Open Ceiling Cabling 1

[shmoes]

Hey all,

I've pretty familiar with basic network setups hiding stuff in the walls neatly is pretty easy. However I've been given a new project that i've never done before which is to run the network in a ceiling that is open.

After doing some reading i've come to the conclusion that mounting some conduit in the ceiling is the best way to hide the cable. Where i get a little lost is how to deal with the breaks and the locations of the junction boxes.

For this example lets say I have 100' length i have 3 gaps where i would have to run the cable down to the office.


___________ x ___________ x ___________ x ___________


like so .. now at these gaps, should I be terminating all cables at each junction? or should i only terminate the cable that is leaving the conduits and run the other straight through to the next junction.


I guess i have a few more questions for you more experienced guys in this field .. does what i'm saying even make sense? LOL .. is there a better way and do you know where i can find some good reading on it?

Thanks!

~Shmoes

 

[franklin97355]

Try something like this.

http://www.panduit.com/products/browse.asp?classid=82

all cat5/6 runs need to be continuous from the terminal room to the final outlet if possible.

The answer is "42"

 

[robertjo24]

Shmoes,

If you use conduit, add in "LT" type conduit fixtures at the junction points, and run direct circuits to each office. The other cable runs can continue on to their final destination throught the conduit fitting.

I would pull sepparate pull strings to each drop point to help facilitate installations later on.

 

[telecomtekperson]

I agree, make it a continuous run, with no junctions. Imagine you go to a job knowing that the electricians have put in conduit to the cashwrap. You tie your pullstring and cable on to the pull string they left you (if your lucky) and go to the other end and pull. Sounds asy until you realize that you ernt pulling your cable. Just the pull string tied off at the junction box(the first of many) Then, after you actually find all the junctions, you try again, only tofind the cable getting caught on every junction box.

HOMERUNS baby......HOMERUNS.

 

[lopes1211]

What type of space is this? Is it office space with that "industrial look". Is everything else exposed (HVAC, electric, plumbing)? If so, we've found the best solution to strategically hide the cabling as best as possible based on the space using jhooks between joists and carefully planning the cable paths. You're going to use extra cable by not choosing the shortest path rather the most hidden path. (i.e. if there is a hallway along an outside wall with joists running parallel, you can use j-hooks along the joist closest to the windows. No one can see the cable unless they go right up to the wall and look behind the joist). You'll have to be extra clean about your work so it looks good but it's not too hard to hide 90% of your cabling this way. If it is an intentionally exposed ceiling structure as part of the architecture, this may actually be what they are going after rather than a network of conduits.

-CL

 

[TouchToneTommy]

How about a cable tray with conduit stubs from the workstation to the tray?

 

[shmoes]

thanks for the advice guys, i'm still unsure.. I wish i could see something that's already done so i can invision it a bit.

the type of space is an office space as you discribed lopes, everything will be painted the same color .. i'm not sure what a joist is or a cable tray is?

~Shmoes

 

[franklin97355]

i'm not sure what a joist is or a cable tray is

Hire someone to do this one for you. It will save you much grief.

The answer is "42"

 

[shmoes]

One does not learn by getting someone else to do it for them do they.

Hiring someone is not an option because this job is for my employer and they are expecting me to do my best -- and they know I have no prior experience.

~Shmoes

 

[evilcb]

The top two links have diagrams so you can visualise what's needed.
The last link is a general overview of structured cabling.

http://www.marcocableman.co.uk/pdfs/products.pdf

http://electrix.co.uk/english/html/basket_frameset.htm

http://www.netx-datacom.co.uk/theguide.pdf

Remember when pulling cables
1. respect minimum bending radius
2. maximum pulling tension

 

[ats9963]

A well planned and installed cabling job does not have to be hidden, nor should it be painted. In a loft office with everything exposed and painted, you would do best by installing Erico brand of CAT 32 J hooks in a straight line, incorporate 90 degree bends where needed and buying cable a similar color of the area. If exposed cable gets painted, the solvents in the paint can breakdown the insulating jacket and ruin your cable run. With attention to details and being a little fussy about appearance you can do a beautiful job. Of course what ever you do MUST meet local building codes. If conduit is required, it is absolutely best to hire an electrician to install the conduit. The learning curve for proper conduit installation is extreme and can look nasty real easy. Good luck.

 

[daronwilson]

I've never seen a row of J hooks exposed in an office, i suppose that is one way to accomplish it, but i wouldn't consider that a finish installation. If it must be exposed, I have used surface raceway (wiremold, panduit, etc.) or if the customer wants to actually see the wiring, a cable tray (chatsworth, b-line, snaketray, etc.) can be run around the room and neatly handle the bulk of the wiring support.

Not to offend you, but the reason someone suggested you have it done is that it can be a bit complicated if you don't know the work, or the required codes, and in many areas may require a license. I know enough about Linux to work at the command prompt, but I'd never let my employer expect me to build them a server and configure it. It would be a waste of their money and my time when i could find someone experienced to set it up and show me how to run it.

So, conduit. If you do conduit, just throw a junction box in where you want wires to exit out. Depending on how many wires you have, you will need to size the conduit accordingly. The National Electrical Code and other standards can provide you with tables to help you determine the maximum fill. Let's say you have 30 runs, and you are dropping off 10 at each box for example. You may need to start with 2" conduit, but you can reduce the size between the next boxes since you have 20, then reduce again since you have 10. Again, you would probably save time getting some help on this.

Other raceways such as panduit and wiremold are very similar but might be easier for you to work with.

Some basic rules include no splices, don't pull more than 20 pounds of tension on the wire, make sure you observe the bend radius, mark the wires at both ends, etc.

I guess to further suggest a solution for you, i'd need to know how many outlets you are talking about and how long they are. Also, how willing the customer is to have this crap stuck up in plain view.

BTW, I can see the point about painting wires not being a good idea, though I have never seen a failure due to paint degrading the jacket, and I've seen miles of painted cables.

Your mileage may vary.

Daron J. Wilson, RCDD
Solving 'Real World' problems

 

[shmoes]

I know how to work a network, I know how to run cable properly in ceilings and walls. I know how to properly bend and terminate cables. Regarding the help, while i'm not opposed to asking for help and I don't take offense, you have to understand how frugle my boss is. I've already suggested we take lead from our electricians who have done this before. However he'd rather pay me peanuts then pay the electricians wage. To him my time is paid for anyways so he doesn't see the extra time it'll take me as an added expense.. which is why i've come to the best place i know for advice.. it would be more foolish for me to try and do it without previously researching and winging it. the only thing i did take offence to was someones suggestion that my refusal to get an electrician to do it was out of greed, but that is not the case here. If i knew of any local courses here I would be all over it.

Back to my problem of open ceilings, all i really want to know comes back to advice on my original question. Which i think have been answered, as I was not sure about this junction box idea, which has been suggested to me that I do not split them (and i won't) as well as the type of condiut to use, but now that I have some ideas I have something to work with,and I thank you all for that

~Shmoes

 

[skip555]

One does not learn by getting someone else to do it for them do they.

not true at all , when I was starting off I had a guy I could call to help/teach me . there where jobs where I paid him more than I collected but you know what ?

next time I didnt need him I knew how .

 

[shmoes]

Again, that would apply well in a situation where you are a contracted worker as it appears you are, and you will be repeating this job for $ in future. For this scenerio it does not apply.

~Shmoes

 

[franklin97355]

Remember that in some states and localities it is required that to install cable you need to be licensed and have building permits. My state of Oregon being one, if you do the job without permits and licenses you could be required to pay someone to remove it and then start again from scratch.

The answer is "42"

 

[shmoes]

I will check on that, and let my employer know if that is the case. thanks!

~Shmoes

 

[Sunrise05]

Shmoes,
If your employer is frugal as you stated, the conduit thing can get rather expensive. It also limits future moves/adds/changes.
"daronwilson" mentioned cable tray and that may be the way to go. Cablofil makes an excellent tray for open architecture and it is easy to install, as is Snaketray. Each even have a "How to" in their catalog.
You can install conduit from the tray to each station location.
I have used this manner of installation at several jobs with excellent results.

 

[dibthree]

Frugal. My last boss was frugal. And everytime he forced us to cheap out we ended up with a mess.

Do you not have a decent vednor? This is pretty basic cable 101 stuff. There are a bunch of products on the market. If you do not have a good vendor there are a ot out there. Just get them to come in and look at it and bid it for you. Even if you are just going to do it yourself you can use the design they propose. Not that I recommend using a vendor like that. You might actually find that you would rather have them do the work once you get pricing. Most large cable vendors only make about 10% profit. It is worth the extra 10% to let them design, install, and warranty it for 20 years.