Detached garage power questions

[onlyn8v]

I am running 70' to my detached garage.

I think Im going to run 100 amp to be safe. I trenched 2" sch. 40 30" down (planning for driveway on top)

I can't find NEC regs on a couple things,

What is the height that the power should come into the structure?

I have these to leave the house and to go into the garage. Is there anything better, or are these good?

https://www.homedepot.com/p/Cantex-...ERCH=REC-_-pipsem-_-202043388-_-202043420-_-N

 

[u2slow]

Its handy if you can come up the wall high enough to come straight through into the back of the panel.

 

[teamextreme]

Those LB's are what you would use. No code on height requirements, but as u2slow said, it's a clean install to go in the back of the panel. But that means you have to run conduit up the wall fairly high and might be considered unsightly. Alternative is to use back to back LB's., one on outside, one on inside.

 

[onlyn8v]

I like that idea, then sch 40 up to the panel inside. Might look better looking.

 

[Jazz1]

Dig a trench. I buried mine power to garage. 60 amp is plenty.

 

[onlyn8v]

Yes, 30" deep trench, 2" conduit.

 

[u3b3rg33k]

Dig a trench. I buried mine power to garage. 60 amp is plenty.

I did 200A. 60A won't run my compressor, plasma cutter, and heater at the same time.

Yes, 30" deep trench, 2" conduit.

I'd drop in a 2nd 2" conduit for "future" use - the trench is the hard part. maybe you'll want to upgrade the power, or run data, or pull some pex through for heat. plenty of options with a 2" spare.

 

[onlyn8v]

I did 200A. 60A won't run my compressor, plasma cutter, and heater at the same time.



I'd drop in a 2nd 2" conduit for "future" use - the trench is the hard part. maybe you'll want to upgrade the power, or run data, or pull some pex through for heat. plenty of options with a 2" spare.

I wasnt going to, but literally everyone (including on here) told me to run another. That one is going to be 1.25

Also, This is a 24x30 shop with Mig, TIG, air compressor, lift and mini split unit. I think 100amps is the best bet for me.

 

[tros]

I did 200 amp 42 breakers .Dug 4 feet down in 2 inch pipe 1.5 inch to run cable and inter net to the garage .

 

[48windsor]

here is a question might help others too.
So 60 amps is enough as mentioned earlier.
How many space sub panel is sufficient?

 

[Jazz1]

here is a question might help others too.
So 60 amps is enough as mentioned earlier.
How many space sub panel is sufficient?

That’s my 60 amp panel for 24x30 garage I have 3 220 outlets in garage never tripped a breaker. No electric heat

 

[onlyn8v]

So I dropped in 2" and a 1.5" for a backup. Now, im waiting for temps to stay out of freezing long enough to finish it out.

 

[75gmck25]

Upsizing the subpanel is cheap, so I went with a 100 amp 24 space panel. I may never need that many breakers, but the additional cost was probably $25 more than a smaller panel. The subpanel main breaker does not have to match your wire's max amperage, since the breaker in the main panel is what determines max amperage into the line.

I have a 60 amp breaker in the main panel, feeding the 2-2-2-4 AL to 100 amp subpanel, since 90 amp breaker (max for the wiring) was a special order item. I also used a QO panel to match my main panel so I could reuse some breakers I had left over.

Bruce

 

[u2slow]

since 90 amp breaker (max for the wiring) was a special order item.

I often get breakers online (including amazon). Considerable savings over retail big-box, or wholesaler.

 

[Norcal]

here is a question might help others too.
So 60 amps is enough as mentioned earlier.
How many space sub panel is sufficient?

Can never have too much but can have too few, 24 space or more would be good but avoid using a Zinsco II panel, (Eaton BR*) like in post number 11, worst panel on the market.


*Originally was Bryant BR, then Westinghouse BR, then Cutler-Hammer BR, now Eaton, Eaton CH, is top of the line.

 

[sberry]

I am a fan of number 2 and the box stores havnt caught on to this yet to have 90 on the shelf. I have seen some 70 floating around, bought a couple on sale at one. I use a 60 and willing to trade up if needed, never had it happen. Agree in this case of 75 ft, would use 2 and a 90.
It will tolerate a quite a bit instant overload. Bit different for a home hobby or someone going to max the tools out and working every day. 375 cutter or bigger? 5 hp comp is about 23 run today. How much is a heater?

 

[onlyn8v]

Silly question, but I think I have to ground within 6' of meter. If Im pulling 2-2-2-4 do I slit the casing of the main wire sheathing in the conduit to break out the grounding wire? Or is it a separate ground wire from panel to grounding rod?

 

[pattenp]

The ground rod wire is a separate wire.
The 2-2-2-4 wire you are pulling, if this is the wire in conduit underground it should not have an outer sheath. Please clarify what wire you are asking about splitting the sheath on.

 

[onlyn8v]

Im thinking I should be using USE wire because im in conduit. Am I correct in assuming I need USE wire and URD as I am underground in conduit?

 

[pattenp]

SER is not allowed to be installed underground in conduit. Sorry if I'm misunderstanding where you plan on using the SER cable.

 

[pattenp]

If the wire is entering the structure you are not to use URD because it has no fire rating. You should use individual conductors of xhhw-2 or Mobile Home Feeder which is rhh/rhw/use. The USE rating is not necessary with wire being in conduit. USE is direct bury.

 

[onlyn8v]

I actually updated the post.

Im thinking I should be using USE wire because im in conduit. Am I correct in assuming I need USE wire, and it is olny available is single conductor wires?

 

[wyliesdiesels]

Silly question, but I think I have to ground within 6' of meter. If Im pulling 2-2-2-4 do I slit the casing of the main wire sheathing in the conduit to break out the grounding wire? Or is it a separate ground wire from panel to grounding rod?

The wire for the ground rods is different than the equipment grounding conductor wire in the feeder.

Dont confuse the 2.

Checkout the electrical FAQs sticky and look at the diagrams for 4-wire feeder to give you a better understanding of what you need to do.

Also, wire with an outer sheathing such as SEU or SER is not permitted for use underground so dont use that.

I actually updated the post.

Im thinking I should be using USE wire because im in conduit. Am I correct in assuming I need USE wire, and it is olny available is single conductor wires?

Dont bother with USE.

Get some MHF- mobile home feeder. Needs to be in conduit indoors. If thats a problem, switch to SER in a junction box above ground.

 

[onlyn8v]

I will do that, Thank you for all help guys!

 

[onlyn8v]

Hi guys, Im having a problem getting the MHW in my area. They have 2,2,2,4 SER, but I don't know much about it. Im not even sure if I can get it through a 90 bend in my 2" conduit.
What do you guys think? Should I try the SER or run individual conductors?

 

[pattenp]

If you have conduit in ground use XHHW-2 in single conductors in the size you need. . You don't need MHF. SER is not allowed underground in conduit.

 

[onlyn8v]

can XHHW-2 be run in wall bays without conduit? I have to go in the bay next to the panel in my home.

 

[Innovate1]

Big wire is hard to get through standard bends. I used 24" radius bends for my underground runs. You can get XHHW-w from wireandcableyourway.com - that's what I did. Just tell them how much you want on each spool and you have each conductor on individual spools ready to feed. It will pull easier than MHF as there are no twists. Usually you can drop at least one size for the neutral but check with AHJ to be sure it is allowed.

 

[Innovate1]

can XHHW-2 be run in wall bays without conduit? I have to go in the bay next to the panel in my home.

No. Individual conductors and must be in conduit. Use some bends or use a box to convert to another type wire that doesn't need conduit. I used a combination of 90 bend and LB to avoid splicing wire. On a short section with only 1 bend a standard bend is ok even with big wire.

 

[onlyn8v]

In the conduit run, Can I run ground with no insulation? Or should I just use insulated

 

[pattenp]

If the ground is copper it can be uninsulated. If using aluminum it needs to be insulated. My suggestion is using insulated with copper. The XHHW-2 I suggested would be in aluminum.