Douglas Krantz - Technical Writer - Describing How It Works

Is There a Code that Forbids the use of Tie-Wraps?

By Douglas Krantz | Maintenance

Is There a Code that Forbids the use of Tie-Wraps?


Is There a Code that Forbids the use of Tie-Wraps?


Greetings Douglas,

Although I see a lot of low-voltage technicians running tie-wraps as their main supports, and I suppose NFPA 70 says that listed cable ties can be used, I'm Choosing to run J hooks and bridal rings in situations when fire alarm cables are free aired. Definitely has a cleaner look to it, and I have discovered that tie wrapping to steel joists leads to ground faults.

Low-voltage technicians, here, tend to run wires on the sprinkler pipes and ceiling tile, saying that there's no code for low-voltage. One of my project managers had me do an install with one-hole strap zip ties. At that the time, I was a NICET 1 and I didn't read the code well enough. However, ever since I've chosen to never do that again, even if that means getting fired. Now I wanted to share all that with you, because reading your articles and books and the correspondence has helped me realize these things and influences the way someone installs the systems.

Thank you again for your correspondence and encouragement.

Thank You, BC

This is my perspective on the tie-wrap and other issues you seem to be addressing.

The NEC (NFPA 70) and NFPA 72 are both publications of the National Fire Protection Association, a publishing house, showing the bare minimum standards to have an adequate fire alarm system. Just because something isn't forbidden by the NFPA doesn't mean that using it is the best idea. You can always do better.

When looking at tie-wraps, the writings in these publications don't explicitly reject the use of listed tie-wraps. The writings do, however, require all equipment, including tie-wraps and cables, to be listed.

OK, the tie-wraps, the wire itself, and any other fire alarm equipment is listed as it leaves the factory. However, if something, like the tie-wraps, isn't installed according to the listing by the testing laboratories like UL, ULC, FM, CE, CCC, etc., it's no longer listed.

Always keep in mind, also, the NFPA does not list anything, and the NFPA does not evaluate any testing laboratory. (Read, in the NFPA 72 Appendix, the definition of the word "Approved".)
  • Too much tension on the tie-wrap is a violation of the tie-wrap's listing
  • The insulation on a wire being distorted by a tie-wrap is a violation of the wire's listing
  • Using a tie-wrap to clamp a cable against a sharp metal edge is a violation of both listings

Proper using of tie-wraps in a fire alarm system isn't instinctive. To properly use tie-wraps in a fire alarm installation, the installer has to be very experienced, have the proper training, or both. It is really not very intuitive to use the tie-wraps correctly, and use them according to their listing.

On the other hand, it is far more intuitive to install J-hooks and bridal rings correctly. As a bonus, in later years, changes to the wiring, or additions to the wiring is far easier with J-hooks and bridal rings because they are explicitly designed for these wiring changes.

As far as tying cables to sprinkler systems, the installers need to read up on all the listings, codes, and rules included in the NFPA 13, NFPA 14, and many other publications. The hangers for these systems are listed to carry the weight of the sprinkler system, not the weight of any extra wiring. A hospital I worked at got slammed by CMS (Centers for Medicare and Medicaid Services, commonly just called "Medicare") for tying some power limited (Low Voltage) wiring to sprinkler pipes.

Laying any wires, power limited or otherwise, including fiber optic cables on top of ceiling tiles is a violation of the ceiling tile's listing. The ceiling tiles hanging system is listed to carry the weight of the ceiling tiles, not anything else.

The NFPA 70 and the NFPA 72 doesn't go very far into the requirements of ceiling tiles or sprinkler pipes, but we, as fire alarm system installers, are still required to follow these other listings and codes.

All of this writing is a long-winded way of saying, "I agree with your concerns".



Douglas Krantz

facpdoug@douglaskrantz.com
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