Conduit for #6 wire

joey b

I am planning to run 6-3 with a 6 gauge ground to my garage. While running through the house is there any flexible conduit in which I can run all of those wires? The largest flexible conduit I could find was 3/4" but from what information I could find that is going to exceed 40% of the conduit capacity. If I use a 10 AWG ground would that still exceed the fill amount? Could I make 2 conduit runs- 1 with a hot and a neutral and 1 with a hot and the ground and have them bundled together? I'm really just looking for what may be easiest for running THHN without the use of rigid conduit.

jamiedolan

Why can't you use ridgid conduit?

Can you run RNC (grey plastic) for the entire run?

When your running the conduit inside, where is it running? Anywhere that it would be consider exposed to physical damage, basically no flexiable material is allowed.

Maybe you can explain more about where it is going to be running inside and why you don't want to use ridgid conduit.

The fill capicity is different with all the different types of conduit, what fits in 3/4" EMT does not fit in 3/4" ENT flex. 3#6awg and a #10 ground will fit in 3/4" EMT.

Jamie

Stubbie

3/4 FMC (flexible metal conduit) common at the big box stores will accept 4 #6 conductors. Fittings are readily available. Larger sizes can be found at electrical supply houses. With the the economy what it is they will sell to the public in most cases.

All 3/4 flexible conduits except that goofy blue smurf tubing stuff (ENT) will not be overfilled with 4 #6's.

What exactly are you doing? Sub-Panel? What size sub-panel?

Speedy Petey

Joey, you say "6-3". Are you saying you want to run cable inside the conduit>?
If so, why?

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

J. V.

Are you installing a panel in the garage? If the garage is attached to the house you can run 6/3 NM all the way. No conduit needed. And no need for a main breaker either.

If the garage is not attached you can run 6/3 NM inside to a junction box, then conduit from there to the garage. You do not want to put cables in conduit. Use individual conductors (wires) in conduit. THWN would be the wire to use if the conduit is buried. I believe this is what Speedy was eluding to.

220/221

3 #6's and a #10 will install easily in 3/4" AL flex provided you install the wire first.


Get your length, cut your flex and conductors, push a fish into the straight flex, attach the wires and pull them thru. You are just making a very long whip.

joey b

The garage is detached. I want to run thhn for the 65 amp capacity vs uf with the 55 amp capacity. I can also get the thhn for cheaper. The reason for the flex conduit is because i would have to make more bends than i would like to get to the panel. It isn't just a single turn to get there. I will be putting a sub panel in the garage. And no i wasn't planning on using 6-3 cable. I just misreferenced the idea of running 3 #6 cables.

jamiedolan

Is the conduit inside going to be in walls and in floors - so it is not exposed? If so, then you can use flex. If it is exposed (then it is subject to physical damage), such as running below the joists, then your only option is to use ridgid.

Also you must not have more than 360 degrees of bends in between junctions.

Jamie

Stubbie

Joey

Just some observations...first and this is being a bit picky thhn is rated thhn/thwn if its modern wire... when your talking about going underground in conduit you are using it under a wet location application and use the thwn rating. Thhn in itself is not allowed underground. The insulation must have the w in the rating. So much for that.

To use the 65 amp capacity is allowed if the entire run is in some form of conduit and both the house panel and subpanel are rated for 75c terminations. Most likely they are as all modern panels are rated for 75 C. However, there is no 65 amp double pole breaker so you can either protect it with a 70 which will require a #8 ground wire or a 60 which will allow you a #10 ground wire.

So it isn't necessary to run a #6 ground is my point. From 30 to 60 amps of protection requires a #10 copper for equipment ground. Over 60 to 100 amps requires a #8 copper egc.

Flexible metal conduit is not allowed for direct burial but I think you mean that part of the feeder that is before going underground.

Installer

Call your local "ELECTRICAL" supply store not the big box stores. Their prices are abou the same but the knowledge is much better

Cow

Bottom line-Flex is not going to work for you. No matter what kind of flex you use, you can't have more than 360 degrees of bend. So, unless you like setting j-boxes every 4 quarter bends when you run flex, you should just run cable. Whether that's Romex/SER, it doesn't matter. Set a J-box to transition to pipe when you run outside and then run THWN to your garage.

joey b

Yes, the wiring is thhn/thwn/etc/etc. I was going to drill holes through the joists, unless that is not advised/allowed. If I run rigid conduit, do I simply attach it to the underside of the joists? BTW, I have not done any other work that is displayed in these pictures.

jamiedolan

Yes, just run it below the joists, use straps to secure it. Drill a hole through the wall between the rooms if necessary. Irwin Speedbor style bits work well.

I suggest you get Ridgid non-metalic conduit, the grey pvc stuff. It is rated for burial and exposed work. It is pretty easy to work with. You need to use pvc cement to bond your joints.

This does not look like a hard run, should not take you more than a couple hours to run it.

Jamie

J. V.

I totally agree. Not to mention flexible conduit is a pain in the ass and looks like s##t.