Slashdot Mirror
How a Wiring Rack Should Look
Julie Jacobson writes, "It's so much fun to deride some of the worst home wiring jobs in existence. But once in awhile, we should salute some of the cleanest, most perfectly labeled cabling jobs in U.S. homes. At the recent CEDIA Expo, the association for home-technology integrators handed out awards for the Best Dressed Systems, each featuring miles of cable, hundreds of connectors, tons of steel, and a clean aesthetic that could make the most finicky designer swoon. Show them to your own installer for inspiration."
Found an old picture of one of the messiest racks I have ever seen. Personally I think a messy NOC should be a punishable offense. I can't tell you how many times some stupid blip in the system is caused by a dangling wire with so much other wiring hanging on it that it gets pulled from the panel. Nothing like a 4am pager going off, coming into work and finding the root cause of the problem is the idiots that wired the rack. Kudos to those who do it right.
Funnypics
http://www.talkaboutcedia.com.nyud.net:8090/articl e/10397/ and here's another mirror
... there is such a thing as carrying it too far. I'm reminded of the tale of the junior sysadmin who proudly showed the senior sysadmin the cabinet he'd just wired up. Very neat, very pretty.
...)
The senior sysadmin looked at it thoughtfully, then flipped a single switch. Every server in the cabinet went down. Yup: every server had its entire power source coming from a single rail, instead of having the two redundant inputs coming from different rails.
Where I work, every cable to every server in the machine room is labelled at both ends. The patch panels are also labelled with the address of the other end of the cable. Makes troubleshooting network problems a lot simpler (and that's important when you're talking over 200 servers on the floor
When they wired their mainframe, they spent about $2000 for a bunch of bix panels.
When it was my turn to do the same job, I took $5.00 and went to the hardware store, I picked up a 1ft by 4fr plywood scrap and bought a box of finishing nails and brought that in the office (the canadian head-office of a fortune 500 company, btw) and started hammering away neat rows of nails to which I soldered wires from a 100 pair cable we ran between two floors.
On hearing the hammering, the boss of the other department (who happenned to pass by by chance) came to have a peek, and he sees me hammering and soldering and asks me "what are you doing???"
- I'm doing a patchboard for the serial lines.
- Why don't you use a BIX board like we did in the plant?
- Because yours cost $2000 and mine only $5.00.
He left without saying a word.
Here is a picture of a site in Dallas, TX. This picture belongs to a HUGE telecom company. A baby bell if you will. ;) How they maintain this I will never know.
http://www.waystupid.com/item-378.htm
What is more amazing is that after several attempts by staffers, the management refuses to let people clean this up. And they show this to prospective customers on a daily basis!!!
Mike @ The Geek Pub. Let's Make Stuff!
In our computer room I just provide plenty of wire management, a wide assortment of cable lengths, and a picture of the wedgie I gave the last admin who kludged something 'for testing' and left it that way for months.
"Also, the editor put an incorrect link in."
Guess he got his wires crossed ...
I'd like to be a judge on that panel. I'd love to give out awards for the best rack.
What? Wiring? What are you talking about? Oh...
"All great wisdom is contained in .signature files"
While viewing the article, my wife overheard me saying, "Ooh, nice rack on that one.
Warning: The intelligence of this post may be larger than it appears.
I didn't Read either of TFA, because they seem to be slashdotted at the moment.
However, after years and years of living, I can tell you that "if a job is worth doing, it is worth doing well" is just not true. Sometimes doing a job "good enough" is more than enough. It might get torn down next week. If you wash the windows "OK", that is probably good enough, they'll be dirty again soon enough.
It all depends on what you are doing. Building a house? Do it well. Wiring a computer cabinet? Pfft - make it good enought for a few years. It will change. RS-232, thin-wire, thick-wire, 10BaseT, Cat 3, Cat 5, Cat 5e... Fibre... whatever.
If you can do a 90% job for half the cost you will have enough left over to do another 90% job of something twice as good 4 years from now.
Maybe. YMMV.
This issue is a bit more complicated than you think.
I honestly don't think that it was much of a problem for RS232 communication (i.e. high-voltage, relatively low frequency).
The Raven
To a limited extent, I agree.
Neatness is one thing, but those examples just look like an advertising photo for nylon wire ties. I mean, they look nice now, but what happens when you need to move one of those connections around, say from one port to another?
You'd have to cut 50 different ties, and all the wires are cut to such precise lengths, you'd probably end up having to splice some sort of nasty extender in there (adding a significant insertion loss due to the connectors or splice). It would be a total mess. Having everything wired in drum-tight may look nice, but it's a bitch later on. Something that has more "drip loops" before all the wires get bundled up into single harnesses may not look quite as polished initially, but it's far easier to work on down the road.
I've worked on audio systems like this, and it always strikes me as something that you'd do if you were a contractor working on a one-shot job, something where you want to impress the client and justify your fee, with no real thought to maintenance later.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
...Can one create a duplicate within the same submission.
... sometimes it has a tendency to get to your head. You didn't get your EE degree for hammering some nails to string RS-232C, any more than a doctor gets their degree to treat a common cold in a healthy 8-year old. In the same fashion, I didn't get my CS degree to write Swing UIs. Did our educations tangentially cover these things? Yep, they did, but they're a) not our core competencies and b) can be done by someone who is literate and capable of following a simple single sheet of instructions.
Why are our degrees important? Well, one thing they let us do is properly identify edge cases. A self taught programmer implementing a Swing UI with a sorted combobox might decide to use a bubblesort on it, which would work fine through testing right until it got to a customer who put a couple hundred items in it, when the application would just start to unexpectedly hang. The doctor hopefully catches that 1 kid out of 10,000 who doesn't actually have the cold and needs treatment within the next 48 hours to save his life. And you, as an electrical engineer, identify when impedence would be an issue.
Ah, but here's the rub: edge cases are edge cases for a reason, and purported experts who cry wolf regarding the edge cases get ignored by a public which sees solutions which work perfectly for 2.5% of the price. And, as several folks have pointed out, you're crying wolf here. The reason the solution appears to work isn't because the grandparent was ignorant of impedence, its because its just physically impossible for that to be a problem for that device.
Or, as I learned in Engineering school (in tech writing, of all places): "You're going to graduate with a degree from one of the best schools in the country, and you'll be working your first job with tech-school grads who have 15 years of experience, and in your first two weeks one of them is going to say something you learned in school is wrong. You might disagree, perhaps vehemently. But before you voice your disagreement, figure out exactly why he thinks his way will work, because odds are it will. Remember: he's worked there for 15 years and hasn't blown it yet, or he wouldn't still be there."
Help poke pirates in the eyepatch, arr.
I know this is not going to be a popular opinion but..
Tightly bound cable bundles at the rack are NOT helping anyone but the anal person looking at the pretty pictures. Try troubleshooting or replacing a wire in that bundle at the rack. A rack is a dynamic environment, that is why there are jacks there! If it was not meant to be dynamic, why even use jacks at the rack? Just hard wire everything. If your rack is attached to the floor, movement and cable chafing is not a problem either. If you have to spend more then 5 minutes to get the bundle the way it looked before you replaced a wire at the rack level, you are wasting every ones time including your own to get it to look absolutely perfect. There is NOTHING wrong from a technical standpoint by using the plain old cable management hooks on the front of a typical rack that the cables route through, each wire does not need to be zip tied or Velcro every few inches and each wire spreading off of the bundle with a cable tie for each one, in fact, you can cross over the width of a typical 19 inch rack without the need for any additional bundling other then standard wire management trays and hooks. Side rack mounting depends on type of management you have for that, I've seen some better then others.
Like I said, my opinion is not going to be a popular one but can someone give me a technical reason why every rj45 plug in something like a 24 port blade needs to tied individually or even in groups of two? Is that "unsafe"? Is it a hazard in your environment? If so, what the hell is going on in your equipment room and why do you not have a door on your rack? Is it harder to track down then a huge bundle 20 deep and zip tied to 10ft lbs every 3 inches?
Oddly enough, I've seen many installations where the rack looked pristine but the out of sight areas or covered parts for the actual runs like under floor or overhead in partially covered trays or inside the rack vertical sections looked like spaghetti. If your goal is neatness and you justify the clean rack area for some technical reason, what is your excuse for the other areas that are out of normal sight looking like crap, do those technical reasons for a pristine rack not apply to areas others can not easily see? In order to get the rack to look nice, the extra cabling is balled up and hidden elsewhere. It does not make sense.
For reference, I do neat work now and I've had to replace and re bundle cables and wires inside nuclear reactor instrumentation control panels and rack mounted electronic instrumentation shelves using nylon string and shellac so I am very familiar with the concept and the goals of proper wire management.
If a job's not worth doing, it's not worth doing right.
Check out this crazy yellow one. And it's yellow! :)
From AQFL.
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
That's why they invented PATCH PANELS - the wiring coming into/out of the rack is bundled, and goes to the patch panel - NEVER to an item in the rack - in fact, even wiring intra rack goes via a panel
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso