How do I run power to detached garage?

[Briar Rabbit]

I'm not aware of any listed conduit that is made from polyethylene. PVC is about the only thing out there.


Nonsense.

Maybe notorius is too strong an adjective but aluminum wiring can fail more frequently when compared to copper in an underground application.

What are the dangers of aluminum wiring?
The biggest danger with aluminum wiring is that fire hazards occur from the oxidation and deterioration caused at the termination points. This can cause overheating and arching that will trip a circuit breaker, but can also cause a fire.
Reference: mdcelectric.ca/aluminum-wiring-dangers/

I have never had a fire but definitely have had aluminum wire in underground applications that had to be replaced when it failed. Poly may not be approved for conduit in some codes but not all underground wire is buried in conduit. And where it is not required by code I use poly to facilitate additional wiring needs for the future or wiring replacement in addition to preventing rodent issues.

 

[flyingron]

The termination point is not going to be UNDERGROUND or in any conduit. Yes, aluminum requires special consideration at terminations, but that in no way supports your statement.

You can say all you want but your recommending things that are ILLEGAL any place that adheres to the NATIONAL ELECTRICAL CODE. You also risk insurance issues using unlisted material in your wiring installations.

This is like telling people it's OK to fly over gross, or to omit fuel reserves.

 

[Briar Rabbit]

The termination point is not going to be UNDERGROUND or in any conduit. Yes, aluminum requires special consideration at terminations, but that in no way supports your statement.

You can say all you want but your recommending things that are ILLEGAL any place that adheres to the NATIONAL ELECTRICAL CODE. You also risk insurance issues using unlisted material in your wiring installations.

This is like telling people it's OK to fly over gross, or to omit fuel reserves.

Ron, You can believe what you want but I have had personal experience with aluminum wire buried underground that degraded and had to be replaced without being in the area of a termination point. Not all local codes require underground wiring to be inside conduit. And poly is better than nothing, actually works pretty well on the farm. I am not suggesting it over an application that requires adhering to a NEC code.

 

[Stewartb]

Call an electrical contractor, get a permit, have a pro do the job.

 

[weilke]

Just do what everyone locally seems to do: Plug an extension cord in an indoor outlet, then feed it out of a window and string it to the outbuilding. If it's not long enough, just buy another cord and connect the two with a knot. Don't forget 'electricle tape' to make it all professional.

 

[JOhnH]

Call an electrical contractor, get a permit, have a pro do the job.

What makes you think that isn't what I plan to do?

All I am doing here is gathering information so I can make better decisions.

 

[Albany Tom]

Re conduit, if you use cable rated for direct burial, you can also run it in any type of tubing you want, conduit or not. If you run individual wires, or as I understand it cable not rated for direct burial, then if you put it in conduit it has to be actual electrical conduit. Or at least that's my understanding, as a guy on the Internet.

If it were me, I'd run 8/3 UF cable in a 1.5" or better PVC conduit. Put a sub panel in the garage and you'll have plenty of power for normal garage stuff. This is assuming you don't need to run a big ac unit all the time, and you don't have to run more than one of: welder, big woodworking tools, big metalworking tools, compressor, at the same time. If you're looking to setup a fully equipped machine shop or wood working shop, you probably want more power. Oh, and assumes you're not running electric heat. If you have any of that stuff, then add up all of what you want to run at once, add lights/heat/etc, bump it up 20% and go from there.

Meeting NEC is always a good idea, but not every place in the US requires pulling a permit, hiring a licensed electrician, or getting an inspection. Some places, though, require all of that.

 

[flyingron]

You can't just stick any cable in conduit. It still has to be rated for wet locations. You can run cable in conduit if you want, but it's a pain in the butt. I'd run THWN.

The NEC even if it isn't required is a good idea. You're talking about electrical and fire safety here, and you don't want to be explaining to your insurance guy why you have installed an improper cob job rather than using listed equipment.

 

[Gary Ward]

Just do what everyone locally seems to do: Plug an extension cord in an indoor outlet, then feed it out of a window and string it to the outbuilding. If it's not long enough, just buy another cord and connect the two with a knot. Don't forget 'electricle tape' to make it all professional.

lol

 

[Gary Ward]

Ron, You can believe what you want but I have had personal experience with aluminum wire buried underground that degraded and had to be replaced without being in the area of a termination point. Not all local codes require underground wiring to be inside conduit. And poly is better than nothing, actually works pretty well on the farm. I am not suggesting it over an application that requires adhering to a NEC code.

I knew my comment about aluminum wiring would turn some heads.

I am not a electrician but have had a lot of electrical work done here at work. All I know is I have seen aluminum wiring in new panels I have had installed. Just the feed lines all else is copper. Pretty sure the wiring coming from the electric company into our panels are aluminum. I have been using a long time professional electrician for 30 years now. He has helped me build 2 petroleum bulk plants and several buildings over the years and all of it has been inspected and approved. No problems yet with wiring. I know they use a liquid coating on the wiring ends to prevent corrosion I think? It is dark in color and you can see it in the connections.

 

[cowman]

I have a large detached workshop about 300' away from my house. Due to terrain, running new service to it was going to be costly. We installed a 100amp breaker in the house and ran some heavy aluminum wire inside a buried conduit up to it.

I've had this setup for several years now. I have a welder, big 220v air compressor, and various power tools up there. I have never had any electrical issues, it works great.

 

[NoBShere]

I echo the sentiment to follow local codes from a safety, reliability, resale and "don't want to do it again" standpoint. permits, different topic, not against them but, they are a different topic. With that being said, if you have ever seen the electrical distribution systems in developing nations, you would think it would be very hard to screw up a simple detached garage.

Your job is simple. Others have mentioned 100 amp sub or a 50 amp sub. I see both as working. The 100 amp sub is future proofing the service to your garage given that you mentioned possibly adding an EV charger (although you will most likely not be charging during the day...) A lot of detached garages run off a 50 amp service although I am in different area that doesn't "require" AC so maybe 70amp? Once you pick an arch or contractor, they can provide local experience. And the distance, isn't that far. I like the idea of in-ground conduit from primary to outbuilding as it makes it easier to upgrade/add without messing with landscape/hardscape if the need arises making it a bit of a compromise on the future proofing concept. Some go as far as to add an extra unused conduit because its relatively cheap to do. Just watch the fill percent on conduit. Future proofing is expensive right now and when you think about how contractors get paid (x% of material costs on top of labor), they love future proofing. Not bashing contractors, maybe they are right because who knows if the material costs will actually go back to normal.

Btw, here is the florida code. Your area may have some special requirements but, this should be close. https://up.codes/viewer/florida/fl-residential-code-2014/chapter/38/wiring-methods#38 Apologies for the long windedness. Definitely some things to think about but, its a small job that is important to you.

 

[weilke]

6 months from now another thread: How do I get wifi into my detached garage

When you put in a conduit, keep in mind that there are restrictions on what else you can run in there (and what ratings that 'else' has to have). If you want to run network cable to the garage, you may or may not be allowed to pull that alongside the feeder line . If it needs to be inspected, you may have to stick with a pull-string and wait for the cable fairy to pull the network cable through the conduit once the inspector has left.

Even if your local jurisdiction is lax on electrical permits, if you expect that you or your heirs will sell the place one day, you definitely want to do it in a way that can pass inspection. As useless as home inspectors are, anything that is 'not up to code' has a potential to hold up a transaction.

 

[3393RP]

You can't just stick any cable in conduit. It still has to be rated for wet locations. You can run cable in conduit if you want, but it's a pain in the butt. I'd run THWN.

The NEC even if it isn't required is a good idea. You're talking about electrical and fire safety here, and you don't want to be explaining to your insurance guy why you have installed an improper cob job rather than using listed equipment.

I'm a licensed electrician, and this is about the best advice I've seen in a thread with serious misinformation.

A 150' underground circuit in conduit will not experience significant voltage drop. Using NEC calculations, a 150' 100 amp branch circuit in conduit with #1 AWG copper conductors will have less than a 2% voltage drop.

 

[3393RP]

When you put in a conduit, keep in mind that there are restrictions on what else you can run in there (and what ratings that 'else' has to have). If you want to run network cable to the garage, you may or may not be allowed to pull that alongside the feeder line . If it needs to be inspected, you may have to stick with a pull-string and wait for the cable fairy to pull the network cable through the conduit once the inspector has left.

Placing any type of communications wiring in a conduit containing current carrying conductors is prohibited by the NEC (and common sense).

Don't offer advice when you don't have a clue what you're talking about. When dealing with electricity, such nonsense could cause fires, injury, and death.

 

[Albany Tom]

There's probably no reason to run low voltage in the same space as electrical cable today. In the late 80's to maybe 90's, it was common, accepted, and code compliant to run NEC class 2 wiring - data - alongside power cables (NM-2) in commercial wiring. In that case, the PVC piping was not a conduit, because NM doesn't need that, but rather a route for the wires. Underground, you'd run UF, because it's wet rated. But again, these days, no reason to do that, and not sure if it's still code compliant. If you need wi-fi, run that through the air.

Aluminum is common for service entrance, and industrial, but I wouldn't run it in a residence. Not because it isn't safe, but because there's a history associated with it that's just negative, because installed improperly and terminated at an outlet in a wall it caused problems. From panel to panel it's a non-issue, but the perspective buyer is going to see "aluminum wiring" flagged as an item by the home inspector, or at least there's a good chance of that.

#1 copper would work great, but price that out first. That's enough amperage to run a Ferris wheel.

 

[3393RP]

There's probably no reason to run low voltage in the same space as electrical cable today. In the late 80's to maybe 90's, it was common, accepted, and code compliant to run NEC class 2 wiring - data - alongside power cables (NM-2) in commercial wiring.

#1 copper would work great, but price that out first. That's enough amperage to run a Ferris wheel.

Class 2 wiring is power and voltage limited circuits (like signaling and alarm circuits) that meet certain requirements for power supply ampacity, wire insulation, and conductor size, not data cabling.

Data cabling is now organized under Article 800 of the 2020 NEC. Ethernet and PoE wiring cannot be run in conduits containing Article 300 power circuits.

The 150' 240 volt 100 amp circuit has been mentioned in this thread as a possible source for the garage power. I posted the voltage drop calculations for that circuit as a general example of how circuit length affects voltage drop.

 

[Albany Tom]

Class 2 wiring is power and voltage limited circuits (like signaling and alarm circuits) that meet certain requirements for power supply ampacity, wire insulation, and conductor size, not data cabling.

Data cabling is now organized under Article 800 of the 2020 NEC. Ethernet and PoE wiring cannot be run in conduits containing Article 300 power circuits.

The 150' 240 volt 100 amp circuit has been mentioned in this thread as a possible source for the garage power. I posted the voltage drop calculations for that circuit as a general example of how circuit length affects voltage drop.

All correct of course. Back when I was doing data wiring, to my memory, the only spec for data cabling was applicable to data centers. So the cabling was spec'd to class 2, which worked because the computer equipment limited both the voltage and current supplied. Typically RG-58 variants, sometimes RG-62, and then twisted pair started up. NEC back then was all oriented toward power, again as I remember it, with the telco and cable companies given fairly free reign as long as they didn't route into conduit as you mention. Grounding was an absolute mess, though. Much better now. I think we worked with 1985 NEC as long as we could.

 

[3393RP]

All correct of course. Back when I was doing data wiring, to my memory, the only spec for data cabling was applicable to data centers. So the cabling was spec'd to class 2, which worked because the computer equipment limited both the voltage and current supplied. Typically RG-58 variants, sometimes RG-62, and then twisted pair started up.

Back then I was running token ring and thousands of feet of 1" diameter bus and tag cabling between IBM mainframes, tape drives, and DASD. The guys running fiber optic these days don't know how good they have it.

 

[Albany Tom]

Back then I was running token ring and thousands of feet of 1" diameter bus and tag cabling between IBM mainframes, tape drives, and DASD. The guys running fiber optic these days don't know how good they have it.

Two things I don't look back fondly on are crawling through 2' deep loose fiberglass, and terminating twinax.

 

[weilke]

Placing any type of communications wiring in a conduit containing current carrying conductors is prohibited by the NEC (and common sense).

Don't offer advice when you don't have a clue what you're talking about. When dealing with electricity, such nonsense could cause fires, injury, and death.

I thought the suggestion that someone would have to do this surrepticiously after the last inspector leaves made clear enough that this is not code compliant.
'Common sense' also says that the risk from running a plenum rated cat6 cable next to a 240V cable that is carrying very little load is rather modest. This is not a phone line next to a 15kV utility feeder. The odds of the 100A subpanel feeder failing inside of the conduit and injecting voltage into the communications circuit is practically zero. But yeah, for 'code' he would have to bury a separate conduit (or use fiber for the communications circuit).

 

[Brad W]

I'm no electrician and I can't answer the questions
but if it were mine, some things I'd have on my list to explore
two conduit runs...one for data and one for power...even if you don't have plans for data now, you might want to install an access point there some day
conduit runs would be over sized and have pull strings pulled with the wires for pulling more stuff through easy in the future.
I'd want plenty of empty breaker spaces in the panel, if you will be installing a sub panel out there or upgrading your existing one.
and I'd look into those interlock kits that let you legally feed a generator or big back-up battery (F-150 lightning for example) into the panel in case of power outages or whatever.

 

[flyingron]

I can tell you for practical matters it's near impossible pulling data lines in conduit that has other stuff in it. For this reason, we'd put subducting in for future pulls.

 

[3393RP]

I thought the suggestion that someone would have to do this surrepticiously after the last inspector leaves made clear enough that this is not code compliant.
'Common sense' also says that the risk from running a plenum rated cat6 cable next to a 240V cable that is carrying very little load is rather modest. This is not a phone line next to a 15kV utility feeder. The odds of the 100A subpanel feeder failing inside of the conduit and injecting voltage into the communications circuit is practically zero. But yeah, for 'code' he would have to bury a separate conduit (or use fiber for the communications circuit).

Common sense also realizes that data cabling run into panel board enclosures means someone with little or no training in working around live electrical parts could be injured or killed. A homeowner might feel qualified to do so, and that's why it's non-code compliant and dangerous. Electricity and surreptitious actions don't belong together.

 

[3393RP]

Two things I don't look back fondly on are crawling through 2' deep loose fiberglass, and terminating twinax.

When we bought our house in 1997, we removed all of the drywall in stages and replaced it with new. That allowed me to add receptacles, lighting, and insulation in the walls. I also installed a Leviton data termination cabinet, and ran voice, Cat 6E cabling, and RG-6 twinax to all the rooms.

You're right, terminating twinax is a PITA.

 

[Albany Tom]

The only shortcut that winds me up is back feeding a circuit to power a panel from a generator. There's no excuse for that. If you don't have $200 or whatever for a cheap transfer switch, then just wire your furnace or whatever to be plugged into an outlet, and when the power goes out plug it into the generator. Not code compliant, but it isn't going to hurt anybody.

 

[Tango Golf Sierra]

If you can’t have 2 meters, call the power company and get your peak kw load in the past year. Figure your load calculation on your new building. Add the two loads together. If you can add that to your existing service panel without it overloading and have spare breakers, do it. If not you’ll need to upgrade your service to handle both. Run aluminum wire (if over 60ish amps) in conduit. Copper is out of the roof expensive. There is Cable in conduit that works well.

 

[flyingron]

Common sense also realizes that data cabling run into panelboard enclosures means someone with little or no training in working around live electrical parts could be injured or killed. A homeowner might feel qualified to do so, and that's why it's non-code compliant and dangerous. Electricity and surreptitious actions don't belong together.

It's also not permitted by the codes. Running data wiring near power lines is a far cry from using it in places where the electrical is terminated (panel boards). Data wiring insulation is often not sufficiently rated for the voltages present in such terminations and if even if it was it's dangerous to have terminations for low voltage stuff in places where regular power is present.

 

[Brad W]

there are some lockout mechanisms that allow it.... the breaker with the generator in-feed can not be switched ON unless the main incoming feel line is switched OFF

The only shortcut that winds me up is back feeding a circuit to power a panel from a generator. There's no excuse for that. If you don't have $200 or whatever for a cheap transfer switch, then just wire your furnace or whatever to be plugged into an outlet, and when the power goes out plug it into the generator. Not code compliant, but it isn't going to hurt anybody.

 

[3393RP]

It's also not permitted by the codes. Running data wiring near power lines is a far cry from using it in places where the electrical is terminated (panel boards). Data wiring insulation is often not sufficiently rated for the voltages present in such terminations and if even if it was it's dangerous to have terminations for low voltage stuff in places where regular power is present.

Agreed. See my post #55 above.

 

[Albany Tom]

there are some lockout mechanisms that allow it.... the breaker with the generator in-feed can not be switched ON unless the main incoming feel line is switched OFF

Yep, and that would provide the same protection as a transfer switch. I've seen solenoid or key switch lockouts, too, on mid sized panels in commercial applications. But bottom line, feeding a standard circuit backwards not ever the right answer.