pulling THWN wire through long conduit, which type to use, how difficult ?

[RustyShackleford]

I think this is one of those "picture is worth 1000 words" situations. The existing subpanel is on the wall below the catwalk; so the conduit will come up vertically, about 20ft, and then run along the bottom of the catwalk to the parking area. EVSE probably mounted on the railing 6x6 post, where the catwalk ends at the parking area.

I feel like romex suspended by wire, under the catwalk, would be pretty hairbag. Plus, I already bought the wire.

 

[begreen]

The original post says "along the bottom of a catwalk" so I assume it would be supported by the catwalk. PVC conduit definitely would not be suitable for a 50' span in free air.

What is the ruling on the ground wire for a dedicated 220v circuit? Does the gnd wire gauge need to be the same as the hot legs or can it be a gauge or two below the current carrying legs?

 

[RustyShackleford]

What is the ruling on the ground wire for a dedicated 220v circuit?

My vague recollection is that if the conductors are 10awg or smaller, the EGC must be same size, but it's ok to stick with 10awg EGC for 6 and 8awg conductors. I think this chart supports that ...

Size of Equipment Grounding Conductors | UpCodes

Explore a searchable database of US construction and building code. Code regulations are consolidated by state and city for easier navigation.

up.codes

Anyhow, I've already purchased three lengths of 10awg wire (2 hots + EGC) so it's moot here.

I plan to go with 1" PVC conduit, as recommended here (only $20 more for the seven 10ft pieces I need). That should allow me to later pull 8awg if need be, which is good for 40amp EVSE (50amp OCPD).

 

[Ashful]

I think this is one of those "picture is worth 1000 words" situations.

Yeah... all clear, now! Had thought this was going to be one of the more common aerial runs between buildings, when I had mentioned the tension cable.

 

[RustyShackleford]

I'd actually rather not be trying to pull wire through a conduit body where the vertical and horizontal runs come together, since it'll be 25ft off the ground (underneath that catwalk ) - so I'd prefer just to put a 90-degree elbow there. With 1" conduit, should I be good pulling the whole thing at once, without a conduit body at the 90 ?

 

[brenndatomu]

A 1" conduit sweep 90 should make that a pretty easy pull...all in one shot.
Were you thinking of using an LB there? That's be a pain.

 

[RustyShackleford]

A 1" conduit sweep 90 should make that a pretty easy pull...all in one shot.
Were you thinking of using an LB there? That's be a pain.

Thinking of using a sweep elbow instead of an LB. Don't fancy being 25ft up on a ladder trying to pull wire through an LB. Those sweep elbows are hard to find though - $20+ before shipping. I'm going to try bending a piece of straight conduit - don't need a tight radius at all.

 

[gthomas785]

Yes I'd recommend the sweep. You can have up to 360 degrees of bends before a conduit body would be required.

 

[EbS-P]

Thinking of using a sweep elbow instead of an LB. Don't fancy being 25ft up on a ladder trying to pull wire through an LB. Those sweep elbows are hard to find though - $20+ before shipping. I'm going to try bending a piece of straight conduit - don't need a tight radius at all.

Your friend has shared a link to a Home Depot product they think you would be interested in seeing.

Carlon 1 in. 90-Degree Schedule 40 PVC Belled End Standard Radius Elbow UA9AFB-CTN - The Home Depot

The 1 in. 90 Belled Standard-Radius Elbow is designed for above and below-ground use as described in the National Electrical Code. It is crafted with schedule 40 PVC and is sunlight resistant for use in outdoor and exposed areas. The elbow is ETL and UL listed to help ensure safety.

www.homedepot.com

 

[gthomas785]

Where are you shopping that elbows are hard to find? My Home Depot has a bin of every size 90, 45, 22.5 degree sweeps and they're a few bucks apiece.

 

[brenndatomu]

Where are you shopping that elbows are hard to find? My Home Depot has a bin of every size 90, 45, 22.5 degree sweeps and they're a few bucks apiece.

X2...should be in stock anywhere that sells PVC conduit...super common

https://www.lowes.com/pd/Kraloy-1-in-PVC-Conduit-90-730-Standard-Radius-Elbow-SCH40-Plain-End/5001228603

1" PVC 90-Degree Schedule 40 Conduit Elbow

one-inch Schedule 40, Standard 90-degree elbow with a belled end is lightweight and easier to install.

www.menards.com

 

[RustyShackleford]

Where are you shopping that elbows are hard to find? My Home Depot has a bin of every size 90, 45, 22.5 degree sweeps and they're a few bucks apiece.

By "sweep elbow" I thought we were talking about the "special radius" ones that Cantex lists in their catalog; they make ones with radii of 18, 24, 36, and 48". Thought that might make it even easier. Did find a 36" radius one for $18 delivered on eBay; seems worth it, to make the pull even easier, especially if I might go back with #8 wire some day. Still wondering how easy it would be to just bend a straight piece.

 

[brenndatomu]

Still wondering how easy it would be to just bend a straight piece.

If you have a heat gun and 10-15 minutes to patiently (have to keep moving, its easy to burn a black spot on the pipe) get the plastic up to about 225*F (IIRC) you can tie PVC in a knot if you want.
I made a bunch of custom PVC brackets at work a few years ago by putting some 1/2" thick PVC in the oven at 225* (again, IIRC) and then dropping each piece in a jig/mold for 10 minutes or so while it cooled/hardened...it worked great!
For pipe/conduit it works well to blow on and through it with an air hose once you get it in the shape you want...it will re harden in 30-60 seconds
Interesting https://pvcbendit.com/pages/pvc-pipe-bending-faqs

 

[gthomas785]

Sure, lots of youtube videos on bending pvc if you want to go that route. Personally I think you are overestimating the difficulty of essentially a textbook pull, and you've made it even easier by oversizing the pipe.

 

[brenndatomu]

Sure, lots of youtube videos on bending pvc if you want to go that route. Personally I think you are overestimating the difficulty of essentially a textbook pull, and you've made it even easier by oversizing the pipe.

Agreed

 

[semipro]

Gray PVC takes paint well if you don't like the gray look. Your catwalk looks nice enough (real nice BTW) that painting the PVC brown might be worth the trouble.
I don't think you'll need the higher radius elbows, just what you can get at the store now. Make sure you orient the pipe and fittings the right way to make things easier.
I think you'll find the pull easier than you think.
Don't forget to leave a pull cord too.

 

[RustyShackleford]

Yeah, I'm overthinking this, but the engineer's motto: anything worth thinking is worth overthinking

So I'll just use a standard elbow. And yes, a pull cord, so I need a piece of cord double the length of my pull.

Thanks for catwalk compliment. PVC will be under catwalk, of course, so hardly visible at all (the yard below there is not a place where you'd hang out) - except where it comes up to the EVSE at the end.

 

[Ashful]

Standard sweep elbow, this is an easy pull. But do learn the heat gun trick for making your own end bell slip joints. I don't bother making elbows, unless an odd angle is required, but I do make my own end joints in PVC conduit. This is the best way to make custom lengths, and not need couplings all over.

I do this work with a heat gun if I'm in my shop, or a torch if working outdoors, but I see this guy found a "tool-less" way to do the same.

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[RustyShackleford]

One more question, guys: Do I need to use Schedule 80 conduit ? I'm not getting this inspected, but I want to do the right thing. Code says Schedule 40 is ok if it's "not susceptible to damage". I THINK that's true: it'll come up the side of the building (coming out of the subpanel about. 4ft off the ground) and then up to the underside of the catwalk, and along it to the parking area. I'll probably transition to liquid-tight where it comes up from under the catwalk into the EVSE (just for convenience, since the routing will be complicated).

 

[brenndatomu]

No need for 80 here, just make sure its well supported, you'll be fine

 

[gthomas785]

Rule of thumb: if it's above eye level, it's probably not subject to damage. If it's below waist level, it probably is.
The only person who can determine such a subjective code requirement is the AHJ. Since you're not getting it inspected, you are the AHJ. So use your best judgement.

 

[RustyShackleford]

You guys have been so helpful ! Any thoughts about the best caulk to seal places where I've made penetrations in the basement cinderblock wall ? A lot of the gaps are too small to want to use spray foam, plus most are places I'd like a neat look. There's caulk meant for concrete, tempted to use it. Or maybe RTV silicon ?

 

[semipro]

If you're not going to paint it, one good option is GE Silicone Version 1.
I've had problems with their version 2.
There are a lot of good options out there now for caulks but the GE Silicone on my house has stood the test of 30+ years of time very well.

 

[RustyShackleford]

If you're not going to paint it, one good option is GE Silicone Version 1.
I've had problems with their version 2.

The v1 is the OG with the strong vinegar smell, and the v2 is the one without ? I opened up an old tube of v2 recently and it had gotten REALLY weird; turns out there is a hard expiration date.

 

[peakbagger]

V1 can be acidic, V2 uses alcohol for curing and is non acidic but more expensive. I am fan of the Sikaflex line of polyurethane sealants, many will take paint, silicone does not.

A lot of sealants have had to be reformulated due to VOC regulations and the newer low solvent water based reformulated products tend to have very firm expiration dates. Most folks used to ignore those dates but its real important to check. I knew someone doing a construction job who bought a case of construction sealant that was just a couple of months out of date and it was too stiff to pump out of a caulking gun.