ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Happy Father's Day!
by Bill Addiss - 06/19/21 04:16 PM
A Risky Setup
by timmp - 06/18/21 08:08 PM
Where is Everyone?
by gfretwell - 06/18/21 11:07 AM
Conduit over Vinyl Siding
by Jim M - 06/16/21 08:30 PM
Updated Forum Software
by Admin - 06/15/21 10:23 AM
New in the Gallery:
2020 - 2021 Winter Project
2020 - 2021 Winter Project
by Bill Addiss, April 29
Garden 2021
Garden 2021
by Bill Addiss, April 26
Who's Online Now
0 members (), 7 guests, and 13 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#44383 11/03/04 12:49 AM
Joined: Oct 2004
Posts: 53
I
Member
I have a long run (1300') of PVC for some decorative lighting along a driveway. The lamps will be spaced about 130' apart. I'm wondering what the experience is regarding expansion/contraction of the PVC conduit. I know the temp down at 4' or so is pretty constant, but at 2' I'm not so sure it's constant. I certainly don't want any fittings to pull apart. Above ground, expansion fittings would be mandatory.

#44384 11/03/04 01:16 PM
Joined: Aug 2004
Posts: 54
G
Member
InspectorE,
300.5(J) ground movement,
and 300.7(B) expansion fittings.
I'm assuming that you are in a zone 3 or 4.(did a google on "frost zones")
I personally probably would not bother with the expansion fittings if you can get down to 48"...like you said, it should stay a constant 55°
anything less than 4', I would put one every 50-100'. 352.44(A) (let's say in the summer the earth is an even 55°, and in the winter it is 32°., so 1.01 inches per 100'.)

#44385 11/03/04 08:00 PM
Joined: Jun 2003
Posts: 681
P
Member
for conduit that is buried, you will not have to be concerned about expansion fittings.

Pierre


Pierre Belarge
#44386 11/03/04 11:12 PM
Joined: Apr 2002
Posts: 7,275
Likes: 2
Member
Check Carlon literature, UG is OK without exp. joints. But, you must be stubbing 'up' at the fixture locations, No??

You may get ground heaving conditions by/at the stubs.

BTW, if you have concern, I do not know of any prohibition (NEC) or mfg that says you cannot install exp joints if you want.

John


John
#44387 11/04/04 12:07 AM
Joined: Oct 2004
Posts: 53
I
Member
There will be lantern posts (5' high or so?) every 130'. Since it is underground, it has to be wet rated wire, so I'm not too concerned about any leakage/condensation inside the conduit. Stubs will have to be brought up to the posts, that's correct. Fortunately, the lamps are only 25 w or so, the voltage drop won't be a big factor.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
MarkC10
MarkC10
CA, Inland Empire
Posts: 43
Joined: September 2013
Top Posters(30 Days)
Trumpy 10
Admin 10
Popular Topics(Views)
280,438 Are you busy
213,522 Re: Forum
200,401 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5