sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring J-Hooks

What is the correct distance between j-hook to j-hook when installing them in a newly constructed office building?

Is there a certain distance between them that will effect the way cable lays between them?

I have an upcoming new construction job, THAT MUST use these. I dont want to underpurchase or overpurchase them.

Thankx

Check your BIcsi TIA 568 ( not to be confused with the cabling method 568A or B). I believe it is still 48-60 inches. This covers Cat3-5. Haven't seen anything changing for Cat 6.

I have always used a 48 inch spacing for J-hooks.
Local codes might apply also.

Rich

usually your OK if spacing is equal to the trusses or joists, about 4 feet. Those plastic hangers (plenum) that wrap aound the cables and lock work real well too.

[This message has been edited by bikechuck (edited February 01, 2005).]

48 inches works well because the bundles can stay neat with only a few tie wraps/ velcro straps, and there won't be a dip in the cable.

I read something a while back (BICSI material, perhaps?), that said for data use the supports should not be equally spaced along the whole route...in other words, vary your distances between to cut down on signal degradation. I've seen jobs done with J-hooks anywhere from 4'-8' apart.

Regardless of what staqndards there are, The one that overrides and supersedes all is the NEC Article 300. Cables must me attached and secured to the building structure at 4 foot intervals.

In our area, it's usually the local electrical inspector who ultimately mandates this spacing. According to the National Electrical Code, it's 42".

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Ed
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How come there's always enough time to go back and fix it a second time?

Article 300 does not apply to low voltage and communications wiring covered by article 800 and beyond unless it is specifically referenced. Read from the beginning of the book. There is nothing in the NEC that stipulates support distances for communications cables. This is a design and installation issue.

If your electrical inspector has something to say about it he must cite the article in the NEC (or local ammendment) that he believes is not being followed. He can't just make things up or decide he doesn't like something.

-Hal

Yikes! We just go along with the inspector using Article 300 for non-metalic cable as a reference. We don't push the limits; we may need their help later. Usually, we just assume that we should give them what they expect rather than to engage in a battle of the wits!

I agree with you that for everything in the code book, there is a contradiction elsewhere. We used to laugh about that when I was an electrician many, many, many years ago.

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Ed
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How come there's always enough time to go back and fix it a second time?