600SL
Well-known member
Will pulling 7 #12 THHN conductors through 1/2" EMT be difficult. Will lube be required.
Any tricks?
Thank You
John
Any tricks?
Thank You
John
Pulling 7 #12 through 1/2" EMT
- Thread starter 600SL
- Start date
JoeFin
Well-known member
Ya - use 3/4
Never ever go the minimum- always leave room for changes
Never ever go the minimum- always leave room for changes
Pulling depends on length of run and more importantly how many bends. Its easy to pull seven #12 in a short run, make it longer and it might not be. Not sure I've heard of or ever seen anyone use lube to pull into 1/2 emt.
laser3kw
Well-known member
7?
would that be 3 120v circuits (3 blk, 3 wht and a ground)?
just asking for my own knowledge.
I am thinking of running (2) 220 circuits (4- 12ga wires + ground), but wasn't sure about conduit fill
would that be 3 120v circuits (3 blk, 3 wht and a ground)?
just asking for my own knowledge.
I am thinking of running (2) 220 circuits (4- 12ga wires + ground), but wasn't sure about conduit fill
Delta74
Well-known member
it should pull thrue, not sure about your fill thou, think you may be over, but yea lube can help if there are lots of bends or long pulls, just use a proper wire lube, not whatever you have handy, HD sells it along with most other places, its been designed to not break down the insulation on the wires, its probably too late now, but I know when we do long runs on a commercial job, we will often dump some lube in the conduit as we are doing the runs in places we know will give us problems.
and agree, I hate 1/2 inch, I try to avoid it whenever possible and upsize to 3/4, just in case.
and agree, I hate 1/2 inch, I try to avoid it whenever possible and upsize to 3/4, just in case.
Mustang51js
Well-known member
Anything over two bends and some distance you will have trouble doing it by yourself, if you can have someone push the wires as you pull them. If you can run 3/4 emt. How many bends do you plan on having.
rev1
Well-known member
laser, Someone else can jump in but for 220~240 circuits, I'd recommend 10 ga. I'm planning on using 12ga for my 120v circuits and 10 ga or maybe even 8 ga for my 240v circuits.
Stuart in MN
Well-known member
You need to go to a 3/4" conduit for that many #12 wires, 1/2" is too small. You didn't mention what the wires are for so I can't comment on whether you have to consider derating them for current carrying capacity.
(9) #12 THHN is the max by code. Not a smart thing to do in 1/2" but legal. I normally cut 1/2" off after (4) #12 conductors. You can pull (7)#12 in a 1/2" pending bends (360 max between boxes) length and your ability to feed the wire and serve the head on the fish tape. I would recommend 3/4".
The best way to insure a successful install is minimum bends and square cuts that are reamed smooth.
When pulling wire the three most important things are a good feed, a smooth staggered head and steady pull strokes. You would be amazed at how much more difficult a pull becomes when the wire is fed incorrectly and your timing is off . One should group the conductors avoid crossing and basically push it into the conduit. Usually the Apprentices job.
You pull with 2' to 3' strokes allowing the feed man to reposition for the next push between strokes.
Its amazing how fast and easy you can pull wire with two guys that develop timing. You develop codes like two taps on the pipe with your linesman pliers when you are ready to pull. Listen for two taps from the feed man when his ready to take off . Use multiple taps for a stop in case you get tangled up.
Normal the minimum I use is 3/4", I use 1/2 when necessary like jumps between can lights with boxes that have 1/2" KO, single switch drops, single circuit devices etc. More often than not our minimum specification on projects is 3/4"
The best way to insure a successful install is minimum bends and square cuts that are reamed smooth.
When pulling wire the three most important things are a good feed, a smooth staggered head and steady pull strokes. You would be amazed at how much more difficult a pull becomes when the wire is fed incorrectly and your timing is off . One should group the conductors avoid crossing and basically push it into the conduit. Usually the Apprentices job.
You pull with 2' to 3' strokes allowing the feed man to reposition for the next push between strokes.
Its amazing how fast and easy you can pull wire with two guys that develop timing. You develop codes like two taps on the pipe with your linesman pliers when you are ready to pull. Listen for two taps from the feed man when his ready to take off . Use multiple taps for a stop in case you get tangled up.
Normal the minimum I use is 3/4", I use 1/2 when necessary like jumps between can lights with boxes that have 1/2" KO, single switch drops, single circuit devices etc. More often than not our minimum specification on projects is 3/4"
sberry
Banned
If 9 is legal he is well under with 7. I probably wouldn't plan it that way but if its the way is is then its fine too.
volleyball
Well-known member
I say get your 7 wires and pull it through a section of 1/2" to get a feel for it. Nothing wasted and you know before you try it. I agree the upcharge to 3/4 is nothing.
He is perfectly legal. (7) #12 THHN " STRANDED" in a 1/2" conduit CAN pull fine and have no problems if you set up correctly. Depends on your ability not to cross them up when feeding, keeping them straight and smooth is paramount. I can see an inexperienced person getting into difficulty with this. You twist them while feeding ....it will go south in a hurry.
Damaging the conductors is very possible. Hence the reason I recommend 3/4"
+ 1 more for upping to 3/4". It's slightly more expensive (but still close to nothing) and sure you may not have a 3/4" bender, but you'll be glad you upgraded.
Make sure your pull head is as small and tight as possible. Some guys insist on stripping out every conductor and hooking them all through the fishtape or string...this makes them not pull off easily, but with a head that big you won't be able to pull worth a damn. I would strip 2 or 3 out, loop them through, and stagger the other wires on to them. Don't use too much tape, and make sure the tape you do use is pulled tight as possible.
Like PRH44 said, work together with a partner and your pull will go easier. If you can't grip your fishtape with your hands, use your pliers to grip it. There's no need to go buy a $40 pair of Kleins with a built-in fishtape puller, any linemans pliers worth their salt will be able to grip a fishtape right under the rivet, opposite the cutting edges.
Make sure your pull head is as small and tight as possible. Some guys insist on stripping out every conductor and hooking them all through the fishtape or string...this makes them not pull off easily, but with a head that big you won't be able to pull worth a damn. I would strip 2 or 3 out, loop them through, and stagger the other wires on to them. Don't use too much tape, and make sure the tape you do use is pulled tight as possible.
Like PRH44 said, work together with a partner and your pull will go easier. If you can't grip your fishtape with your hands, use your pliers to grip it. There's no need to go buy a $40 pair of Kleins with a built-in fishtape puller, any linemans pliers worth their salt will be able to grip a fishtape right under the rivet, opposite the cutting edges.
Thanks for the replies everyone. I just realized that this will be a no go due to box capacity limitations of 18 cu. I'm calculating even 2 120V circuits with one ground cannot pass threw an 18 cu box with a device.
I will need to find a way of getting a 21 cu box or larger just for 2 circuits with one passing through.
I will need to find a way of getting a 21 cu box or larger just for 2 circuits with one passing through.
Aceman
Well-known member
Use a 4 square deep, the 2 1/8" deep one. You're also forgetting the raised cover you use will add some box volume as well.
Take a look at this list, you can see the cubic inch volume of each different cover. Not that it matters, a 4 square deep and a raised cover will give you lots of room, but you can see for yourself how much it adds.
https://www.platt.com/platt-electri...ID=34&CatID=1105&SubCatID=2866&navPage=2_16_0
Take a look at this list, you can see the cubic inch volume of each different cover. Not that it matters, a 4 square deep and a raised cover will give you lots of room, but you can see for yourself how much it adds.
https://www.platt.com/platt-electri...ID=34&CatID=1105&SubCatID=2866&navPage=2_16_0
mobiledynamics
Well-known member
600SL - FWIW, they make even bigger boxes. Can't recall what I have in my stash but a 4" by 3 1/4'ish deep exist. It's DEEP...
LS6 Tommy
Well-known member
Don't forget, code requires you to derate by 20% with 4-6 conductors, 30% for 7-9 & 50% for 10-20...
Tommy
Tommy
The ideal box is a 3x2 old work box that can be screwed right to the steel wall panels and covered. Would require 21 cu to pass a second circuit through it. There fore I need 4" deep.
4" square boxes will just barely fit between the corrugation's of the steel panels but I cant put a cover over them and I would have to make mounting flanges for each box that would not be covered. So it would end up looking like a hacked out hole around the box. At this point its starting to look like putting the boxes on top of the steel is the way to go.
kiatech
Well-known member
Would be a pain but possible.
LS6 Tommy
Well-known member
OK, I didn't k now what your intended current capacity was going to be. THHN is indeed rated for a max of 30A. Your math on the derating is good, you end up with a max of 21A.
12 THHN is rated for 30A, but the max allowable current rating of the circuit changes based on code. Code 110.14(C) generally limits it to 25A and code 240.4(D) often limits the protection to 20A. 240.4(G) lists the types of circuits where 12 AWG can be protected above 20 amps.
Tommy
sberry
Banned
I got some hack around boxes, I could go back and finish it a little, if I was worried I might come up with a simple way to trim them out from flashing.
Mustang51js
Well-known member
Nothing to go crazy about, just run the pipe and boxes and pull the wires, you don't even have to pull a ground if you use the emt as a ground, just ground tails from back of box to outlet. Are you just having 120 volt circuits and how many outlets.
Mustang51js
Well-known member
If pipe is nice and straight it doesn't look bad at all on the outside of the wall.
Absolutely, but for non dedicated circuits it also tends to get in the way of things like shelving etc. So it looks like the best bet is to come down from the ceiling with each box with two conductors plus ground in 1/2" EMT to the shallowest 4" box available. 12cu total or 21cu for double duplex assuming I run a ground.
volleyball
Well-known member
How are your corrugations running? If vertical, you could put the conduit in the back of the wave.