dry or wet 90 degree Romex

[uparms]

36x30 unattached and not heated. Probably 100 amp coming from the house 200 amp panel.

Planning on the wiring job. Been advised to use 12/2 Romex for the whole job except the 240s .

15 or so 20 amp receptacles and 12 to 18 boxes for florescent lights.

Can I use 12/2 for the all these and do I need indoor or outdoor romex. I will be using 90 degree Romex. Standard stick build with brick or siding exterior.

Will also have 3 direct 6AWG for 1)7.5 compressor motor and 2) 2 240 welding outlets.

 

[sberry]

Dry for the building.

 

[Charles (in GA)]

Well, Romex™ is a registered trademark of the Southwire Corporation of Carrollton, GA. Romex is a type of NM (Non Metallic) cable whose uses are described in Article 334 of the NEC. It is not permitted to be used in a "damp or wet location", nor underground.

The "wet Romex" you describe is technically known as UF, or underground feeder, and is described in Article 340 of the NEC and can be used in wet, damp or dry locations both above and underground. It is quite expensive compared to NM and inside a building, you would have no reason to use it.

Also, there is no logical reason to use 20 amp rated receptacles for the 120v circuits. Code allows the use of 15 amp receptacles on 20 amp circuits and if you use a good quality spec or commercial grade receptacle, you will have just as good a receptacle as using a 20 amp rated one. The only difference is in the faceplate slot configuration on these higher quality receptacles. I doubt you have or will have any equipment with 20 amp/120v plugs on the cords. Very uncommon to find these.

Charles

 

[rlitman]

What he said. Also, UF (AKA NM-C) is harder to strip than regular NM made for dry use.

 

[pattenp]

what he said. Also, uf (aka nm-c) is harder to strip than regular nm made for dry use.

nmc-b

 

[uparms]

NM it is? Thank you.

 

[justsam]

Not sure how many lights will be on one circuit, but you might consider the use of 14 ga for the lighting circuits. Slightly cheaper and easier to work with. Certainly nothing wrong with all 12ga and keeps breaker tsizes to a minimum.

Don't forget circuits for garage door opener(s) if applicable.

Receptacles must be GFCI protected either by using a line/load receptacle at the beginning of the branch circuit, or GFCI breakers. I am a fan of the breakers even though they cost more, because all GFCI resets are at the panel location and don't get buried behind cabinets, etc.

You may want to check with jurisdiction if they require tamper resistant. It is required for a residential detached garage, and it may be the only type receptacle you can now find.

 

[uparms]

Hope ro do 12/2 for all. 18 dual tube florescent , multiple circuits for lights and 12-14 receptacles. 2 G door openers. 2 external spots, 1 external waterproof outlet.
3 audio, 1 coax, 1 cat 5 from house.

Hope to have a 100 amp out to the garage, compressor at 7.5 HP on 40 or 50 amp breaker, 2 240s for welder connections.

 

[Mustang51js]

Why wouldn't you run the 240 volt lines in nm cable.

 

[wyliesdiesels]

Hope ro do 12/2 for all. 18 dual tube florescent , multiple circuits for lights and 12-14 receptacles. 2 G door openers. 2 external spots, 1 external waterproof outlet.
3 audio, 1 coax, 1 cat 5 from house.

Hope to have a 100 amp out to the garage, compressor at 7.5 HP on 40 or 50 amp breaker, 2 240s for welder connections.

Youre gonna need a breaker bigger than that. FLC for a 7.5hp motor is 40a! Youre gonna need 60-80a breaker! Doubt a 50a will hold...

 

[Charles (in GA)]

Youre gonna need a breaker bigger than that. FLC for a 7.5hp motor is 40a! Youre gonna need 60-80a breaker! Doubt a 50a will hold...

I have a true 7½ hp two stage compressor. While the NEC tables may list it at 40 amp, virtually every one I've seen is about 32-33 amps. I operate mine on a 50 amp breaker with #6 wire. I have 200 amp service on a dedicated meter and transformer for the shop and when that compressor kicks in, the MH lights dim (thankfully not enough to go out) and if I'm running the shop vac, you can hear it slow down. I've measured the peak start up current at 190 amp using a clamp meter.

Charles

 

[75gmck25]

FYI - I bought 12/2 NM-B wire at Home Depot about 3 weeks ago and found they had the 250 ft rolls on a close-out special. The price for 250 feet of 12/2 NM-B was lower than the price for 100 feet. I just wired everything with 12/2, even the 15 amp receptacles.

My house has both old and new wiring, and I used 20 amp receptacles on new circuits where its breakered for 20 amps, just to remind me that they have a 20 amp breaker. I have it that way on my GFCI kitchen convenience receptacle circuits, laundry room, bathroom, and my outdoor receptacles near the exit doors. From what I recall, a 15 amp rating may have been allowed on some of these circuits. However, it was almost as easy to wire 12/2 as 14/2, and I was able to find 12/2 at good prices.

Bruce

 

[Speedy Petey]

......... they had the 250 ft rolls on a close-out special. The price for 250 feet of 12/2 NM-B was lower than the price for 100 feet.

This really isn't saying much. The price for less than 250' rolls of cable is ASTRONOMICAL!!

I will say, any time you can find 250' rolls on any kind of special is good, but still compare prices. Home centers are great at making you think you are getting something on sale when it is no big savings.

 

[sberry]

Those comps are not even that big. They are 32A and I saw one a while back where it passed inspection with an 8 cable 50. I have never heard a reliable account of them nussiance tripping a 50.

 

[sberry]

FYI - I bought 12/2 NM-B wire at Home Depot about 3 weeks ago and found they had the 250 ft rolls on a close-out special. The price for 250 feet of 12/2 NM-B was lower than the price for 100 feet. I just wired everything with 12/2, even the 15 amp receptacles.

My house has both old and new wiring, and I used 20 amp receptacles on new circuits where its breakered for 20 amps, just to remind me that they have a 20 amp breaker. I have it that way on my GFCI kitchen convenience receptacle circuits, laundry room, bathroom, and my outdoor receptacles near the exit doors. From what I recall, a 15 amp rating may have been allowed on some of these circuits. However, it was almost as easy to wire 12/2 as 14/2, and I was able to find 12/2 at good prices.

Bruce

There is some confusion as to what 20A is but I really don't want them on a general circuit. I might use one on a dedicated simply to tell me there were no other loads on that wire. No one really uses 14 on recept circuits, not that you cant but for general use its so much easier and better to simply use a wire allows for a couple more outlets and gives way more overhead for intermit motor loads, increases efficiency a bit in the event you do add load, reduces v drop.
I like to save the 14 for lights and occasional equipment.

 

[sberry]

I operate mine on a 50 amp breaker with #6 wire.

It shows you how much overhead your 50 has. Still doesn't trip. A 6 wire really isn't as big as asset as one may think. It simply lets a higher inrush, just twists it all up faster. A stretch of 8 would slow things down a little.

 

[Cruisinga]

I think it has more to do with the fact that a breaker does not instantly trip at its rating. There is a time involved. Depending on the breaker characteristic curve the current has to exceed the rating for a period of time before it trips.

 

[uparms]

Thank you

 

[sberry]

I agree wire prices are about like gasoline. The juice on it all doesn't add up to much for a common home renovation, I actually buy a bit on sale and stock up. If I am really wiring a house like a 1000 so much better, it does make it easy to over do it but we just re wired a 3br 1ba with roll of 14/3, roll of 14/2 and 2 rolls of 12/2 and I got wire left over and I added a few things. 1 car garage. I only added a couple, maybe 3 circuits above legal.
I was really impressed with the cost, not bad. Homeline panel. 100/24 on sale, plastic boxes and 2 boxes of recepts and box of switches.