend that to several months, but still not really long term. Some people keep a couple 5 gallon cans around and just cycle them through your mower/car and refill to keep them fresh, but that can be a hassle loading and unloading cans every month. Propane keeps forever, but may also be much harder to refuel during an emergency if your tank(s) run out. A big advantage of propane or natural gas is that you can test fire your generator on a regular basis without having to drain back the fuel system, as it is also not great for the generator to sit long periods without running.
 
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Old 06-25-19, 03:27 PM
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I converted my Generac to propane and it is really nice not having to deal with gas. The downside with propane is the power output to fuel cost is higher.
 
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Old 06-26-19, 12:42 PM
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I have a 110 gal propane tank for heating my home, plus a 30 gal I picked up for extra measure also a few barbecue tanks.The ratings from Consumer Reports is what sold me on this model Generac, unfortunately it didn't come with the dual fuel option, thus the need to install a kit. Because of the recent fires in CA, PG&E has sent out notices that they may turn off power in extreme heat and wind situations, for threat of fire. I'm preparing for that eventuality or any outage.
Originally Posted by ibpooks
Even at 100' I would still probably upsize to #8 instead of #10. It's right on the border, but small generators usually aren't great at regulating voltage anyway, so might as well help it out where you can.
I haven't finalized my placement of the generator, but when I do I'll definitely consider yours and all others suggestions.
My main concerns are safety and the security of its placement, I don't want anyone being overcome from carbon monoxide poisoning, nor do I want to hurt persons hears from the sound while it's running, and lastly I want it still being where I stored it when I need it. And of course it go without saying, that it meets my power needs during an outage.:-)


Steep
 
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Old 06-26-19, 04:39 PM
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I would keep the generator within 50ft and run 10 gauge wire.
Test how loud your generator really is and keep it close as possible to your home. Many high end generators are fairly quiet.

Personally, I would have gotten actual standby generator with automatic transfer switch. If not too late, get a standby generator.
These are cheapest I can find, although getting larger one will be better.
https://www.lowes.com/pd/Generac-Pow...tch/1000815538

https://www.lowes.com/pd/Briggs-Stra...witch/50197715


If you choose to use portable generator, since you already have propane, I would look into propane conversion kit and run pipe down to the generator as well. Emptying gasoline out of generator is not too hard, but keeping fresh gasoline all the time will be difficult.
 
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