Jim Katen Posted January 1, 2002 Report Share Posted January 1, 2002 Scanning the chart referenced, you only need expansion joints in lengths of conduit over 25 feet. I don't see much electrical conduit over 25 feet in residential construction. The other place you might see them is where a service lateral comes out of the ground and up into a meter can. If the conduit settles in the trench, it's nice to have some slack to prevent it from pulling the can off the wall. Quote Link to comment Share on other sites More sharing options...
hausdok Posted July 15, 2011 Report Share Posted July 15, 2011 Click to Enlarge 72.12 KB Click to Enlarge 54.91 KB Click to Enlarge 59.4 KB Many thanks to Jim Simmons (User name Mr. Electric) for this contribution. Quote Link to comment Share on other sites More sharing options...
Les Posted July 15, 2011 Report Share Posted July 15, 2011 Must be same guy was in my neighborhood. Everyone went berserk when I called this out! Click to Enlarge 40.23 KB Click to Enlarge 47.2 KB Quote Link to comment Share on other sites More sharing options...
rkenney Posted July 15, 2011 Report Share Posted July 15, 2011 Nice pictures, at the risk of sounding stupid, care to elaborate? Quote Link to comment Share on other sites More sharing options...
ghentjr Posted July 15, 2011 Report Share Posted July 15, 2011 Nice pictures, at the risk of sounding stupid, care to elaborate? I won't "elaborate", but a picture is worth a thousand words. Quote Link to comment Share on other sites More sharing options...
John Kogel Posted July 16, 2011 Report Share Posted July 16, 2011 Nice pictures, at the risk of sounding stupid, care to elaborate? I'll give it a try:The electrical conduit in the first pic should have an expansion joint or two so that that plastic can expand and contract without exposing the cable. It looks like it has pulled loose at a union that might have been poorly glued or not glued. It needs better support as well, more clamps. The flexible conduit is not rated for that usage and it is susceptible to damage, like a kid spinning through there on a bike could catch a pedal on it. Quote Link to comment Share on other sites More sharing options...
Inspectorjoe Posted July 16, 2011 Report Share Posted July 16, 2011 I'll admit, I didn't know expansion joints existed, let alone being required. You learn something new every day. http://www.carlon.com/Installation_Trai ... SEXPJT.pdf Quote Link to comment Share on other sites More sharing options...
resqman Posted July 16, 2011 Report Share Posted July 16, 2011 Scanning the chart referenced, you only need expansion joints in lengths of conduit over 25 feet. I don't see much electrical conduit over 25 feet in residential construction. Quote Link to comment Share on other sites More sharing options...
Ben H Posted July 16, 2011 Report Share Posted July 16, 2011 I can't recall ever seeing one. Quote Link to comment Share on other sites More sharing options...
John Kogel Posted July 18, 2011 Report Share Posted July 18, 2011 Warning, Jim K has traveled back to Dec 31, 2001 and has been bumped to the first reply position on this thread! With his knowledge of the events of the last 10 years, there's no telling what he will do in 2002. [?] Jim sent a telepathic message re: expansion joints on service laterals. Here's an example of a need for an expansion joint between the panel and the ground, a distance of only about 3 feet. The smaller conduit to the cable box has also dropped several inches. Click to Enlarge 47.8 KB Quote Link to comment Share on other sites More sharing options...
Erby Posted July 18, 2011 Report Share Posted July 18, 2011 Don't need an expansion joint there, John. They just needed to install it right. See it quite a bit around here with houses built on hillsides. Electricians get a pretty penny for fixing it. Especially when there's a ton of water in the conduit. - Quote Link to comment Share on other sites More sharing options...
Bill Kibbel Posted July 18, 2011 Report Share Posted July 18, 2011 Warning, Jim K has traveled back to Dec 31, 2001 and has been bumped to the first reply position on this thread! With his knowledge of the events of the last 10 years, there's no telling what he will do in 2002. [?] Jim sent a telepathic message re: expansion joints on service laterals. Here's an example of a need for an expansion joint between the panel and the ground, a distance of only about 3 feet. The smaller conduit to the cable box has also dropped several inches. Click to Enlarge 47.8 KB I thought that a slip joint for ground movement is something different than an expansion fitting. Quote Link to comment Share on other sites More sharing options...
Douglas Hansen Posted July 18, 2011 Report Share Posted July 18, 2011 I thought that a slip joint for ground movement is something different than an expansion fitting. I think you are correct. An expansion joint is listed for a predictable amount of expansion/contraction between two fixed points. Frost heave or ground settlement are less predictable. What Carlon calls a "slip meter riser" is longer than an expansion joint. I've been confused by this, in part because the informational note for 300.5(J) mentions "expansion joints" and isn't really correlated to the UL standards for such products. http://www.carlon.com/Master%20Catalog/ ... ochure.pdf I like the idea of the product in the link above because it will also function as a drain. Douglas Hansen Quote Link to comment Share on other sites More sharing options...
Erby Posted July 18, 2011 Report Share Posted July 18, 2011 Doug, your "slip meter riser" could really solve a lot of problems around here, IF they would have installed them. Unfortunately, I've NEVER seen one around here, though I've seen a LOT of conduit pulled apart and/or broken due to ground movement. - Quote Link to comment Share on other sites More sharing options...
Marc Posted July 18, 2011 Report Share Posted July 18, 2011 Doug, your "slip meter riser" could really solve a lot of problems around here, IF they would have installed them. Unfortunately, I've NEVER seen one around here, though I've seen a LOT of conduit pulled apart and/or broken due to ground movement. Now we have something to recommend for that. The service conduit rising from the earth to the meter box is broken or discontinuous, likely because of settlement of the soil around it. This leaves the service conductors within it exposed and unprotected. An electrician should install a "slip meter riser" on this conduit. Sounds simple but it's likely a lot of work, and expensive. Marc Quote Link to comment Share on other sites More sharing options...
Greg Booth Posted July 18, 2011 Report Share Posted July 18, 2011 The undewrwriter inspectors working in my area have been calling for meter slip joints for the past 10 years or so.........they're seen everywhere here. Greg Quote Link to comment Share on other sites More sharing options...
Douglas Hansen Posted July 18, 2011 Report Share Posted July 18, 2011 The undewrwriter inspectors working in my area have been calling for meter slip joints for the past 10 years or so.........they're seen everywhere here. Greg Greg - When you run into one of these again, could you take a picture to share with us? It certainly seems like a product we should be using out here, though I have never seen it. I have a project right now with two conduits going from a meter pedestal down to two buildings that are about 25 feet lower in elevation. It seems that these slip joints would solve the problem of water rising in the conduits at the buildings. The other ways we deal with the water problem are to have a drain/pull box outside the downhill structure, or to put an upside down wye in the riser. Thanks Douglas Hansen Quote Link to comment Share on other sites More sharing options...
Greg Booth Posted July 19, 2011 Report Share Posted July 19, 2011 I'll post a pic tomorrow. ........Greg Quote Link to comment Share on other sites More sharing options...
fyrmnk Posted July 19, 2011 Report Share Posted July 19, 2011 It's not just the conduit settling leaving the conductors exposed, it's also the potential issue in the can if they didn't leave enough slack to accomodate the movement. Quote Link to comment Share on other sites More sharing options...
Chad Fabry Posted July 19, 2011 Report Share Posted July 19, 2011 The undewrwriter inspectors working in my area have been calling for meter slip joints for the past 10 years or so.........they're seen everywhere here. Here, the utility decides if they're necessary. All RG&E customers have them and almost no Niagara Mohawk customers have them. Quote Link to comment Share on other sites More sharing options...
Greg Booth Posted July 19, 2011 Report Share Posted July 19, 2011 Click to Enlarge 35.66 KB This is an older style slip-joint-installed about 10 years ago ..........Greg Quote Link to comment Share on other sites More sharing options...
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