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Authoritative Souce for Cabling Don'ts ??? 4

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Oct 21, 1999
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In our organization (3000+PCs) most floors and buildings were wired by 'in house' talent, in many cases with in-wall wiring extended all the way to the PC, and excess length folded like rope, with kinks in the ends, rather than terminating in jack, with an appropriate length flexible drop cable to the PC.
In many other cases, I've found a wall jack a yard or two from a PC, with a 30 foot drop cable coiled into a donut, with additional length wound serpentine around the toroid core formed by the coiled cable. I'm trying to get these practices stopped and fixed, but my experience and knowledge isn't sufficient - they want WRITTEN documentation where it says not to do these things. Now that they've upgrading the Network from 100BaseT to Gigabit, these wiring gaffes are starting to cause real problems.

The only sources I've found using Google I've found mentions a mininum 1" or 2" bend radius in cables (says nothing about making toroids out of them), and only that kinking cables permanently damages them - not that it harms network performance, etc. Last week I was updating software on some PCs, and one was VERY slow across the network - workers near it mentioned that it is always slow, and that when one of them is working on that PC, ALL of the PCs get slow. This was the unit with the toroidal drop cable. The one in the cubicle next to it had the tightly kinked in-wall cable connected to the PC.

I'm challenged with finding an authoritative source that says these are bad practices, and what the results are likely to be. Just telling them that understanding electricity and electronics make is obvious isn't enough.
To me this is like expecting a Driving manual to have a section where it tells you not to drive off bridges, into wall, or into other cars. Can anyone provide me some ammo in this discussion ?


Fred Wagner

 
Brian - that site is for training and certifying people to do it right - I'd have to buy the book or CD for $99 to see if is has a list of thing you should NOT do!
Thanks anyway !

Fred Wagner

 
You stated that the work was and is being done by 'in house' talent.

They are not covered by any rules except for the ones YOU give them. A simple way would be to require anyone doing cabling to take a certification class from someone like Leviton, ICC, etc.

Good Luck

Has been in the cabling business for about twenty years and is now the Sr PM for a cabling company located in the Los Angeles area.
Also a General Class Amatuer Radio Operator.
 
I believe it would be 99 dollars well spent. BICSI has good reasons why they recommend what they do . Our local Graybar rep set us up with a one hour demonstration from a BICSI certified RCDD that was really eye opening for me and my team.
 
1. No gorilla pull strength - 25 lb max pull strength for 4-pair CAT rated cable. Otherwise use mfg rating.
2. Max bend Communications cable
a. UTP mfg(1.0") Rule of Thumb (4x OD)
b. FTP mfg(2.28") Rule of Thumb (8x OD)
c. STP mfg(1.0") Rule of Thumb (8x OD)
d. RG58 mfg(1.2") Rule of Thumb (6x OD)
e. RG59 mfg(1.5") Rule of Thumb (6x OD)
f. RG6 mfg(1.65") Rule of Thumb (6x OD)
g. simplex fiber (1) mfg(1.2") Rule of Thumb (10x OD)
h. duplex fiber zip mfg(1.0-1.5") Rule of Thumb (10x OD)
i. 2 fiber round mfg(1.8-1.9") Rule of Thumb (10x OD)
j. 4 fiber round mfg(1.9-2.0") Rule of Thumb (10x OD)
k. 6 fiber round mfg(2.0-2.1") Rule of Thumb (10x OD)
3.Conduit fill
1 cable - 53% of Conduit ID
2 cables - 31%
3+ cables - 40%
4.Conduit Bend
-up to 2" 6X ID of conduit
-larger than 2" 10x ID of conduit


Regards
Peter Buitenhek
ProfitDeveloper.com
 
Sounds like you have a BIG MESS.

The proper thing to do is to fix all the problems to a level where they will pass cat5e on a certification scanner like a Fluke DTX . With 3k PCs this will be expensive.

To get management to understand the problem you could look at the error counts on your switches (hopefully managed!) and then get a contractor to come in and run a certification scanner on those drops and fix them.

With the size of your network it might be worth giving Fluke a call. If they think they can smell a sale $$$ they sometimes send reps out with their advanced equipment for demos and troubleshooting.
 
BICSI is by far the best resource on cabling practices. It sounds like a lot of what you are seeing would give any good cable guy fits. Afraid to ask what you have seen in the ceiling, and that can be as important.

If you are looking for some free standards, try looking at websites for IEEE, or any of the other Electronics/Engineering standards group.

I once had a customer ask, and argue about, the standards for fiber installation. He wanted to know why I couldn't just switch the fibers behind a patch panel, instead of him rearranging the connectors in a duplex clip. Seriously.

Good luck, and let us know how it goes.

matt
 
something that large you probably should have a RCDD on staff or one available on a part time basis as a consultant
 
Fred we have around 6000 network devices here we take care of and install more every day. The last 2 months we have been averaging pulling in 11,000 feet a week. None of my guys had any experience pulling and installing cable. This is not their fault if their boss (whoever that may be) let's them pull cables in a substandard method. If they don't know how, they should be taught.

I have purchased 5 (so far) BICSI manuals and train my guys how to do it right. If it's not, then it's their fault because I have taught them how to. I do 2 training sessions a year to help them keep up with changes in technology and let them know what to expect. I have had our fire Marshall's office sit in during the fire wall penetrations instructions. I got him into it I think and he started bringing in movies (of unsafe and unprotected) buildings that have burned down. "Amazing what a free box lunch and a Coke can do... "

So i think this is something that should be addressed with their boss, supervisor, director whoever, and have them to do it right. Also remember these are "standards" not codes.

On more note here. Should someone at your place of business be interested in a BICSI manual to get started, I highly recommend the new "Information transport systems installation guide". It's just a later model of the Telecommunications cabling installation manual.



Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison

For the best response to a question, read faq690-6594


 
Thanks to everyone for their suggestions and info. I looked in the back pages of this forum, found a reference to Cabling: The Complete Guide to Network Wiring, by Groth and McBee - went to our public library web site, found it in stock, and walked over and checked it out. Much the same info as you've posted. What I need to do, and will do, is take a digital camera and take photos of some of the bad practices, and attach them to quotes from the specs, illustrating what spec is broken - like not FOLDING horizontal cable that is run all the way to the PC, because the tight kink permanently damages the cable. Not organizing excess drop cable into a hank, pressing it tight so the ends have a 0.5" curve radius, and securing it with a Wire Twistie. Not coiling excess drop cable into a nice neat roll about 4" in diameter, and then securing the roll by using it as a toroid core and winding still more cable serpentine-fashion through the core. fortunately this is not real common, but there were examples of all three of these in one of our buildings, people commented that 'that PC is always slow', and that, whenever somebody uses that PC, the whole building gets slow..... Duh ! I have to convince my Desktop Support people that when things like this are found, then need to be fixed! They're defending the practice, saying they've always done it this way! It might have worked at 10BaseT, and not been too terrible at 100BaseT, but as they're upgrading the PCs and routers to Gigabit, it's turning out to be TERRIBLE!

Fred Wagner

 
I feel you pain Fred. When our network guys started bumping up everything to Gig, they were surprised how well it went. Some were on the verge of the limitations (around 300 feet) and were a bit flaky, but the majority swapped over with no problems. If you are going to start photo documentation, then here are few things to look for.

The "book" recommends no loops. Like i stated above the cables are not to run over 285'. This leaves a 10 foot patch cable to the device and a 5' in the telecommunication room. Under 300 feet. With Gigabit Ethernet they should be running a good cable. Cat 5 will be iffy at best. I run the Cat5 E (big E or rated for 350 MHz.) Also the cables are only going to be as good as what they are terminated with. So they should also be using jacks, patch panels, and patch cables rated for the same. With this in place your life will be much easier. They are marked on these so you should be able to see the rating at a glance.

If you need any more help with this post it. These guys here do good work and can help.

Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison

For the best response to a question, read faq690-6594


 
I liked your idea on the fire marshall, mikey. Great idea, and it doesn't hurt to have a good relationship in the inspection department!

And a * for remembering the sometimes forgotten patch cord. That has tripped me up more than once, and definitely slowed down everything.

"Rock bottom prices on high speed data cables . . ." straight from 1995! LOL
 
I can rememeber one occasion (oh about 10 yrs ago) where we had bundles of cat 5 wires tiewrapped into nice neat bundles and we were seeing lots of collisions on the network...cut the tiewraps and the collisions went away

Learned a lession from that one

Norm
 
Tell them that they can start fixing them like you said, or you will be submitting a quote for rewiring the entire system to management because the current practices have made the system sub-standard, and will effect performance of the network because of this sub-standard work. Let them know you can only think of one area to cut costs in order to pay for the outside contractor to re-wire the system. Then do the wink, and the making the gun thing with your hand and index finger n pull the trigger, and tell them to get moving on that because if you have to explain how to do their jobs again it will be to their replacements.

Now if they do not know how, then you should be farming this out anyway, and if they need help to learn they should ask, and submit a budget request for the training materials, or instruction they need.

 
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