Why does this 4" PVC conduit OD measure 4.625" vs 4.5"

[Installer]

Why does this 4" PVC conduit OD measure 4.625" vs 4.5"? I'm pretty sure we had the
Carpenter Tee's aligned. Problem is we have to cut this PVC and reduce it to 2" and I'm
not sure what to buy.

 

[PaulMmn]

It hasn't been squished into an oval, has it??

Or sagged down in the heat??

 

[LarryFine]

The gray straight-edge on the left does not look quite perpendicular to the square; it will hit the marks on the two edges of the square equally when it is.

Regardless, conduits are measured by inside diameter, so a regular 4"-to-2" reducer should fit it. Measure the reducer's sockets when you pick one up.

 

[Installer]

I'm correcting someone else's mistake.
Inside that 4" duct there's an electrical line .
The electrical line is running through a communications box, which is against code.
My plan is to carefully cut the 4" PVC duct (without damaging the conductors inside)
and take a 8" x 8" x 4" Nema 4R box and put a box adapter on it as shown on the right.
Then we flip it upside down and put it on top of that 4" duct and reroute the electrical ine
to a new Panel/Disconnect and TVSS. I can't find a box adapter that will slip inside the PVC or outside it.

 

[retirede]

To get an accurate OD measurement, use 2 squares.

 

[zbang]

To get an accurate OD measurement, use 2 squares.

Measure ID, measure wall thickness, add. (I'll occasionally put two squares on one beam to make a caliper.)

 

[dkidd]

which is against code.

What code?

 

[Barbqranch]

Measure circumference and divide by pi.

 

[PaulMmn]

I'm correcting someone else's mistake.
Inside that 4" duct there's an electrical line .
The electrical line is running through a communications box, which is against code.
My plan is to carefully cut the 4" PVC duct (without damaging the conductors inside)
and take a 8" x 8" x 4" Nema 4R box and put a box adapter on it as shown on the right.
Then we flip it upside down and put it on top of that 4" duct and reroute the electrical ine
to a new Panel/Disconnect and TVSS. I can't find a box adapter that will slip inside the PVC or outside it.

Are the duct and the box adapter the same diameter? And, if so, is there a female-female sleeve that will slide over the two ends?

Is the next-size-up duct a big jump, or only and inch or so. Would it work as a sleeve?

 

[synchro]

Could you be looking at the end of a thin wall EB-20 duct where it flares out to an I.D. of 4.5" in order to connect to another length of duct?

I think you should get a real caliper so there's no guesswork. Even very inexpensive ones would be up to the task.

 

[Installer]

What code?

]National Electrical Safety Code (NESC), Section 320 B 2, Separation From Other Underground Installation. It states, "Separations Between Supply and Communication Conduit Systems: Conduit systems to be occupied by communication conductors shall be separated from conduit systems to be used for supply systems by 75 mm (3 in.) of concrete, 100 mm (4 in.) of masonry, or 300 mm (12 in.) of well-tamped earth."

]When telecommunications cables are routed nextto large electromagnetic fields, surplus voltage andcurrent can be induced on them. If the power levelof the electrical cable is large enough, the electricalnoise can interfere with operation and performance ofthe telecommunications applications running on thecabling. Electrical and data systems designers must befamiliar with this phenomenon and ensure that the twosystems can work in harmony.

 

[Jraef]

is it a trick of the image, or is that white, not grey? Because I'm wondering if someone used drain pipe...

 

[K8MHZ]

is it a trick of the image, or is that white, not grey? Because I'm wondering if someone used drain pipe...

That does look like a possibility.

 

[junkhound]

The gray straight-edge on the left does not look quite perpendicular to the square; it will hit the marks on the two edges of the square equally when it is.

QUOTE]

+1 the squares are not square, check the other leg of the blue square, should read the same. Even on the pic, one edge of the blue is closer to 4-9/16, the other 4-5/8 = NOT square.

as the bard saith, much ado about nothing.

 

[LarryFine]

as the bard saith, much ado about nothing.

I thought it was "sayeth".

 

[junkhound]

You are correct, the bard 'hiself' always used the -eth form

 

[roger]

]National Electrical Safety Code (NESC), Section 320 B 2, Separation From Other Underground Installation. It states, "Separations Between Supply and Communication Conduit Systems: Conduit systems to be occupied by communication conductors shall be separated from conduit systems to be used for supply systems by 75 mm (3 in.) of concrete, 100 mm (4 in.) of masonry, or 300 mm (12 in.) of well-tamped earth."

]When telecommunications cables are routed nextto large electromagnetic fields, surplus voltage andcurrent can be induced on them. If the power levelof the electrical cable is large enough, the electricalnoise can interfere with operation and performance ofthe telecommunications applications running on thecabling. Electrical and data systems designers must befamiliar with this phenomenon and ensure that the twosystems can work in harmony.

So why is this work under the NESC?

Roger

 

[LarryFine]

You are correct, the bard 'hiself' always used the -eth form

I thought it was "hisself".

 

[dkidd]

]National Electrical Safety Code (NESC), Section 320 B 2, Separation From Other Underground Installation. It states, "Separations Between Supply and Communication Conduit Systems: Conduit systems to be occupied by communication conductors shall be separated from conduit systems to be used for supply systems by 75 mm (3 in.) of concrete, 100 mm (4 in.) of masonry, or 300 mm (12 in.) of well-tamped earth."

]When telecommunications cables are routed nextto large electromagnetic fields, surplus voltage andcurrent can be induced on them. If the power levelof the electrical cable is large enough, the electricalnoise can interfere with operation and performance ofthe telecommunications applications running on thecabling. Electrical and data systems designers must befamiliar with this phenomenon and ensure that the twosystems can work in harmony.

It doesn't seem that your proposal will bring the installation into compliance.
A metallic raceway might mitigate the noise concern.

 

[Installer]

1. Insofar as the measurement: I went home and got some 40, 60 80 and 120 grit Sandpaper and took 1/8" off of the outside of some PVC I had in my garage.
2. Tomorrow I will try taking 1/16" off of the inside of the female fitting and 1/16" off of the male fitting.
3. Insofar as the NESC, NEC, and other codes and running power through a Communications Box-- part of the reason I'm fixing this is because there are local site practices and even company practices that you have to follow and be respectful of and though you guys may be right or are probably 101% right, I have to follow our rules

Thanks everyone for your help!