Wire type for outbuilding

I asked before what size wire to run to my garage. Im almost ready to bring power to it. Now my question is what type of wire?
Its 120 foot run. Ill be using 2/0 aluminum w #2 ground in conduit. But what type of wire? Can I use a service entrance cable or should I run individual wires to meet code?
Thanks for your answers in advance.

When I last practiced direct burial rated UF or USE was available, I preferred Copper conductors .........Or one cold bury conduit and install individual THWN or THHN wires. If its 120/240 you would need to run FOUR conductors, 2 Hot UNgrounded L1 & L2,,,,,,1 Grounded Neutral,,,,,,1 Safety Equipment GroundiNG Conductor..

UF or USE direct buried cable in a trench or use conduit and individual conductors.

That was long ago, I cant say for sure what other choices there are today, see what any other choices current practicing electricians might suggest. You may get different preferences choices and reasons which to use, mine would be to use conduit filled with individual conductors, copper versus aluminum but aluminum is cheaper. If aluminum be sure to use proper anti oxidant !!!!!!!!!!!!!!!!!!!!!! and torque to proper values

When I practiced if you buried plastic conduit fine HOWEVER the riser that came up out of the earth for entrance into the building HAD TO BE RIGID

Of course if youre feeding a sub panel in an exterior building its Ground and Neutral Busses must be separate insulated and isolated from each other and each buildings electrical service requires proper grounding to a grounding electrode.

Its electrical so typically you will get plenty of answers lay as well as professional. Where fire and life safety are concerned and possibly insurance, you might want to consider consulting the NEC and any local authority where it applies.....

Your money your risk your choice, I suggest you do it SAFE, now see what other fine gents have to say and make YOUR decision.

John T Long retired n rusty EE so no warranty see what others may add to this

Cost dictates aluminum for me. But what I was wondering is service entrance cable acceptable in conduit? Cost less than the individual wires.
Conduit here requires 18 depth. Direct 24 depth. Extremely rock terrain so less depth is easier to deal with.

Cost dictates aluminum for me. But what I was wondering is service entrance cable acceptable in conduit? Cost less than the individual wires.
Conduit here requires 18 depth. Direct 24 depth. Extremely rock terrain so less depth is easier to deal with.

Insurance companies frown on aluminum wire.

Just sayin'.

(quoted from post at 18:50:03 07/17/23) Insurance companies frown on aluminum wire.

Just sayin'.

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Only downstream of the main breaker branch circuits.

Even then, no if current connection practices are followed for large capacity circuits such as to an out building feed or the stove, oven, water heater, etc.

This post was edited by DoubleO7 on 07/17/2023 at 03:07 pm.

i have a run of 6 gauge UF in conduit buried to my garage. the run is within a couple of feet of yours. all of my major current draws are in the machine shed, so the cable to the garage doesn't work too hard. it has been in place for 30+ years and has neither melted itself nor set the ground on fire yet

ps disclaimer: this is neither an endorsement nor a recommendation, simply an observation O

This post was edited by HFJ on 07/17/2023 at 03:17 pm.

But what I was wondering is service entrance cable acceptable in conduit?

Sorry, to that specific question I DONT KNOW My NEC is very outdated. The answer and difference would relate to HEAT DISSIPATION of x number of individual wires versus a piece of USE, but as USE is rated for direct burial anyway and isnt jacketed like UF, my best pure guess is SUBJECT TO SIZE OF CONDUIT its okay BUT DO NOT TAKE MY GUESS FOR IT

John T

I am not an electrician. You need to use the right SE cable type underground (USE) even in a conduit. You might need more than a 2/0 cable if you are running 100 amps 120 feet.
Ampacity for long runs


This link has the details you need and is too much to repeat here:
Can You Run Service Entrance Cable In Conduit? (Explained)
It says that if you are running service entrance cable, you can only use USE, not SE underground.
It also says you can use USE inside a conduit.

I am not an electrician. You need to use the right SE cable type underground (USE) even in a conduit. You might need more than a 2/0 cable if you are running 100 amps 120 feet.
Ampacity for long runs

This link has most of the details you need and is too much to repeat here:
Can You Run Service Entrance Cable In Conduit? (Explained)
It says that if you are running service entrance cable, you can only use USE, not SE underground.
It also says you can use USE inside a conduit.

How much amperage do you need in your garage? You would probably need a gauge heavier for 120' but #2 is a lot.

The ground (green or bare) and neutral (white) need to be separate in a sub panel. Also you should not connect the neutral to a ground rod in the sun panel

The only place where the ground, neutral and ground rod are connected together is in the main panel.

I talked to an inspector this morning and they said 2/0 was sufficient. But I keep seeing conflicting info on using service entrance cable. And I didnt ask that question. The price has dropped on the wire lately. Its about $350 for the cable and $400 for individual wires.

If you are going to run aluminum, get an electrician to help you. Aluminum works just fine, as long as you get five or six things perfect (copper is bullet proof, and much more forgiving of installation errors). First, make sure you get a good electrical grade of aluminum. Next, don't apply too much tension pulling it. You already mentioned running it in conduit, and make sure the conduit is burred about 30 inches, so anything driving over it doesn't crush the conduit. Next make sure to use the right compound on the wire at terminations. Also make sure the terminals are listed for aluminum and make sure you torque the terminations properly. Finally, retorque the terminations annually. Do all of this and the aluminum will work fine.

All of the entrance cable and underground direct burial I have seen is twisted together.
If a problem with one leg/conductor should happen, you will have to pull all at once.

With individuals, not tall twisted together, you might be able to just pull the bad one and replace it.

If either are in conduit.

Check the code requirements for your area, they allow service entrance underground through pvc conduit in my area
That s what I ran from service pole to my house and service pile to my shop

SE cable wouldn't pull through conduit very easily. I would just use aluminum urd - three conductors plus a ground

X2 DITTO, that's right and we agree yayyyyyyyyyyy

In our jurisdiction when I practiced (may be different now) the NG Bond was at the first means of disconnect which was usually and typically the main service entrance panel

John T

Just sayin' but if a $50 one-time expense is going to break you, maybe you should hold off on the project.