In the postings about chain link fences, Don made a mention about expansion joints, and it got me to thinking (I know that's a dangerous proposition with me).

Here's the situation- it is a common practice in this area to run schedule 40 pvc along the frame under a mobile home for the feeder supplying the home. Some of these runs can be 50 to 60 feet long. It can get 90 degrees in the summer and as cold as -20 to -30 in the winter for a temperature swing of 110 to 120 degrees. I've never seen an expansion fitting installed in this case

In the example above, the nipple coming down from the panel cannot move & the conduit emerging from the ground into an LB is secured.

Does this installation need an expansion fitiing?

Tom,
Yes that installation does require an expansion joint. The rule would require an expanison joint for any conduit over 10' long with a 65° change in temperature. A 125° change would require an expansion joint for a 5' run.
don

In support of Don

The reference to the 2002 NEC is 352.44 and 352.44 Table A. For those who might want the code reference.

Pierre