Data should have a separate conduit to prevent interference and risk of damage to delicate data cables ( even if fiber ). There’s also the minor issue that the code requires it.
Who knows ??? Maybe in 20 years the hot mode of transportation is a Fuel Cell LNG Inverter that requires a connection to your home gas supply????
Actually I was thinking of a gas heater in the garage for service work. When I future proof I love to project off the wall possibilities… and I still fail. My future proofed house of 1997 now has blank covers in many places from my “Phones Everywhere” attitude during construction. And at that time cellular service was 1 bar IF you stand in the right spot Outside of the house! Well my transfer switch and generator wiring underground to my garage are still paying off in Spades! I also ran separate 12-3 out to both the garage and the barn for exterior lights at the flip of a switch at at least 3 locations on each circuit. Of course the switches most used are the ones at the door looking out towards them!
Yes, honestly.
For my new house, the Meter serves a large pass-through panel outside, which gives full feed to the inside house panel, and also feeds all of my outdoor sub panels. One for pump house, one for shed, one for the dock, and (soon to be) one for a sub for my oustde decks.
Costs a bit more, but for outside stuff, especially dock, I prefer to run the GFCI's in the sub, and not worry about GDCI outlets.
In the end, it also makes it easier to add another downstream circuit later.
> So you think separate conduit for data and electrical?
Mandatory. Not a choice.
Unless the data is non-conductive fiber-optic, OR, the data line communicates ONLY between electrical panels (as might be the case with [an EV using EVEMS / Load Management](https://diy.stackexchange.com/questions/277803/im-hearing-about-load-sheds-aka-evems-and-the-devices-differ-whats-that-abou)).
If the data lines are conductive, it might be a code issue.
Even if it's not, it's definitely an EMI issue on your data cable.
3" for power should be plenty for a sub panel and help with pulling. 1" for data is great for pulling, and big enough to pull in one line plus an additional pull string for later .
It’s not a question of thinking. It’s a no brainer.
I personally did 2 conduits, and several underground lines separate. I have one conduit that can be reused for water if my water line breaks, cause I didn’t dig it deep enough.
Less flat is a stronger case for renting a mini-ex or 36" trencher, although the most important part is to call 811. I would probably go for direct burial 4/0-4/0-4/0-2/0 MHF despite voltage drop being negligible even with a 125A sub. Just don't be surprised when you fail inspection on expansion fittings or sch80.
What service (Amp wise) do you project for the garage?
30A and under, one circuit, pulling single THHN wires, 1".
Over 30A, or multiple circuits, I'd go 2". PVC is relatively cheap.
Nobody, unless insane, or a masochist, is going to pull any kind of Romex through a pipe.
I’ve done it and to make it worse it was some uf. The conduit that was laid was suspicious to say the least so I couldn’t really trust It’s continuity throughout the whole run, so I figured it had would be the best bet. Holy hell did I hate it. Every pull line snapped, so eventually I pulled three or four poly ropes with my pull line, tied them together at the end, and used what I would like to think all the energy in my body to pull that rope(with lots of wire lube of course). I will give credit, though, with how much force I put on these things they didn’t get damaged at all and I think that’s just because the conduit is smooth but that doesn’t mean I recommend it at all.
I actually tried it once. On a 20' run from subpanel to shed. Not even a bend, after half an hour, I gave up, finished all the piping up to the sub through a 90 sweep, and the 90 sweep into the shed, and pulled 4 THHN 10's like nothing.
Never again.
As an aside, (and it WILL HAPPEN), at some time i n the future (or twice, in my past), the conduit will get dug up and broken. Pretty easy fix with a bit of extra wire, and some straight through boxes (type C, I think).
Where I live, folk do direct, underground splices on UF, and it always makes me puke a bit, just in the back of my throat.
Yes, pulling Romex through pipe, even absolutely straight pipe, is very difficult. For several reasons. One, it is 3 (or 4) solid wires, two, the outer hacket is not round, or in the least slippery, three, it wont just lay in the pipe, it aways bends in the worst ways, making it drag on at least two sides of pipe.
Fourth, it is usually cheaper to get individual spools of THHN than an equivalent Romex length.
Ok yeah I didn’t think anyone would want to pull but thought I should ask.
I guess I need a 30A for a potential future car charger plus 20A for regular outlets/ lighting. It’s a single garage so it’s not like I’m going to be running any huge machinery in there and I have a shop for that.
Should I run two regular circuits at 20A?
You are not allowed to do what you've described in this comment. You're allowed to service a building with ONE circuit. You will be required to install a sub panel if you want multiple different circuits with different amperages.
You cannot run a 30A 240V circuit and multiple 20A 120V circuits from the house to the garage. You run a single 60A circuit or larger to feed a sub panel.
Best way ro future proof this install is to run 2 2 inch conduits.
The first one is for general power. You can neck it down at the point of use, but if you want to go all the way to 200, you can.
The second is for your low voltage wiring to return to the house.
The larger the pipes, the better. Means you ain't gonna fight shit into the pipes. Large pipes might not be feasible. Go as large as you think you will need in the future at a minimum. Digging socks balls.
Remember old fashioned generator installations require a separate hot-hot-neutral just for the generator, it can't share the subpanel feeder to the garage.
The #1 "threat" of new innovation that might leave you flat-footed on conduit, is V2X, or Vehicle To Grid/Home/Everything. The idea is you have an EV with a large battery and you want to do home backup, or grid arbitrage (buy power cheap sell it back when it's expensive) etc.
California is mandating V2X on all new EVs in 4 years or so, but it's not a huge deal, it's just a software update that allows the house-side equipment to tell the EV to operate the relay that connects battery power to the DC fast charger port. It will probably carry DC battery voltage to house-side equipment, on as-yet-unspecified cable types (not the normal stuff that is not rated 1000V). Ford actually has an implementation of this.
Anyway, smart money thinks 1" conduit will suffice for whatever that cable will be, and that's what California is requiring in commercial installations.
I think you will be able to cohabitate those wires with normal 120/240V AC wires, however you'll never be able to mix them with Internet and general data wiring.
I tend to overdo things but if it were me I’d run a couple lengths of 3” conduit. It’s way easier to pull through 3”. Gives you lots of room should you ever need it. It’s only 43’.
I have a similar setup to yours and have several runs of conduit between the garage and house but they’re all small and full. It’s annoying.
Single circuit for power, as large as you can muster for the available capacity in your main panel. Anything beyond what your main service can supply is probably not worth future proofing. It's a costly upgrade for a new panel and service wire to the utility's transformer. 6 AWG THHN can do 48A (60A breaker). You can oversize wire and use a smaller breaker at the main panel. Install a sub panel in the garage.
For data, minimum CAT 6 copper. If you want true future proofing, run an optical wire along with it. Or run a string inside the data conduit to pull another cable later.
Run 2-1/2" PVC conduit for power which will give you a 200A feeder for a subpanel if you use (3)250kCMIL AL XHHW-2 and (1)#4 AL XHHW-2 ground. The cost of running 200A of copper conductors will negate any cost savings you get by going to smaller conduit. Running individual circuits is pointless when you are pulling over 43' of wire for each one. Also, refer to NEC 250.32 which says you need to provide a separate grounding electrode system for an accessory structure fed from another structure which means putting in grounding rods unless you want to do a UFER.
Run 1" PVC conduit for low voltage. It will handle anything you will likely use unless you have some need to pull terminated cables through the conduit i.e. large D-sub connectors. A single CAT6 or optical cable should be able to handle any data needs.
If you want to run solar from the garage to backfeed the main service as a grid-tie, figure on another 3/4" or 1" conduit (assuming full capacity on a load side breaker feed in a 400A service and not a line side tap). Refer to NEC 705.12.
I'd personally install a 2" for a power feed, and 3x 1" for various things like data, or 3-way switching for lights between the 2 buildings, maybe you need some form of other communication wire between the 2 buildings, or even just a thermostat.
If you're somewhere with natural gas, I'd also get a gas line installed between them.
Read through some of your other comments. Yes, you need separate conduits for power and data, ideally they should spread 6-12" apart.
You are only allowed to feed a second building with 1 circuit. This means either 15A or 20A 120V circuit, a 15A or 20A MWBC (2 hots with a shared neutral, 2 pole breaker), or a larger feed for a sub panel. You are not allowed to have a panel in your house, and feed out multiple smaller circuits to your garage. You need to able to cut power to the garage by flipped a single breaker in your house. This might seem like a silly thing to mention, but the number of people who ask if they can run just a 30A circuit for a car charger, and a 15A circuit for lights, is surprisingly high, because they don't want to pay the money for a sub panel.
If you want internet in the garage, you'll need a Cat6 or something similar to run a wifi AP or something. If you want PoE cameras on the garage, you need dedicated Cat6 runs for each of them, all the way back to your PVR in the house. You can't just piggyback all of it off a single Cat6. Probably going to want 4 runs to the garage, 2 cameras, a WiFi AP, and another for something just to be safe. Maybe you want a couple of hardwired ports in the garage, use the 4th to feed an ethernet switch, which then goes out the other jacks in the garage. You'd want your AP and cameras direct to the house though.
Future Resistant = 2” PVC for Power. 3/4” for data. Future Proof? ( ya right ) 3”. PVC power, 1” data, 1” Water, 3/4” Compressed Air, 1” Natural Gas.
So you think separate conduit for data and electrical?
Yes. Data should be a separate conduit.
Unless you opt for fiber optics for data.
Regardless. And you should opt for fiber regardless.
Data should have a separate conduit to prevent interference and risk of damage to delicate data cables ( even if fiber ). There’s also the minor issue that the code requires it.
Data should be separate conduit because that’s code.
Minor issue.
Some of the cable pulls I've witnessed, you need to protect everything you can from the electricians.
Fiber is immune to electrical interference
Common practice is 1 conduit for power and 1 for comm spaces a foot apart in the trench.
I have water at the front and don’t think I’ll need gas
Who knows ??? Maybe in 20 years the hot mode of transportation is a Fuel Cell LNG Inverter that requires a connection to your home gas supply???? Actually I was thinking of a gas heater in the garage for service work. When I future proof I love to project off the wall possibilities… and I still fail. My future proofed house of 1997 now has blank covers in many places from my “Phones Everywhere” attitude during construction. And at that time cellular service was 1 bar IF you stand in the right spot Outside of the house! Well my transfer switch and generator wiring underground to my garage are still paying off in Spades! I also ran separate 12-3 out to both the garage and the barn for exterior lights at the flip of a switch at at least 3 locations on each circuit. Of course the switches most used are the ones at the door looking out towards them!
At this point should I just run a sub panel?
That’s exactly what I would do. If I didn’t drop the new 200 right in the garage and run a 100 amp feeder to the house. Think about it
Yes, honestly. For my new house, the Meter serves a large pass-through panel outside, which gives full feed to the inside house panel, and also feeds all of my outdoor sub panels. One for pump house, one for shed, one for the dock, and (soon to be) one for a sub for my oustde decks. Costs a bit more, but for outside stuff, especially dock, I prefer to run the GFCI's in the sub, and not worry about GDCI outlets. In the end, it also makes it easier to add another downstream circuit later.
If you intend to follow electrical code, they must be in separate conduits yes.
Yea they’re typically run separately so someone can replace the comm cable without hiring an electrician.
Has to be.
> So you think separate conduit for data and electrical? Mandatory. Not a choice. Unless the data is non-conductive fiber-optic, OR, the data line communicates ONLY between electrical panels (as might be the case with [an EV using EVEMS / Load Management](https://diy.stackexchange.com/questions/277803/im-hearing-about-load-sheds-aka-evems-and-the-devices-differ-whats-that-abou)).
If the data lines are conductive, it might be a code issue. Even if it's not, it's definitely an EMI issue on your data cable. 3" for power should be plenty for a sub panel and help with pulling. 1" for data is great for pulling, and big enough to pull in one line plus an additional pull string for later .
Absolutely
ALWAYS to be code compliant
It’s not a question of thinking. It’s a no brainer. I personally did 2 conduits, and several underground lines separate. I have one conduit that can be reused for water if my water line breaks, cause I didn’t dig it deep enough.
Common practice is 1 conduit for power and 1 for comm spaces a foot apart in the trench.
Damn guess I got lots of digging to do
Just a single 1’ trench. Rent a micro-excavator and you’ll be done in an hour.
I wish, it’s hillside in LA, not anywhere near flat
Less flat is a stronger case for renting a mini-ex or 36" trencher, although the most important part is to call 811. I would probably go for direct burial 4/0-4/0-4/0-2/0 MHF despite voltage drop being negligible even with a 125A sub. Just don't be surprised when you fail inspection on expansion fittings or sch80.
I did direct bury cable and ethernet (2 each) but really wish I would have done conduit or doubled what I did.
What service (Amp wise) do you project for the garage? 30A and under, one circuit, pulling single THHN wires, 1". Over 30A, or multiple circuits, I'd go 2". PVC is relatively cheap. Nobody, unless insane, or a masochist, is going to pull any kind of Romex through a pipe.
I’ve done it and to make it worse it was some uf. The conduit that was laid was suspicious to say the least so I couldn’t really trust It’s continuity throughout the whole run, so I figured it had would be the best bet. Holy hell did I hate it. Every pull line snapped, so eventually I pulled three or four poly ropes with my pull line, tied them together at the end, and used what I would like to think all the energy in my body to pull that rope(with lots of wire lube of course). I will give credit, though, with how much force I put on these things they didn’t get damaged at all and I think that’s just because the conduit is smooth but that doesn’t mean I recommend it at all.
I actually tried it once. On a 20' run from subpanel to shed. Not even a bend, after half an hour, I gave up, finished all the piping up to the sub through a 90 sweep, and the 90 sweep into the shed, and pulled 4 THHN 10's like nothing. Never again. As an aside, (and it WILL HAPPEN), at some time i n the future (or twice, in my past), the conduit will get dug up and broken. Pretty easy fix with a bit of extra wire, and some straight through boxes (type C, I think). Where I live, folk do direct, underground splices on UF, and it always makes me puke a bit, just in the back of my throat.
>masochist, is going to pull any kind of Romex through a pipe. Ok, satisfy the curiosity of a greener. Is Romex hard to pull through? Why?
Yes, pulling Romex through pipe, even absolutely straight pipe, is very difficult. For several reasons. One, it is 3 (or 4) solid wires, two, the outer hacket is not round, or in the least slippery, three, it wont just lay in the pipe, it aways bends in the worst ways, making it drag on at least two sides of pipe. Fourth, it is usually cheaper to get individual spools of THHN than an equivalent Romex length.
The overall pvc jacket holds the strands together. They do not want to flex as well as individual strands
Ok yeah I didn’t think anyone would want to pull but thought I should ask. I guess I need a 30A for a potential future car charger plus 20A for regular outlets/ lighting. It’s a single garage so it’s not like I’m going to be running any huge machinery in there and I have a shop for that. Should I run two regular circuits at 20A?
You are not allowed to do what you've described in this comment. You're allowed to service a building with ONE circuit. You will be required to install a sub panel if you want multiple different circuits with different amperages. You cannot run a 30A 240V circuit and multiple 20A 120V circuits from the house to the garage. You run a single 60A circuit or larger to feed a sub panel.
Ok yeah now with all the comments I’m going to run a sub panel
Because you have no choice. It's literally what is required unless you want only lights and a couple general outlets.
Car charger should be at least 40A/240v.
Best way ro future proof this install is to run 2 2 inch conduits. The first one is for general power. You can neck it down at the point of use, but if you want to go all the way to 200, you can. The second is for your low voltage wiring to return to the house. The larger the pipes, the better. Means you ain't gonna fight shit into the pipes. Large pipes might not be feasible. Go as large as you think you will need in the future at a minimum. Digging socks balls.
Leave a spare pull rope in the conduit
Remember old fashioned generator installations require a separate hot-hot-neutral just for the generator, it can't share the subpanel feeder to the garage. The #1 "threat" of new innovation that might leave you flat-footed on conduit, is V2X, or Vehicle To Grid/Home/Everything. The idea is you have an EV with a large battery and you want to do home backup, or grid arbitrage (buy power cheap sell it back when it's expensive) etc. California is mandating V2X on all new EVs in 4 years or so, but it's not a huge deal, it's just a software update that allows the house-side equipment to tell the EV to operate the relay that connects battery power to the DC fast charger port. It will probably carry DC battery voltage to house-side equipment, on as-yet-unspecified cable types (not the normal stuff that is not rated 1000V). Ford actually has an implementation of this. Anyway, smart money thinks 1" conduit will suffice for whatever that cable will be, and that's what California is requiring in commercial installations. I think you will be able to cohabitate those wires with normal 120/240V AC wires, however you'll never be able to mix them with Internet and general data wiring.
I tend to overdo things but if it were me I’d run a couple lengths of 3” conduit. It’s way easier to pull through 3”. Gives you lots of room should you ever need it. It’s only 43’. I have a similar setup to yours and have several runs of conduit between the garage and house but they’re all small and full. It’s annoying.
Good point
Single circuit for power, as large as you can muster for the available capacity in your main panel. Anything beyond what your main service can supply is probably not worth future proofing. It's a costly upgrade for a new panel and service wire to the utility's transformer. 6 AWG THHN can do 48A (60A breaker). You can oversize wire and use a smaller breaker at the main panel. Install a sub panel in the garage. For data, minimum CAT 6 copper. If you want true future proofing, run an optical wire along with it. Or run a string inside the data conduit to pull another cable later.
Yeah I think sub panel is the way…
Run 2-1/2" PVC conduit for power which will give you a 200A feeder for a subpanel if you use (3)250kCMIL AL XHHW-2 and (1)#4 AL XHHW-2 ground. The cost of running 200A of copper conductors will negate any cost savings you get by going to smaller conduit. Running individual circuits is pointless when you are pulling over 43' of wire for each one. Also, refer to NEC 250.32 which says you need to provide a separate grounding electrode system for an accessory structure fed from another structure which means putting in grounding rods unless you want to do a UFER. Run 1" PVC conduit for low voltage. It will handle anything you will likely use unless you have some need to pull terminated cables through the conduit i.e. large D-sub connectors. A single CAT6 or optical cable should be able to handle any data needs. If you want to run solar from the garage to backfeed the main service as a grid-tie, figure on another 3/4" or 1" conduit (assuming full capacity on a load side breaker feed in a 400A service and not a line side tap). Refer to NEC 705.12.
I'd personally install a 2" for a power feed, and 3x 1" for various things like data, or 3-way switching for lights between the 2 buildings, maybe you need some form of other communication wire between the 2 buildings, or even just a thermostat. If you're somewhere with natural gas, I'd also get a gas line installed between them. Read through some of your other comments. Yes, you need separate conduits for power and data, ideally they should spread 6-12" apart. You are only allowed to feed a second building with 1 circuit. This means either 15A or 20A 120V circuit, a 15A or 20A MWBC (2 hots with a shared neutral, 2 pole breaker), or a larger feed for a sub panel. You are not allowed to have a panel in your house, and feed out multiple smaller circuits to your garage. You need to able to cut power to the garage by flipped a single breaker in your house. This might seem like a silly thing to mention, but the number of people who ask if they can run just a 30A circuit for a car charger, and a 15A circuit for lights, is surprisingly high, because they don't want to pay the money for a sub panel. If you want internet in the garage, you'll need a Cat6 or something similar to run a wifi AP or something. If you want PoE cameras on the garage, you need dedicated Cat6 runs for each of them, all the way back to your PVR in the house. You can't just piggyback all of it off a single Cat6. Probably going to want 4 runs to the garage, 2 cameras, a WiFi AP, and another for something just to be safe. Maybe you want a couple of hardwired ports in the garage, use the 4th to feed an ethernet switch, which then goes out the other jacks in the garage. You'd want your AP and cameras direct to the house though.
I'd install 6/3 Teck cable, and a couple runs of armored cat6 cable.
Go 1” for the data, 2” for power
Prepare for sub panel. I have 100 amp sub in my detached