Finally Running A Sub Box To The Garage. What Do I Need

[jonp]

This subject has been covered several times but I want to get it right. Got a portable stick welder and a plasma cutter. AC/DC both 50 Amp dc and 40 AC.

Main 200 amp box on outside of house, 100 amp sub in the house so i have 100 amps to play with.

100 ft to garage, line will be underground. Using left over to wire garage but no heavy duty machinery. Small air compressor, hand tools, lead melter etc. Table saw, homeowner stuff

What do i need for line, sub box etc. With the cost of line now i want to get this right the first time

What do I need?

[HATCH]

100 amp breaker for main panel
100+ feet of Southwire 2-2-2-4 Black Stranded Al MHF Use-2 Cable
100 feet of 2 inch grey conduit (electrical) with assorted fittings to make connections to house panel and get into garage
1 x Square D Homeline 100-Amp 12-Spaces 24-Circuit Main Breaker Plug-On Neutral Load Center
assorted square d breakers

All is available from Lowes

That is your cheapest route.
Run the wire in conduit that is buried 24 inches deep (by code)
Inside the garage your gonna want to run 14-2 romex (15 amp outlets) or 12-2 romex (20 amp outlets)
Then whatever you devices is your gonna need to get the correct rated breaker and run the correct size wire.

Your not gonna be able to run the same size wire from the main panel to the garage on your devices in the garage as its way to big.

[jonp]

Thanks Hatch. I still have most of a roll of 12/2 from wiring the house. Ill use that for the outlets in the garage. The cutter calls for 50amp so i think i will go 60 to be sure. What wire from box to dc outlet.

[country gent]

Remember to add in accessories IE does the plasma cutter require air pressure to use? if so cutter, lights and air compressor.

[jonp]

Remember to add in accessories IE does the plasma cutter require air pressure to use? if so cutter, lights and air compressor.

Yes, a small air compressor that will run off 15amps as I'm doing now with no problem.

[redneck1]

I am right in the middle of wiring up my two car garage shop .
For the first time ever I have a full 200 amps to play with .

For my air compressor and welder I wired up for possible future upgrades , heavier wire and outlets....
But I don't go big on the breakers , if my welder or compressor says it needs a 30 amp circuit I use a 30 amp breaker .
My reasoning is if something goes wrong I don't want whatever is plugged in to be able to pull more amperage then it's rated for .

If I ever need to run something bigger it's just a matter of plugging in a
properly sized breaker .up to whatever my wire and outlets are rated for .

[HATCH]

You need to remember that whatever sized breaker you have you must have everything between that breaker and whatever your powering rated for that breaker.

So don’t use a 20 amp breaker when your running 16-2 romex because one day it’s gonna burn your shop down.
Wire when ran close to the limit will get warm. Wire run over its limit will get hot. So hot that it can catch on fire.

For your 50 amp device, I would use 6 gauge.
I would rather run a bigger diameter wire then needed then take a chance. You could get away with 8ga.

Please keep in mind that with the exception of the run from the house to the shop all the wire you should be running is copper.

Aluminum service wire is pretty common. Keep in mind that you run a size bigger then you would of copper but copper is expensive

[jonp]

Hatch, what is the difference between URD and MHF? They look the same but it says URD cant be installed inside. Does URD go from an outside box to another one outside while MHF can go to an inside box?

[Handloader109]

Udr is an underground feeder wire, can be directly buried. Use for your line between the panels. The MHF is a mobile home feeder. I don't think I'd use it anywhere you are looking at.

Sent from my SM-G892A using Tapatalk

[jimlj]

I'm not trying to be a jerk, but if you are asking how to wire a garage on a bullet casting forum perhaps you should consult with an electrician? I was an electrician for over 40 years, and it got to where I refused to tell anyone how to do electrical work because if they did it wrong, I would be blamed for their mistakes. I am now happily unemployed, on permanent vacation. It makes absolutely no difference to me if someone does their own wiring financially, but I am still concerned with their safety. There are people here who are knowledgeable on the subject, and there are several more who are not. Judging from past similar questions, all are happy to post their suggestions.

[Alan in Vermont]

What wire from box to dc outlet.

Where are you coming up with a need for a DC outlet?

I've never seen any homeowner/ light commercial welders that require DC current input. Usually if they are designated AC/DC that is their OUTPUT capability. The AC/DC Lincoln "buzzbox" 225
AC/DC is that way as is the larger 250amp(output)with the rounded top on the cabinet. Those both run 14 VAC input

[Lloyd Smale]

well you do need a 100 amp Pannel. But id look at the local codes for wire size conduit burial depts ect.

[Lloyd Smale]

I'm not trying to be a jerk, but if you are asking how to wire a garage on a bullet casting forum perhaps you should consult with an electrician? I was an electrician for over 40 years, and it got to where I refused to tell anyone how to do electrical work because if they did it wrong, I would be blamed for their mistakes. I am now happily unemployed, on permanent vacation. It makes absolutely no difference to me if someone does their own wiring financially, but I am still concerned with their safety. There are people here who are knowledgeable on the subject, and there are several more who are not. Judging from past similar questions, all are happy to post their suggestions.

I agree. Worked as a lineman all my life but even that doesnt make me an expert interior electirician. Would you go to an electrical site and ask someone there what the best alloy for bison is??

[Randy Bohannon]

When I rewired my house I hired an electrician who evaluated what I wanted/ needed . He directed to wire size and other considerations . I mounted all of the boxes and pulled all the wires, electricians did all the switch wiring and tie in’s to the panel,it is 100% to code now and a pleasure to use. I had 60’ to my garage and did 10-2 in 2” conduit runs my lead pots just fine.

[Mal Paso]

I would put in conduit box to box and pull in regular copper THHN. The new stuff is slick as snot and pulls in easy. Aluminum wire needs to have it's lugs checked every so often as they loosen over time.

[jonp]

I'm not trying to be a jerk, but if you are asking how to wire a garage on a bullet casting forum perhaps you should consult with an electrician? I was an electrician for over 40 years, and it got to where I refused to tell anyone how to do electrical work because if they did it wrong, I would be blamed for their mistakes. I am now happily unemployed, on permanent vacation. It makes absolutely no difference to me if someone does their own wiring financially, but I am still concerned with their safety. There are people here who are knowledgeable on the subject, and there are several more who are not. Judging from past similar questions, all are happy to post their suggestions.

Because this question has been addressed on this forum before and there are a number of residential/industrial/commercial electricians on here. I can look at the answers and look up if they make sense or are not code. If someone chimed in to run 10/3 off a 100 amp breaker i'd throw the flag. 2-2-2-4 AI MHF will handle the job

As for code, im outside of a zoned local code place so reley on National Code which I can read. I know about depth to bury, figuring out conduit size, voltage drop over distance etc. I'm asking the opinions of people that do this for a living as to what they would use for the job to compare to what i've written down. For example, you can use copper or aluminum feeder. I was going with aluminum as cheaper but wanted to see what others thought. There are a few types of AL that would do the job, MHF was brought up by Hatch.

If you dont want to answer thats fine.

[jonp]

Where are you coming up with a need for a DC outlet?

I've never seen any homeowner/ light commercial welders that require DC current input. Usually if they are designated AC/DC that is their OUTPUT capability. The AC/DC Lincoln "buzzbox" 225
AC/DC is that way as is the larger 250amp(output)with the rounded top on the cabinet. Those both run 14 VAC input

The wifes parents monster RV takes 50 amps so I figured to kill 2 birds with one stone on the 50amp recepticle. Going to run a couple of 15 amp lines and a 20 amp for lifhts, larger air compressor, bench etc.
The plasma takes 20amp input

[Geezer in NH]

Another advising to hire an electrician. Keep your insurance co happy so if God help your house burns down you will get paid.