Tricks for Identifying Existing PVC?

Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
Trying to provide an estimate for a job and part of the run is underground PVC that stubs up to and through the building to a timer, then transfers to EMT. The portion of PVC that is visible above ground is painted.

I was just wondering if anyone had any tricks for identifying existing PVC.
I was able to determine it was 1/2" PVC via it's Outer Diameter (OD), but have no idea if it's Schedule 40 or Schedule 80.

The only (2) things I can think of are (1) dig down until I find some insignia on the PVC... or (2) disconnect/cut a section and measure the Internal Diameter (ID).

I'm trying to compose the estimate before I have to do any actual digging and or tinkering with the existing, but if the above (2) options are the only available methods, I might be stuck...

Thoughts?
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
Any PVC underground is not required to be sch 80. If the run is existing, what does it matter which it is? Are you just trying to see if there's room for more conductors? If you can take it loose where it transitions, you can see what it is. The sch 80 will much thicker inside resulting in a smaller ID.
 

Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
Any PVC underground is not required to be sch 80. If the run is existing, what does it matter which it is? Are you just trying to see if there's room for more conductors? If you can take it loose where it transitions, you can see what it is. The sch 80 will much thicker inside resulting in a smaller ID.
Yea. Schedule 80 vs. Schedule 40 it is about conduit fill.

I'm aware I could take it apart and measure the ID.

I was just wondering if anyone had any other tricks because it would be an hour of work minimum to drive out there, de-energize the circuit, cut the PVC somewhere, pull back the wire, measure the ID, piece it back together, etc., ...all prior to getting any official estimate to the customer for the true scope of work (i.e. before technically being hired for the job).

I was thinking I could just utilize a "worst case scenario" type of logic and just assume it's Schedule 80 for the purposes of conduit fill.
 
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Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
Depends...one of the State inspectors reminded us in a newsletter that if the 90 extends above 18” below ground level, it needs to be Schedule 80.
I still have to get over the fear of running PVC above ground, haha. I would never extend an underground PVC run above grade. I would always transfer to metal conduit.

I used to do all my underground feeds in RMC, but I'm getting to the point where I'm starting to rethink that and consider PVC. Still, once it's above grade, I can't even fathom doing anything but EMT, IMC, or RMC, lol. The thought of the PVC breaking just scares the crap out of me, lol.

I believe some local municipalities around Chicago are actually creating amendments that outlaw PVC entirely for electrical work, but I could be wrong. They are strict around these parts. Some villages won't allow us to use more than 3 ft. of FMC for anything but whips from disconnects to appliances.

I've never worked with PVC aside from a year of working on Cell Towers where the feeders were done in PVC. Everyone I've ever worked for has always used metal conduit.
 
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FionaZuppa

Senior Member
Location
AZ
1sec.... You are estimating a job? A job to do what? Are you replacing something, or is the job all new. Kinda confusing as you say "estimating a job" but then go onto describe some existing materials & configuration.

All new - sched 40, then turn up the risers using sched 80. Done. (dunno what fill you might have, but watch the fill ratio in the smaller sched 80, etc).
 

FionaZuppa

Senior Member
Location
AZ
Estimate a price for for both, submitting the higher. If awarded the job, order both. Install the size you need, return the other.
Why bother, sched 40 the bury, sched 80 the turn up's. Why would it be done any other way with PVC?
If the "riser" is really long, I might argue you can switch back to sched 40 when the conduit is no longer needing "protection".
 

480sparky

Senior Member
Location
Iowegia
Why bother, sched 40 the bury, sched 80 the turn up's. Why would it be done any other way with PVC?
If the "riser" is really long, I might argue you can switch back to sched 40 when the conduit is no longer needing "protection".
Maybe it's not an entirely new install. Perhaps it extending what's already there.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Trying to provide an estimate for a job and part of the run is underground PVC that stubs up to and through the building to a timer, then transfers to EMT. The portion of PVC that is visible above ground is painted.

I was just wondering if anyone had any tricks for identifying existing PVC.
I was able to determine it was 1/2" PVC via it's Outer Diameter (OD), but have no idea if it's Schedule 40 or Schedule 80.

The only (2) things I can think of are (1) dig down until I find some insignia on the PVC... or (2) disconnect/cut a section and measure the Internal Diameter (ID).

I'm trying to compose the estimate before I have to do any actual digging and or tinkering with the existing, but if the above (2) options are the only available methods, I might be stuck...

Thoughts?
You could mic it...
PVC 40 sidewall is .109 vs .147 for schedule 80

The easiest thing would be to take a small piece of schedule 40 and compare it. It’s a noticeable difference. I’m sure you can find some in the trash somewhere. 1/2 schedule 40 isn’t hard to round up a small 6” piece of scrap.
 

Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
All this trying to figure it out, I would have already sent my quote to cust.
All about conduit fill for upsizing the wire for VD. Total circuit length is 540 ft total from source to load and back. That adds up depending on if, for example, I use #8's or #10's.
 

Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
Perhaps....see if it is possible to have someone remove some of the paint?

In terms of conduit fill in 1/2"......what is the difference......one, maybe two wires?
I was thinking I could try to scratch some of the paint off, but worried that might take off the label on the PVC itself.
 

Jerramundi

Senior Member
Location
Chicago
Occupation
Licensed Residential Electrician
You could mic it...
PVC 40 sidewall is .109 vs .147 for schedule 80

The easiest thing would be to take a small piece of schedule 40 and compare it. It’s a noticeable difference. I’m sure you can find some in the trash somewhere. 1/2 schedule 40 isn’t hard to round up a small 6” piece of scrap.
I was trying to complete the estimate before I started any work, like taking the existing apart to measure the ID.

I just thought might be some trick I was unaware of other than measuring the ID.
 
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