just been cabled

[neoice]

Hi,

Our office of 20 computers has just been cabled. When I was connecting the switch I noticed that the cables to the patch panel have been tied to the 4 way power socket. I have also noticed cat 5e cable routed and clipped on power cable routes.

Is this ok?
will it cause interference?

cheers,

neil

 

[daronwilson]

Yes the securing to a conduit or raceway system is definately a NEC issue, but my issue was more of a theory concern.

Assuming you have power wire in a conduit, the conduit is at ground potential and thus providing a complete (grounded) shield around your AC power, I really don't see the coupling and/or noise taking place at a real noticable level. MANY times we are in PVC conduit in a concrete floor next to AC wiring in PVC. If you look at many floor outlets poured in a slab, the PVC conduits are run right next to each other for 100 feet or more. No shielding, minimal phyisical separation, and the things test ok and run. Plastic partitioned surface raceway is the same, either on the wall or in office furniture. Now...it is possible that the electrical conduit in question was NOT properly bonded and grounded, and as such could carry some current, which could easily couple to the wire strapped to it. If that were the case, it is not a cable/certification issue, but an improper electrical ground that 'caused' your problem.

I sure can't argue with your sucess, but I have a hard time understanding exactly why if you had a passing wire strapped to a metal conduit, you removed it from the conduit, and suddenly the data would flow. I've seen stranger things, just secured it and breathed a sigh of relief that it was working, but left the job not understanding exactly why. I always like to know why

Good Luck!

It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[ANFPS26]

Daron, we always referred to situations like that as "FM". (The second word is "Magic&quot

Jim

 

[daronwilson]

Yup...and it ain't Frequency Modulation.....

It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[shipwright]

So after the Data Cable is installed to "spec" ie.away and not near any power or conduits etc ,what happens when the electrican comes in at a later date and runs his BX cables near ,running with or crossing over our data cables,do we have to go back and move the data cables because he doesn't know the data code , i think not,i know not. Hands up anyone who has'nt seen it, that IT guy in the nice suit put your hand down now and go buy the workers some beer.

 

[naturl]

Being near power is asking for trouble. I had a user in a highrise loose WAN connectivity, Tracing his cable back to the phone closet reveiled where the phone man recently installed a T-1. My cable ran down next to the duplex box that the T-1's power transformer had gotten plugged into. Reroute the cable away from the powermodule {and conduit} any we're surfing dude.

Bob

 

[daronwilson]

SO....your WAN connection ran down next to the duplex power recptacle and worked fine until a T1 got powered up next to it? And you figure the problem was the proximity to the electrical outlet? That doesn't add up for me.

Honestly, if something like moving your wire away from a power module and shielded/grounded metallic conduit restored your connection, I suspect you had a very marginal installation to begin with. What was your headroom in the original installation? Did you test it before relocating the wire?

I'm not advocating co-location with power, I'm merely saying that once it is in a shielded/grounded metal conduit, the power is reasonably contained. I've just not experienced this kind of problems with power, perhaps it is because we're sure to bond/ground everything, or 15 years of doing this isn't long enough to run into much of it.

Regarding the electricians helping us, I'm very familiar and close to that problem. I've taken a lot of time to educate them. Recently I ran all the data and phone cabling in J hooks at the peak of the roof in the attic. The electrican, (MY electrican) came back and ran NM cable right along with it full length of the building for exterior lighting. We talked, I explained, he moved it 4' down away from my stuff.

No simple answer, if moving the wire 2 feet makes it work then I'm all for it. Regarding testing though....if a $6,000 tester fails to show any problem, and a $8 NIC is having trouble with the circuit, at what point to we rely on our testing and equipment? If a $6,000 tester does NOT show that the system is in perfect form according to specs, why the hell are we depending on it? Back to my original stance I think, if your approved/calibrated tester shows the channel to pass with headroom, you have provided a workable wiring solution per the standard for the system installed.

Good Luck!

It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[Servamatic]

Many times testing is done while the building is unoccupied, when the client moves in and has all the lights on, copiers running, printers, and all the other equipment, you may find you have issues, even though it passed a test when installed.

I am not saying it is common to have problems if a line passes the test, but just don't kid yourself into thinking a certification test means ZERO problems with cabling at a later date.

We test to prove to our clients that we care enough to install the very best available and that we will not take short cuts.

Again, I would never consider installing cat 5 or better without certification testing.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[Bobg1]

Daron in naturl's situation, I suspect it was one of those plastic covered transformers/power supply units that was plugged into the recpt. Those things can cause a mess.

 

[Jtodd]

Bospurl:

To address your tester. The DSP-2000 will only certify Catergory 5. I've gotten cables with 'jelly bean' splices to pass Cat 5. You've previously mentioned the NEXT test, but the difference between the Cat 5 and 5e NEXT is significant, and if you're making the move to Cat 6...NEXT is critical and the standard is even higher. Being that Cat 5 is no longer recognized as a standard, I'm not sure why Cat 5 only testers are available still.

Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay