What size wire?

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Old 08-21-16, 02:54 PM
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What size wire?

Hello: Newbie to site and have some knowledge in electrical work. I live in Clay county Florida. I am trying to install a gate opener in front of the house which is 320 ft from the nearest source of electricity (garage). My question is:

What size wire do I need to use to install an outlet to the gate (320 feet away) in order to avoid or at least minimize a drop in voltage?

Do I need to use a UF-B wire if I am using conduit or would NM-B wire do and how deep should it be buried under ground?

Thanks in advance for the advice.
 
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Old 08-21-16, 02:57 PM
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How many amps does the opener need?

UF is a pain to pull in conduit. Better to use individual THWN conductors in conduit. NM cannot be used outside.
 
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Old 08-21-16, 03:15 PM
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In addition, if you plan on conduit, you can probably buy 10 gauge THWN in 500' reels as cheaply as you can the UF. You'll need Black/white/green, so 3 rolls at about $65 per roll depending on location.
 
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Old 08-21-16, 04:01 PM
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Do I need to use a UF-B wire if I am using conduit
Yes but best practice is individual wires because UF-b would be a PITA to pull.
would NM-B wire do
No. NM-b can only be used in dry location. Buried conduit is a wet location because it will usually eventually fill with water.
and how deep should it be buried under ground
18" for conduit. 12" if 120v at 20 amps or less and GFCI protected at source.

But do you need to run a line? Most gates are operated by a 12v battery. The AC is only to run a charger. There are solar panel chargers for gates which will do the same. No AC required. Might be cheaper/easier.
 
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Old 08-21-16, 04:05 PM
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The opener just needs a low voltage transformer to charge a 12 volt battery which is the main source of power for the gate opener.

Do you all think a 10 gauge THWN is enough to minimize the drop in voltage due to the length of the wire?
 
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Old 08-21-16, 04:07 PM
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As I said you can use a solar panel. No AC needed.
 
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Old 08-21-16, 04:09 PM
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Ray: You are right. The opener kit comes with a solar panel to charge to battery but I also plan to power a couple of lamps and perhaps low voltage LED lights in the future.
 
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Old 08-21-16, 04:12 PM
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Do you all think a 10 gauge THWN is enough
At 5 amps voltage drop would be close to the 3% "sweet spot". Even at 10 amps the drop would only be about 6.7%.
 
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Old 08-21-16, 04:17 PM
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what is the difference between THWN and THHN?
 
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Old 08-21-16, 04:21 PM
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The W signifies water resistance. Most wiring comes as THWN/THHN now.
 
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Old 08-21-16, 04:21 PM
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THWN has the connotation for "Water" repellency, which THHN has as well, and you will probably only find THHN, anyway. It is fine.
 
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Old 08-21-16, 04:23 PM
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"Water" repellency
It is not water repellent, it is water resistant.
 
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Old 08-21-16, 04:26 PM
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THWN is for wet conditions. THHN for inside use but the point is mostly moot because almost all wire is dual rated THHN/THWN. BigBox stores often incorrectly call dual rated wire THHN in their ads so you just need to check what is printed on the wire.

Have you determined a solar panel isn't for you?
 
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Old 08-21-16, 04:30 PM
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It is not water repellent, it is water resistant
Well golly gee, if it is resistant to water, it obviously repels it
 
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Old 08-21-16, 04:31 PM
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I am going to hook it to solar panel first but the area does not get much sun so I need the reassurance of having AC charger available in case the battery dies due to lack of sunlight. Plus, I also plan to power a couple of lamps and LED lights.
 
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Old 08-21-16, 04:55 PM
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Sounds like you have a good plan.
 
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Old 08-21-16, 05:01 PM
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Ray: I tried to google THHN 10/2 wire with ground but I cannot seem to find it. Do you know if it is available?
 
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Old 08-21-16, 05:11 PM
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THHN is not an assembled cable, it's single wire. Look for THHN/THWN in size #10.
 
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Old 08-21-16, 05:21 PM
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THHN/THWN #10 is an assembled cable with black. red and bare wire?
 
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Old 08-21-16, 05:27 PM
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No THHN/THWN #10 is individual wires. Easier to pull in conduit. You'll need a hot, neutral and ground. Southwire 500 ft. 10 Green Stranded CU THHN Wire-22977357 - The Home Depot
 
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Old 08-21-16, 05:31 PM
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oh i see... thanks chandler, ray and everyone for the help
 
 

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