CAT-5E FTP not properly terminated?

[sven]

Hello,

 

Just had 48 new cat-5e network cables installed in the new library refurb. The people doing the cabling have used cat-5e FTP (foil twisted pair or shielded cabling) but have not terminated the shielding at either end using a non shielded patch panel and non shielded modules by the desks. Has anyone had any experience with interference issues when having a similar setup? If all this cabling needs to be redone, then I'm going to have to raise this with the site manager pretty soon.

 

Any suggestions welcome!

[glen_j]

i wouldn't see it as a problem, most cat5e installs are using utp (unshielded twisted pair)

[pantscat]

What did the original spec say?

 

If they were supposed to install FTP then they'll need to do it again and properly...

[localzuk]

If the FTP hasn't been grounded, then it won't be doing anything useful. However, as far as I'm aware, it won't be doing anything negative either.

 

If FTP was specified, I would be asking for the correct patch panels to be provided and installed.

[sven]

I never got to see the original spec, as this was all completed by the site manager. I'm not bothered if it's shielded or unshielded so long as it works. I have read previously that if shielded cable is not terminated correctly, it can create something like a faraday cage through the cable. With no earth at either end, I assume this can cause interference.

 

I've literally been up to look at the work today, and seen on the back of the patch panels that the earth inside the cat-5 is just loose and not connected to anything. It could be a case of they just used shielded cable and never had any intention of using shielded wall floor ports of patch panels. I don't want to tell the site manager anything unless it's going to be a problem. If it's not going to cause any issues, then I'll just leave it as it is.

[pete]

There's no reason to spec FTP if you're not going to earth it at one end. Ask to see the spec sheet.

 

They've either overcharged you (FTP costs circa ~£30 more than UTP) for no reason or they've failed to do the job correctly.

 

Stop letting your site manager make decisions on cable infrastructure without oversight from IT.

[sven]

There's no reason to spec FTP if you're not going to earth it at one end. Ask to see the spec sheet.

 

They've either overcharged you (FTP costs circa ~£30 more than UTP) for no reason or they've failed to do the job correctly.

 

Stop letting your site manager make decisions on cable infrastructure without oversight from IT.

 

It's not like I've just sat back and let him do this. I was not aware of this happening, otherwise I would have questioned it. As far as I was told, they were installed 48 ports and 2 x 24 port patch panels with unshielded cat5. I was just at a loss as to why the bothered using FTP cable and then didn't terminate it correctly.

 

Thanks for the input anyway. I'll feed this back to our site manager.

[plexer]

Whoever made the original decision to exclude IT from the process of having structured cabling installed needs to be shown the error of there ways, do you have any lift shafts or basement spaces?

 

Ben

[Jaco45er]

Hi Sven

 

FTP should be terminated to create a Faraday cage, that's the idea, to leak unwanted noise to earth. Mind you, if your comms cab isn't earthed (most don't get earthed), then FTP is useless. As others have mentioned, was FTP specified for a reason? I.E. does the cable route through an area that has a high risk of electromagnetic interference (EMI)? Like a boiler room where data cables run close to with KVA cables? If so,then FTP is needed to protect the cable. However, I have lost count of how many schools we have cabled since 2000, and not once have we used FTP (well, unless its Cat6a links). We do use it a lot though in Factories where 440V machines are used, its perfect for that environment.

 

Also, as mentioned before, FTP is more expensive

 

That said, I have come across many a network with an un-terminated earth FTP cables, and never seen an issue.

 

Hope this helps

[Duke5A]

Whoever made the original decision to exclude IT from the process of having structured cabling installed needs to be shown the error of there ways, do you have any lift shafts or basement spaces?

 

Ben

 

Note to self, don't cross plexer.

 

In all seriousness though, I've never seen shielded cabling installed in a school environment either; not even in relatively big districts (10,000 kids or so).

[Koldov]

Note to self, don't cross plexer.

 

Why, do you think he is asking for lift shafts and basement spaces to dump the bodies of whoever didn't include I.T....?

 

Actually, we've just had an outbuilding cabled, nothing big just a couple of data ports so the electricians did them as they were pulling other cables as well. I have to crimp ends on the switch/comms room end and plug them in to the correct switch ports, as they have done the faceplates in the dado of the outbuilding.

I went to check they were being done, so I could get my end finished and tested and interestingly enough, the sparky was pulling back the foil sheilding and clipping off what I presume were earth wires, before clipping the remaining wires into the colour coded backplate of the socket...

 

Kol.

Edited March 25, 2013 by Koldov

[sven]

Hi Sven

 

FTP should be terminated to create a Faraday cage, that's the idea, to leak unwanted noise to earth. Mind you, if your comms cab isn't earthed (most don't get earthed), then FTP is useless. As others have mentioned, was FTP specified for a reason? I.E. does the cable route through an area that has a high risk of electromagnetic interference (EMI)? Like a boiler room where data cables run close to with KVA cables? If so,then FTP is needed to protect the cable. However, I have lost count of how many schools we have cabled since 2000, and not once have we used FTP (well, unless its Cat6a links). We do use it a lot though in Factories where 440V machines are used, its perfect for that environment.

 

Also, as mentioned before, FTP is more expensive

 

That said, I have come across many a network with an un-terminated earth FTP cables, and never seen an issue.

 

Hope this helps

 

 

Very helpful thanks!