Cat 5, Rj45 Question.

K2

We were asked to troubleshoot motor controls to about 100 automatic sunshades in a very large commercial establishment. After looking at it we determined that at least most of the problem is in the cat 5 and rj45 connections. These connections are all daisy chained from one source running through 25 splitters into phone cord and then two more splitters. The rj45 connections were site made and is is obvious that some are intermittent or not connecting at all. We are not low volt guys and will turn down this service call but would like to say something intelligent when we meet with the owners on monday. Any help would be appreciated.. Thanks...

mdshunk

What's to say, except for the fact that you have determined that there were poor field terminations made. Someone with a cable qualifier needs to check the whole system and reterminate where necessary.

K2

So would you say daisy chaining from a single point would be acceptable if the connections are made?? Seems to me, ( not knowing ), counting on 50
rj45's and 25 splitters could be a crap shoot under the best conditions..

gallerytungsten

Daisy chaining with that many connections sounds like a recipe for trouble. Any one faulty connection brings down all the ones after it.

A star topology is much better, as it will be far easier to find any faults.

K2

Yeah thanks. I was just thinking that it has 7 zones feeding from 14 20 amp breakers. Seems like at the very least one cat 5 to each zone would make more sense. ... I'll have to google "star topology".

mdshunk

I suppose it depends on what the manufacturer of the shade controls says (Lutron?). I've only ever seen the common bus shade controls daisy chained, but then again, I've never seen as many in one place as you're dealing with. A home run for each certainly makes no sense, but zones certainly makes great sense from a troubleshooting standpoint. Would be funny to see punchdown blocks in an electrical closet marked "shade controls".

Greg C

If it was Lutron shades, they used the wrong wire for control. Lutron does not spec cat-5, but uses its own wire for LV motors and control. It is a bundle of a 16-2 and 18-5 shielded.

signatown

The most common mistakes people make is to perform another trade jobs without having the proper qualifications.

If you want to take over this job because you want to make a few dollars, be careful!!! It might bite back to you.

You will be surprise how many calls I receive from other trade contractors asking for help for this type of issues.

At the end you might open a can of worms. I suggest you to subcontract an specialist on this trade.

It seem that this type of job is more than a star topology problem. You might consider the FR interference, macros sync issues, and 120 volt power share issues. The list could go to a mile long.

Please, don't get offended. This is just my opinion.

K2

We walked. I have some hubell certifications but i don't like little wires i can't see anyway. Thanks..