I am running 3" rsc above ground across a 30' creek. I was told I needed a christy box installed on each side of the creek, what are these and how do I install them?

  • 1
    Who told you about the "christy box" requirement? Maybe you need to ask them?
    – Michael Karas
    Jan 26 '20 at 11:07
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    Do you mean that the conduit's buried on either side of a bridging structure, and emerges from underground to travel across the structure?
    – bishop
    Jan 26 '20 at 14:46
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    Is this conduit being run attached to a bridge of some sort, or is there no existing bridging structure in the vicinity of the run? Jan 26 '20 at 15:51
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    Yes, bishop, the 3" sched. 40 pvc is buried in trench at 18", it will rise just before the creek bank, where i was told to install a cristy box or pull box, and span the creek 30-40 ft, with rigid metal conduit.
    – william
    Jan 27 '20 at 2:34
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    Is there a reason you want to span over the creek here instead of going under it? Jan 27 '20 at 4:55

Christy is one of the many companies that make handhole boxes (like a minature manhole) for underground conduit / cable. It gives you access to pull or splice at junction points on an underground cable / conduit rum.

I am going to assume the rigid conduit goes into the bank of the stream on either side and a direct burial cable will go in the pipe, or a direct burial cable will be spliced to something else at those points.

So someone suggested you'll need a handhole at those splice or pull points, which is correct.

(Unrelated to the question, also assuming the cable is supported by a bridge or something because you can't span 30' with unsupported conduit, and that the poster is aware the permitting for things crossing streams can be ridiculously difficult.)

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    I was told I might have to put support structures every ten feet on the span of the rigid metal conduit.
    – william
    Jan 27 '20 at 2:38
  • @william, that's correct, you must support the conduit with a maximum of ten feet bewtween supports. Jan 27 '20 at 22:58

A "christy" box is a semi-buried box that has the cover exposed. Also called a "pull box" or a "quazite box" these are used to start and terminate a cable run outdoors. Usually made from a cement-base compound, they are available from local electrical supply houses.

Why, however, are you wanting to run the line above ground? The line will be vulnerable to anything being carried down the creek. Have you considered having it horizontally bored in?

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