Solid or Stranded Electrical Wire??

[John Bailey]

I have to go buy wire for my new shop. I've got a pretty good handle on what I need, but I'd like to know which type of wire works best. I just wired up my wife's greenhouse, and I used solid wire, because that's what I had. The solid wire worked well, but it was a little difficult getting all the wire back into the boxes because of stiffness. The greenhouse was a small job. I wondered if the more flexible stranded wire would be better for the shop because it will be a bigger job.

John

[Charles Hans]

John, Stranded wire will do just fine as long as it is sized to match the circuit breaker sizes, It is easier to bend in the boxes, and say #12 wire will carry 25amps in either solid or stranded. It's your choice.

[Paul Kunkel]

if you use the stranded, you will have to use conduit, and it is more expensive than romex. At the Oak they say you can't put romex in conduit :) :)

[Rob Russell]

John,

It sounds like you're running conduit if you're pulling individual conductors. Stranded is more flexible - THHN/THWN is what you'd use. Do yourself a favor and oversize your boxes, it'll make the wiring job easier when you're tucking the wire back into the boxes with the devices.

Charles,

#12 may have an ampacity rating of 25 amps based on 60 or 75 degree terminals, but article 240.4(D) specifically limits the overcurrent protection for #12 to 20 amps.

Rob

[Tyler Howell]

if you use the stranded, you will have to use conduit, and it is more expensive than romex. At the Oak they say you can't put romex in conduit :) :)
Long time Paul, How you been!!

[John Bailey]

I'm running conduit through the shop for the wire. I'm using #12 with 20 amp circuits. Sounds like stranded will be easier to use.

Rob,

I bought the biggest boxes at HD. They had two sizes. Is that what you meant by "oversize?"

John

[Rob Russell]

I bought the biggest boxes at HD. They had two sizes. Is that what you meant by "oversize?"


Yep. Give yourself the extra work room.



At the Oak they say you can't put romex in conduit :) :)


It's actually an NEC requirement that you protect NM cable in certain circumstances and sleeving it in conduit would accomplish that.

Article 334 is specific to NONMETALLIC-SHEATHED CABLE: TYPES NM, NMC, AND NMS.

Article 334.15(B) Protection from Physical Damage, reads "The cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means."


That section continues with "Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, or other approved means extending at least 150 mm (6 in.) above the floor."

So, not only is NM in conduit allowed, in some cases it is required to be protected and conduit is one way of doing that.

Rob
Addy protocol: Experienced but unlicensed, homeowner who enjoys wiring

[tod evans]

john, when i wired i pulled 10ga stranded (thhn) for all my 110 circuits. the 220 single phase circuits are all 6ga and fitted with the appropriate breaker for the machine. my theory is that should i ever need to change equipment/motors all that will be required is a breaker. going oversized on wire really doesn`t cost much in the beginning and won`t hurt your equipment one bit and for me the flexability made sence. .02 tod

[Cliff Rohrabacher]

Multi strand carries more current. If that's an issue then it's a great way to go.

When I run a sub-panel or a high energy circuit I prefer multi strand wire.

[Tyler Howell]

Invest in good outlets and get a good secure connection. Often when people use stranded they fail to get a solid connection on the outlet and switches.
(No push-in connections) They're legal but cause problems down the line. The type with a good screw down captive connection work slick;)

[tod evans]

Invest in good outlets and get a good secure connection. Often when people use stranded they fail to get a solid connection on the outlet and switches.
(No push-in connections) They're legal but cause problems down the line. The type with a good screw down captive connection work slick;)

good advice tyler! i used crimp on forked terminals for the 10ga and lugged receptacles for the 6ga. for the 110 receptacles look for "hospital grade" a bit more money but you won`t have to do it again...02 tod

[Rob Russell]

john, when i wired i pulled 10ga stranded (thhn) for all my 110 circuits and outfitted them with 30amp breakers. the 220 single phase circuits are all 6ga and fitted with the appropriate breaker for the machine. my theory is that should i ever need to change equipment/motors all that will be required is a breaker. going oversized on wire really doesn`t cost much in the beginning and won`t hurt your equipment one bit and for me the flexability made sence. .02 tod

Tod,

FYI, wiring the 110v circuits with #10, protected by a 30 amp breaker and using either 15 or 20 amp receptacles is a direct violation of the NEC.

It's also dangerous because you now have the ability to plug in a tool like a router that can jam on a work piece and suddenly have a full 30 amp breaker to pull current from.

It's fine to wire with #10 if you want to reduce voltage drop at startup on your tools. To comply with the NEC, however, replace those 30 amp breakers with 20 amp breakers.

The applicable NEC article is 210.21(B) and table 210.21(B)(3) specifies what size receptacles may be used on branch circuits of various ampere ratings. For a 30 amp circuit, the only allowable receptacle is one rated for 30 amps - you can't put 15 or 20 amp receptacles on a 30 amp circuit. A 30 amp plug is an entirely different configuration than the standard 15 and 20 amp receptacle. Here's a link to the NEMA plug/receptacle configurations (http://www.leviton.com/sections/techsupp/nema.htm), so you can see how the 30 amp plugs won't work for you.

Rob
Addy protocol: Experienced but unlicensed, homeowner who enjoys wiring

[tod evans]

thanks rob, there are no 15 amp receptacles in my shop, the 110 is routed through 20amp hospital grade hubbles. i realize the nec doesn`t like what i`ve done and if i`m ever in a position to undergo an inspection i`ll be sure to change the breakers. .02 tod

[Rob Russell]

thanks rob, there are no 15 amp receptacles in my shop, the 110 is routed through 20amp hospital grade hubbles. i realize the nec doesn`t like what i`ve done and if i`m ever in a position to undergo an inspection i`ll be sure to change the breakers. .02 tod

Tod,

What you do in your shop is your business and I wouldn't begin to tell you otherwise. I would politely suggest, however, if you're going to post on a public forum like this - that what you post comply with the NEC. If you still want to post what you have done in your shop, do so - but also state what the code-compliant installation is and that you have consciously ignored the NEC.

Otherwise, if "someone" read your post and replicated what you have in your shop without understanding the potential safety hazards, "someone" could get hurt.

Rob

[tod evans]

Tod,

What you do in your shop is your business and I wouldn't begin to tell you otherwise. I would politely suggest, however, if you're going to post on a public forum like this - that what you post comply with the NEC. If you still want to post what you have done in your shop, do so - but also state what the code-compliant installation is and that you have consciously ignored the NEC.

Otherwise, if "someone" read your post and replicated what you have in your shop without understanding the potential safety hazards, "someone" could get hurt.

Rob

very true rob! please don`t follow my lead folks, rob speaks the truth, getting bit (shocked) ain`t no fun! in fact i`ll edit my original post and remove the amperage rating of the breakers...02 tod