what type of conduit to run AC lines underground?

Jayne

Jayne

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Having some trenching done for a plumbing issue and while they're digging they've agreed to go deeper so I can run an electrical conduit in the same trench below the water line for the electrical project I'll have in the same area but at a much later time.

Question is, what type of conduit do I actually run? I've been using some low pressure sprinkler line stuff from Home Depot to run ethernet cables through, but the electrical will be legit 240v stuff, not low power cables that aren't dangerous should the conduit fail in some way.

This? https://www.homedepot.com/p/AFC-Cab...llic-Liquidtight-Conduit-6002-30-00/202286688

Ridgid schedule 40 stuff looks clumsy and expensive and I know it will leak somewhere if I've got to make that many connections.
 
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Schedule 40 PVC is what is required unless you want to run rigid steel conduit. There used to be some applications where EMT could be run underground with compression fittings but I wouldn't do it.
 
I'llBeYourHuckleberry said:
Why not just use direct burial wire?
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Cerrowire's Gray 250 ft. 12/3 Solid CerroMax UF-B Cable can be used in applications that include outside lamp posts, pumps, and other loads outdoors, underground and in wet areas. It can also be used for outbuildings such as garages and barns. 12-gauge copper wire is UL listed. PVC jacketed with...
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The trench will be dug months before the wire goes in.
 
Jayne said:
Having some trenching done for a plumbing issue and while they're digging they've agreed to go deeper so I can run an electrical conduit in the same trench below the water line for the electrical project I'll have in the same area but at a much later time.

Question is, what type of conduit do I actually run? I've been using some low pressure sprinkler line stuff from Home Depot to run ethernet cables through, but the electrical will be legit 240v stuff, not low power cables that aren't dangerous should the conduit fail in some way.

This? https://www.homedepot.com/p/AFC-Cab...llic-Liquidtight-Conduit-6002-30-00/202286688

Ridgid schedule 40 stuff looks clumsy and expensive and I know it will leak somewhere if I've got to make that many connections.
Click to expand...

Pretty much any conduit you run is either going to leak or get moisture and condensation in there. Whatever you run, use direct burial cable anyway. Unless you don’t care how long it lasts.
 
Yeah your only two legit choices are schedule 40 PVC or UF cable. Period.

How many amps will your project require? Current (amps) determines the size of the wire. The size of the wire determines the size of the conduit.

I haven't been an electrician for years. But when I was the rule was 60% fill (I believe). That means the wire can only take up 60% of the conduit interior. A real electrician will correct me if I'm wrong.

As such, if you don't know what size wire you will need, I would run no less than 1 1/4", if not 1 1/2".

If you're worried about leaking and/or your ability to install the conduit properly, either dig another trench later and go direct burial or pay somebody to do the conduit now. PVC is cheap. If the trench is dug, any electrician worth a dang could run 300ft of it in no time flat. Getting the conduit to the job and laying in out beside the trench should literally take longer than running it.

The stuff can literally be cut with a string, burs cleaned with a pocket knife, bent with a heat gun, and is overall super easy to work with.
 
two fingers said:
Yeah your only two legit choices are schedule 40 PVC or UF cable. Period.

How many amps will your project require? Current (amps) determines the size of the wire. The size of the wire determines the size of the conduit.

I haven't been an electrician for years. But when I was the rule was 60% fill (I believe). That means the wire can only take up 60% of the conduit interior. A real electrician will correct me if I'm wrong.

As such, if you don't know what size wire you will need, I would run no less than 1 1/4", if not 1 1/2".

If you're worried about leaking and/or your ability to install the conduit properly, either dig another trench later and go direct burial or pay somebody to do the conduit now. PVC is cheap. If the trench is dug, any electrician worth a dang could run 300ft of it in no time flat. Getting the conduit to the job and laying in out beside the trench should literally take longer than running it.

The stuff can literally be cut with a string, burs cleaned with a pocket knife, bent with a heat gun, and is overall super easy to work with.
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^^^ This.

it should not be that hard to get a good glue joint on the conduit. The main thing is to avoid sharp bends in the run, as they can make it very difficult to pull wire.

Do you have any idea what your future power needs will be? knowing that will assist with the conduit sizing.
 
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If you run conduit make sure to put string in it to pull a rope, which will pull your wire. But I would skip the conduit. It is only needed to protect the wire in rocky soil.

I would go ahead and put underground wire in the ditch. Where the wire comes up, leave enough extra wire to work with. Tape the end well. Fold it and slide a piece of conduit down. Cap on end. Back fill. When ready to hook up, pull the conduit piece out and there's your wire.
 
Scsmith42 said:
Do you have any idea what your future power needs will be? knowing that will assist with the conduit sizing.
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I'm thinking 2, 240v circuits. One that would stay 240v in case I wanted to run the welder or some such, and the other to be broken out into some 120v circuits. one for overhead lighting, one for outlets. Or maybe 2 for outlets, so I would need 60A 240v on that second one, 30A 240v on the first.

Might it be cheaper and easier to just run the direct burial wire and skip the conduit entirely? I honestly just figured direct burial was a shortcut and wouldn't last, but if it's actually the right way to go....?
 
If you must lay pipe, put in WAY more pipe than you will ever need, put in a pull string, and instead of 90’s at each end, use back to back 45’s.

OR

Use direct bury power cable and put in a 2” pipe for data/CAT 5 cable or phone lines


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Jayne said:
I'm thinking 2, 240v circuits. One that would stay 240v in case I wanted to run the welder or some such, and the other to be broken out into some 120v circuits. one for overhead lighting, one for outlets. Or maybe 2 for outlets, so I would need 60A 240v on that second one, 30A 240v on the first.

Might it be cheaper and easier to just run the direct burial wire and skip the conduit entirely? I honestly just figured direct burial was a shortcut and wouldn't last, but if it's actually the right way to go....?
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Direct burial is not a shortcut at all. @Jayne while the trench is open and knowing you, I’d get some direct burial cat6 for your camera drops.

www.truecable.com

Cat6 Direct Burial Ethernet Cable｜Shielded

High-performance direct burial shielded Cat6 cable. Rugged and durable for extreme outdoor environments. Shop bulk supplies online at trueCABLE.
www.truecable.com www.truecable.com
 
You'll just put one run of wire to your building. 120/240 will both come from it. Just need wire large enough to carry the load at that distance.
 
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Several years ago, my neighbor had a fire in his outbuilding. When the damage was cleaned up and repaired, the service wire in the shed had burnt down too short to remake the connections.
His direct buried wire also shared a trench run with other piping, but not in PVC, so he ended up having to trench a different spot and re run his service.
This time he put in PVC so if there was ever another problem, he could just pull the old wire out and new wire in.
FWIW, even though Ive never had an issue, Ive always put my wire in PVC for that same reason, too.
 
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draco88 said:
Several years ago, my neighbor had a fire in his outbuilding. When the damage was cleaned up and repaired, the service wire in the shed had burnt down too short to remake the connections.
His direct buried wire also shared a trench run with other piping, but not in PVC, so he ended up having to trench a different spot and re run his service.
This time he put in PVC so if there was ever another problem, he could just pull the old wire out and new wire in.
FWIW, even though Ive never had an issue, Ive always put my wire in PVC for that same reason, too.
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New trench was not necessary unless the wiring is what caused the fire. Wire can be spliced underground.
 
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"Watching" this one...I'm about to have the same need (mine will be a 150' run, 200 amps, which is probably overkill)
 
Conduit is most beneficial for preventing cuts...or at least giving the person digging a pre-warning. It's OK if water gets in the line, as long as the wire is a continuous run or has been shrink-wrapped over the splices.
 
amnesia said:
Direct burial is not a shortcut at all. @Jayne while the trench is open and knowing you, I’d get some direct burial cat6 for your camera drops.

www.truecable.com

Cat6 Direct Burial Ethernet Cable｜Shielded

High-performance direct burial shielded Cat6 cable. Rugged and durable for extreme outdoor environments. Shop bulk supplies online at trueCABLE.
www.truecable.com www.truecable.com
Click to expand...

I was thinking that myself. The power goes down 2' (or 3'?), then they back-fill to run the water pipe at 1' and with that water I could run the ethernet. Gotta keep a 1' separation from the high power lines or it will mess with the ethernet.

I hand dug a weak ass trench out there for the current ethernet, but having a backup line done right while the trench is there seems like a good idea.
 
9outof10mms said:
Conduit is most beneficial for preventing cuts...or at least giving the person digging a pre-warning. It's OK if water gets in the line, as long as the wire is a continuous run or has been shrink-wrapped over the splices.
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Between the barns we ran a wide trench (dug with a backhoe bucket) and ran power on one side and networking on the other. I filled the trench with a bunch of scrap brick, rock and other stuff before we put the dirt back so that at some future point if someone starts randomly digging in the paddock they'll at least hit a nice layer of hard stuff before they find my conduit. (which is probably the wrong type, but I didn't know then or think to ask like this time).
 
Jayne said:
Between the barns we ran a wide trench (dug with a backhoe bucket) and ran power on one side and networking on the other. I filled the trench with a bunch of scrap brick, rock and other stuff before we put the dirt back so that at some future point if someone starts randomly digging in the paddock they'll at least hit a nice layer of hard stuff before they find my conduit. (which is probably the wrong type, but I didn't know then or think to ask like this time).
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if you haven’t planned on it, I would recommend laying this a foot or so above the wire or conduit
ideal-electrical-tapes-42-101-64_145.jpg
Ideal 3 in. x 1000 ft. Buried Electrical Line Caution Tape


See this on Homedepot.com
OMSID#: 202276217
 
Jayne said:
I'm thinking 2, 240v circuits. One that would stay 240v in case I wanted to run the welder or some such, and the other to be broken out into some 120v circuits. one for overhead lighting, one for outlets. Or maybe 2 for outlets, so I would need 60A 240v on that second one, 30A 240v on the first.

Might it be cheaper and easier to just run the direct burial wire and skip the conduit entirely? I honestly just figured direct burial was a shortcut and wouldn't last, but if it's actually the right way to go....?
Click to expand...

So you need 100A wire.

First thing you need to find out is if you can even subfeed another 100 amps from your main panel. I would hate for you to bury wire only to find out you can't subfeed from your panel.

Post pics of your main panel here. Post the piece of paper glued inside the door. Then post a pic showing all the breakers in there now. A qualified electrician here can tell you if a licensed electrician would even tie into that panel later.

We're building a "hangout" in our back yard that will have a full kitchen. So we're going through the se thing.
 
Grey electrical pvc buried 18” or more. Plumbing is 24” here. Size depends on wireYou will be safe at 1.5” pipe. You only need to run 2 current wires and a ground later for both 240 and 120 for a panel.

That red tape mentioned above is a great idea IF you cover dirt in the trench with the caution tape 6” below grade. If not the conduit is most likely going to protect digging. Personally I would not drop both in the same trench but it is more cost effective. If you have a plumbing issue that needs digging a locator will mark it and most plumbing companies will not touch that job.

Direct burial wire needs to be 24” depth.
 
Jayne said:
Having some trenching done for a plumbing issue and while they're digging they've agreed to go deeper so I can run an electrical conduit in the same trench below the water line for the electrical project I'll have in the same area but at a much later time.

Question is, what type of conduit do I actually run? I've been using some low pressure sprinkler line stuff from Home Depot to run ethernet cables through, but the electrical will be legit 240v stuff, not low power cables that aren't dangerous should the conduit fail in some way.

This? https://www.homedepot.com/p/AFC-Cab...llic-Liquidtight-Conduit-6002-30-00/202286688

Ridgid schedule 40 stuff looks clumsy and expensive and I know it will leak somewhere if I've got to make that many connections.
Click to expand...
"Below the water line" Water isn't an issue. If the cable is rated for burial it doesn't matter. You bury it to depth to avoid it being hit by digging. You put it in a conduit to further protect it. Water is not an issue thank goodness or all those transatlantic dealios would be in a fix.
 
I much prefer conduit to direct bury wire because it provides the most flexibility long term to changing power needs.
 
Goofyfoot2001 said:
"Below the water line" Water isn't an issue. If the cable is rated for burial it doesn't matter. You bury it to depth to avoid it being hit by digging. You put it in a conduit to further protect it. Water is not an issue thank goodness or all those transatlantic dealios would be in a fix.
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by water line I meant the pipe that's carrying the water.
 
two fingers said:
So you need 100A wire.

First thing you need to find out is if you can even subfeed another 100 amps from your main panel. I would hate for you to bury wire only to find out you can't subfeed from your panel.

Post pics of your main panel here. Post the piece of paper glued inside the door. Then post a pic showing all the breakers in there now. A qualified electrician here can tell you if a licensed electrician would even tie into that panel later.

We're building a "hangout" in our back yard that will have a full kitchen. So we're going through the se thing.
Click to expand...

So here's the story:

Out in the barn where I want the 'new' power there is currently a sub panel with 3x 20A 120v breakers in it. That panel is fed from the main panel in the house by 2x 20A 120v breakers. There are only 4 wires going to the barn, and when we had a generator switch panel wired into the house, the electrician said "I'm not touching that" when it came to the barn feed/panel. That makes me think it's hokey as crap.

The water line out to the barn is leaking, and so we're going to replace it. The current power runs with that current leaking water. I first want to deal with the water, then the power, but I want it as two projects. We're not touching the original water line, so the original power line can just continue to be there until I'm ready to tackle the new electrical.

In the barn, I've extended one of the (presumably sketchy) circuits to 2 other structures (goat barn and chicken coop) to run LED lights and some cameras. It's a lot of outlets, but drawing very little power. I think with everything turned on everywhere I can pull 450 watts at most. It's been running that way for 5 years. Off one of the other circuits is the existing outlets in the barn which has powered a table saw, chop saw and skill saw for years now as well. Haven't ever had any breaker issues (or fires).

There are no open spots in the main panel. I noticed some of the breakers are those half sized ones where you get two-in-one physical spot. I had hoped that between the 2x 20A we would be reclaiming and switching some of the singles to doubles it would free up enough physical panel space, or just drop a single larger breaker in. 100A extra may be too much, but if I have enough wire to carry it and then later learn it's not possible then I will just have to downgrade what's wired at the sub panel. With the reduction in lighting from incandescent to LEDs everywhere the actual load on the house is way down vs. when it was remodeled, but that's probably not relevant.

My major concern here is that I bring in an electrician and get the "oh my god you must burn everything down and replace everything everywhere!" story vs. the "this is actually unsafe and needs to be fixed but this other stuff is good enough". That's what keeps me from calling in real help, and has left this situation as it is for the last 7 years. Get it safe, but if we can't plug hair dryers in everywhere without breakers popping I'm OK with that. I can be smart about what gets deployed where.
 
I may have missed the answer, I asked how long a run from the main panel to the barn? Do you have 200 amp service on your main panel?
Photos will help get you the right answers.
 
two fingers said:
Post pics of your main panel here. Post the piece of paper glued inside the door. Then post a pic showing all the breakers in there now. A qualified electrician here can tell you if a licensed electrician would even tie into that panel later.
Click to expand...

The blue tape marks the circuits that are wired to the generator switch panel.

IMG_9493.JPGIMG_9494.JPGpanel2.jpg
 
CZfool68 said:
@Jayne you better burn it down and install overkill so you’ll be able to handle that future CNC machinery. 👍
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1613606018506.png

But seriously, no. Turning the barn into a CNC shop is not an option. It's cold out there, and I know people with climate controlled shops with lots of tools...
 
LeeMajors said:
Unless you have ALOT of breakers feeding 2 or 3 receptacles, I don't see getting another 100 amp feed out of that.
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They way the previous owners had things wired during the remodel, some feed like 20 receptacles, and some feed... zero. I've had one breaker off for a year or so now, we still don't know what doesn't work.

That makes me think we've got 60A available between that off one and the 2 existing barn feeds. better than nothing.
 
LeeMajors said:
Unless you have ALOT of breakers feeding 2 or 3 receptacles, I don't see getting another 100 amp feed out of that.
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Yeah me either.

I would hit up a licensed electrician before proceeding. You might find that you're not allowed to subfeed another 100 amps off of that full panel.

Mine looks just like it. Full up.

What we're having to do is upgrade the main feed to 400 amps, and split at the meter to the main house and the hangout (which will essentially be a small house in our back yard by the pool).

Like I said, it was years ago when I was an electrician. Don't take my word for it. Simply ask a current (pun intended) licensed electrician before wasting a lot of money.
 
I do know code won't allow a 100 amp feed from that panel. If you are getting an inspection. I wouldn't feed another 60 amp double to feed an outbuilding if it were me.

You could hang a meter can and a proper panel for what the wire and conduit will cost to feed the barn. Just have 2 power bills


Jayne said:
The blue tape marks the circuits that are wired to the generator switch panel.

View attachment 305200View attachment 305201View attachment 305204
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two fingers said:
Yeah me either.

I would hit up a licensed electrician before proceeding. You might find that you're not allowed to subfeed another 100 amps off of that full panel.

Mine looks just like it. Full up.

What we're having to do is upgrade the main feed to 400 amps, and split at the meter to the main house and the hangout (which will essentially be a small house in our back yard by the pool).

Like I said, it was years ago when I was an electrician. Don't take my word for it. Simply ask a current (pun intended) licensed electrician before wasting a lot of money.
Click to expand...
 
Agree with others, you need a real electrician to do a checkout of your panel, you have a GE panel with GE, Siemens and Eaton BR breakers in it.
 
two fingers said:
Yeah me either.

I would hit up a licensed electrician before proceeding. You might find that you're not allowed to subfeed another 100 amps off of that full panel.

Mine looks just like it. Full up.

What we're having to do is upgrade the main feed to 400 amps, and split at the meter to the main house and the hangout (which will essentially be a small house in our back yard by the pool).

Like I said, it was years ago when I was an electrician. Don't take my word for it. Simply ask a current (pun intended) licensed electrician before wasting a lot of money.
Click to expand...
Exactly right. Listen to this man.

Ive never been a licensed electrician but I’ve pulled a couple million miles of wire and installed a billion switches and receptacles for my licensed FIL. He was the electrical contractor on over 600 Carl’s Jr./Hardee’s and a 400 room hotel in California. That was the stuff I worked on. He did a lot more other projects in 50 some years in the business.

That panel looks to be maxed Amp wise.
 
If the circuits that went to the blue taped breakers now go to a generator sub panel, aren’t the blue taped breakers not in use?
 
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