Description:
J-Hook: cable support fixture, usually metallic, designed in a “J” shape to hold and suspend cable bundles or innerduct on ceilings, walls, beams, purlins, in raised floors. A removable/reusable clip is typically included to close off the “J” and prevent cables from jumping off the hook during installation or MACs. (Some manufacturers allow for cable ties or hook and loop fasteners instead of clips.) The hook’s wide base and beveled edges prevent damage to cables during installation and provide appropriate bend radius to prevent performance degradation.
Bridle Ring: cable support fixture, usually metallic, designed in a ring shape to hold and suspend cable bundles on ceilings, walls, beams, purlins, in raised floors. The top of the ring will be open to allow insertion of cables without the need to thread them through the ring.
Both options offer a suspension option that typically will require less time and material and have a lower cost than cable trays.
Application:
J-Hooks provide a non-continuous pathway for innerduct and communication and low voltage cables including Category 5E, 6, 6A, 7, coaxial and fiber optic.
Bridle rings provide a non-continuous pathway for communication and low voltage cables and are not recommended for high performance cables (Category 5 and above and fiber optic).
Installation Considerations:
BICSI recommends initial fill rates to be 40% when designing pathways. This partial fill will allow for expansion, moves and changes of your cable infrastructure in the future. Most networks never get smaller, but they will get bigger. You cannot pull new cable in a pathway that is full, and it can be very difficult to run new hooks in a finished building with all the other infrastructure components in the way (HVAC, other cables, lighting, etc.).
The intervals between hangers should not exceed five feet.
Cable sag between hangers should not be more than 12 inches at midspan.
Power and data cables should not be installed in same hanger.
To avoid damage to cable during installation the Maximum Pulling Tension should not be exceeded. This will vary by cable type. For 4 Pair 24-23 AWG UTP this should not exceed 25 pounds force (25 lbf or 110 Newtons).
Common Options:
Bridle Rings:
- with lag screw threading for installation directly into wood
- with threading for use in threaded fasteners (beam clamps, anchors, etc.)
- with loop for use with nail, bolt or other fastener with head
J-Hooks:
- with hammer-on clamp for beam flange
- with screw-on beam clamp
- with angle bracket for anchor or other fastener with head
- with bracket for threaded rod or wire
- with bracket for post attachment
- constructed from Nylon
Popular Manufacturers:
- Cooper B-Line(A division of Eaton)
- Erico Caddy(A division of Pentair)
- Panduit
- Black Box
Related Industry Terms/Acronyms:
- MAC – moves, adds, changes associated with network installs
- Static Load - a load that does not change in weight or position; in other words, it maintains a constant force.
- Plenum - plenum-rated cable has a special insulation that has low-smoke and low-flame characteristics. Plenum rated cable is mandated to be installed in any plenum (air handling space).
- Riser - riser-rated cable will not have the plenum characteristics, so the cost will be lower making it more cost-effective when installing in non-plenum areas (such as vertically between floors – hence “Riser” terminology).
- Cable OD - outside or overall diameter of a cable.
- Bend Radius - the minimum radius a cable can be bent without kinking it, damaging it or shortening its life. When cabling is bent beyond the specified minimum it can cause transmission failures.
- Bat Wing - slang term for a drop wire clip, roughly shaped like a bat wing, used to attach a J-hook or bridle ring to drop wire or threaded rod.
Comparison Chart:
J-Hook Cable Capacity
| J-Hook Diameter | CAT5E | CAT6 | CAT6A | 2 Strand Fiber |
|---|---|---|---|---|
| 3/4" | 16 | 10 | N/A | 16 |
| 1" | 20 | 15 | 10 | 20 |
| 1-5/16" | 50 | 35 | 25 | 50 |
| 2" | 85 | 55 | 35 | 80 |
| 3" | 200 | 150 | 80 | 200 |
| 4" | 315 | 200 | 140 | 300 |
* Capacities are averages for steel hooks and will vary by manufacturer and cable OD. Based on 70% fill rate.
See Also:
Further References:
- BICSI (Building Industry Consulting Services International)
- IEEE (Institute of Electrical and Electronics Engineers, Inc.)
- ISO (International Organization for Standardization)
- TIA (Telecommunications Industry Association)
- ANSI (American National Standards Institute)
- FOA (The Fiber Optic Association)
Associated Videos
Caddy CAT HP J-Hooks
Frequently Asked Questions:
How far should hooks/rings be spaced apart?
A maximum of 60” is recommended, but you may need to decrease that difference if there is excess sag in the bundle. Excess sag (typically 12” or more) will increase tension on the cables and may result in a decrease in performance or even complete failure.
Why are bridle rings not recommended for high performance cables?
The rings have a very narrow base on which the cables will rest. This characteristic will increase tension on the cables which will alter the pair geometry. This may result in cross-talk, decreased performance or even complete failure. (Pair geometry refers to the configuration of conductors within a twisted pair cable - the mated pairs and the number of twists per inch that unite those conductors.)
