Support of RMC

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solarservant

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Colorado
I'm trying to determine if a run of 5" RMC can be supported every 20' or 10' in accordance with 344.30(B). It is approximately 80 feet in total length, with a single 90º sweep in the middle. Do each of the lengths on either side of the sweep count as "straight" - thus allowing me to use Table 344.30(B)(2) - or is the whole thing a single non-straight run (thus requiring support every 10 feet). (Note: I'd prefer to support it every 10', but need a convincing argument to make this happen!).

Also, does a transition from the RMC to LFMC count as a "termination" in regards to securing the RMC within 3' of this point in accordance with 344.30(A)(1)?

Long time lurker, first time poster, thanks!
 
In my opinion you can use the 20' support rule on each side of the 90.

Yes the transition to the flex is a conduit termination for the rigid conduit.
 
Be sure the wall is strong enough to support the weight. I'm sure I can't even pick up a stick of 5" RMC.

I recall a job at a factory where we supported 4 inch EMT every 10 feet, used strut and clamps to anchor. At each end, we had straps every 4 feet or so. A few hangers started moving when we pulled wire. We had to add extra support.
 
jmellc said:
Be sure the wall is strong enough to support the weight. I'm sure I can't even pick up a stick of 5" RMC.

I recall a job at a factory where we supported 4 inch EMT every 10 feet, used strut and clamps to anchor. At each end, we had straps every 4 feet or so. A few hangers started moving when we pulled wire. We had to add extra support.
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You mean #10 x 1" screws driven into 1/4 x 1" plastic wedge anchors aren't going work for this size of pipe?:weeping:





:D
 
kwired said:
You mean #10 x 1" screws driven into 1/4 x 1" plastic wedge anchors aren't going work for this size of pipe?:weeping:





:D
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:D:D
No, we used 3/8 wedge anchors on the poured cinder block wall at the end of the run. Standard thick strut anchored to wall and 4 inch strut straps. All well and good til near the end of the pull. Then as we hit the 1st 90, pipe started slipping through strut straps. We already had struts about every 4 feet, but added 3 more, then resumed pull.
 
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