CharlieWayne said:
What's MMV mean? Just out of couristy do you know why they disallow zip ties? Anything to do with then dry and become brittle?
I know the J Hooks you guys are talking about and they just scream $$ to the power of 4. Hahha, well I'm sure their not outrageous I try to use materials that are abundant for price and supply reasons.
How about P-Clamps? You can buy them almost anywhere, you want the one with rubber or plastic coating, come in many sizes being he wants to run many Different runs, can buy bags in bulks.
There's multiple reasons brought up by AHJ's, all of which I can agree with. Many of the same arguments can be had for velcro. In order:
1. Nylon dries out over time...even opened bags of ty-raps become "stale" if you have them out in the open and exposed. I can't explain it to a non-trade experience, but they lose their tensile strength. Even the UV rated ones dry out. They have a finite shelf life. Ever jostle a ty-rap after it's been installed for a year or two and gone through thermal cycles?
2. The tensile strength of ty-raps is around 50# on the tie. When you start considering some of the bundles that get supported by loops, hooks, straps, etc. you're well within the threshold.
3. They are not rated or listed for supporting horizontal cable runs. While many disagree, ty-raps are for cable management. Yes, I've been guilty of using them to hang a cable or piece of flex on something like a chain link fence for a short span, but that's it.
4. The AHJ's do not like them if there is a fire. The FD tends to pull down ceilings and finishes to locate and fight fires. Ty-raps easily melt far below the cable or substrate's fire rating. This can lead to entanglement issues. The AHJ's cite the same reason why the code books specifically call out for wiring methods to have their own independent method of support, same above drop/false ceilings and why strapping to other materials/pipes is also not allowed.
5. People don't select the right ty-rap for the application many times. How many people use regular plastic ones outside? How many use non-plenum ty-raps in plenum spaces? How many times are they used in areas/locations where stainless banding should be used?
Personally, when pulling cable that is rated for data, the largest issue is going to bearing point in relation to the cable bundle and weight over time. This is why I don't like people using plumbing J-hooks or similar, but the larger issue (sorry Pete) is when you read the code book is clear as day: NOT LISTED FOR USE AND APPLICATION. It may work, but in my case as a pro, I can't pick up plumbing fittings, bushings or the like and use them for my application. Same reason why they make sweeps, LB's and other fittings for pulling cable but you don't use a plumbing 90 on conduit.
P clips are very labor intensive. There are applications, such as running exposed cabling on something like a pole building or I've used them on mini-storage units with camera cabling. Look at the cost of the largest size, $1 a fastener, plus screw and labor is going to add up just as quick as other methods. For that matter, I'd rather use something like drive rings or bridle rings (assuming no data runs, but strictly LV cable). If I'm going to deal with screws and the like, I might as well use D-rings for the amount of labor involved.
