atcomsystems.ca/forum
Posted By: sph Grips, strain-reliefs, supports - 11/03/08 07:18 AM
I was wondering how often do you find use for the above? (low voltage applications).
I'm asking because we recently did a wiring job (all Cat6) and the customer insisted on them on all vertical runs and at the horizontal consolidation points on each floor. In my view it was a bit of an overkill.
There were a lot of runs, but their offices spanned only 4 stories, the longest run was barely over 75 feet (wall plate to 110 block) and the wiring was supported in raceway/conduit throughout.
I thought the tensions could be handled very adequately without grips + strain reliefs. These things were not exactly cheap relative to the cost of wire used.
Is there something I am missing here? I just would like to know the memberships' opinions and practices.
Posted By: dagwoodsystems Re: Grips, strain-reliefs, supports - 11/03/08 09:58 AM
The only thing I've used grips for is service drops, i.e. for coax or telephone that's "flown" in from a pole to the structure receiving the service.

I don't know what the job looked like, so I can only guess. If the riser portion was done in nothing but conduit, the I can see how 200 CAT6 cables running 75 feet vertically might want to "slump" or creep downward. The threat of that occurring though, would depend entirely on the way the cable was supported at the conduit exits.

I've also heard riser grips being used maintain a comfortable bend radius around a corners or at the entrance of a data cabinet.

My preference is to use trays, ladder or multiple Caddy type J-hooks and velcro, all of which are acceptable ways to handle these issues. I'll bet that's what you're accustomed to as well. Bottom line? Yeah, it sounds like it may have been a bit overkill. But since that's what the customer wants to brag about on the golf course, I wouldn't argue. Install it and bill accordingly.
Posted By: Touch Tone Tommy Re: Grips, strain-reliefs, supports - 11/03/08 07:06 PM
How about this Vertical Backbone Cable Support from Caddy

[Linked Image from erico.com]
Posted By: Silversam Re: Grips, strain-reliefs, supports - 11/03/08 08:03 PM
Tommy -

That's a pretty good one (Caddy support). I've used it once or twice. Most of the times that we use kellum grips or similar fasteners it's on large count riser cable.

You've got to be careful with Cat 6 and above not to crush the wire with your fasteners - Otherwise you might screw up the certification.

Sam
Posted By: sph Re: Grips, strain-reliefs, supports - 11/04/08 01:58 PM
Tommy, that support looks interesting, I'll keep it in mind. Dagwood, the issue here was indeed strain relief, more than it was support. The MDF (enclosure-mounted) was in the top floor. Each floor (except the top) had an IDF mounted in an enclosure where 110 frames terminate all floor wiring. The longest riser run was less than 50ft - that includes slack that I thought we had arranged rather cleverly in both ends to alleviate strain. The wires themselves had plenty of space within the vertical pipe.
It was more an issue of the IT guy in charge wanting to do everything by the book. The guy is knowledgeable, but he was pretty rigid with this knowledge. He insisted in a max wire fill of 40% even when this necessitated extra raceways to be fitted (don't ask). He then started on the total weight/distance ratios etc etc. Well, they're liquidation/receivership consultants and they probably anticipate a lot of business, who knows. As Silversam said we did end up using conduit-fitting kellems at the MDF and strain reliefs at the IDFs.
Thanks for your considered opinions, keep them coming.
© Sundance Business VOIP Telephone Help