Shielding Ethernet Cables

Yes it can be installed inside a length of steel conduit,  go for steel as its far more effective than aluminium,   to be most effective the conduit will need to be earthed.

Your 30cm separation is not correct,    EN 50174-2 allow 20cm for unscreened power & unscreened ethernet.    If the ethernet is screened (Cat6A or Cat7) the distance can be reduced to 5cm.    But if its unavoidable & the distance is short it is not so bad to run together,  better still with Cat6A or Cat7.

Mike, is copper also good for shielding use?

enjoy

ken

Hi Ken, the low 50Hz frequencies such as we are dealing with in this application,  high magnetic permeability is required & the low carbon steel used for electrical conduit & trucking has good field attenuation.   Non-magnetic materials like copper (or aluminium) have little effect on low Hz fields.  Copper is better suited to RF 

Mike, many thanks.

is it obvious whether the mains cable or the ethernet cable should be so treated? the OP asks about shielding the ethernet cable. in that case whynot use a shielded ethernet cable with suitable precautions to prevent the ground problem that may become an issue with shielded cables?

enjoy

ken

Mike-B posted:

Hi Ken, the low 50Hz frequencies such as we are dealing with in this application,  high magnetic permeability is required & the low carbon steel used for electrical conduit & trucking has good field attenuation.   Non-magnetic materials like copper (or aluminium) have little effect on low Hz fields.  Copper is better suited to RF 

When I installed CAT6 cable in my home, I routed the cable where possible in disused 22mm copper central heating tubing.  The tubes had previously been connected to a back boiler in the the living room, so the final cable drop into the living room was very easy and neat. Separation between the two cables I installed was ensured by running one in the flow tube, the other in the return.

EN 50174-2 requires  20cm between unscreened 240v x 50Hz power & unscreened ethernet,  5cm between unscreened power & screened ethernet & 2cm between screened power & unscreened ethernet.  This indicates a screened power cable is the more effective.      But there is also a significant improvement over all unscreened cables by using screened ethernet,  so your suggestion is worth consideration.   

fatcat posted:................   I installed was ensured by running one in the flow tube, the other in the return.

 

A very good solution,  a gift from the gods.    

john s posted:

I'm about to have a dedicated mains supply installed, which is good news, but physical constraints mean that it will have to be close to and parallel with my ethernet cable from NAS to Uniti. I've read several posts about separating the two  by 30cms but I doubt I can do that - is it feasible to shield the ethernet cable some way (e.g. inside a metal pipe)?  Has anyone had any experience of this?

I really wouldn't worry about -I read the very latest iteration of EN 50174-2 specification on this has been simplified and if the mains power lead(s) do not exceed 32 amps and within a single phase, there is no strong source of EMI nearby (i.e. typical home environment as opposed to a data centre) and the application is not affected by no separation (like ethernet) - then no separation is required between mains  and IT/ethernet wiring. 

However if you had high level of EMI in your mains such as from power line adapters then the recommendation is to apply separation between the source of EMI (mains cable) and IT cables... and those distances are defined by power, construction and shielding type.

If you are that worried about noise and electromagnetic coupling best use fibre - this is what I would typically do professionally.

Simon

Useful Simon,  did you find a www copy of  latest EN 50174-2 spec. or did it require purchase (?)      But whatever,  the previous rev allowed for no separation over the final 15m of horizontal run;  that 15m covers most (all) domestic installs.  

No I cheated..   I found the Norwegian equivalents which refer to and quote the current EN standards and their recent changes...

This all appears to be a bit too compiled. How about just going optical: Relatively cheep. Easy to run cables as they are small and flexible. No interference. Total electrical isolation.

 Just need to find an economical way to hire the kit to do the cable terminations? Could be worth a try?

Paul

No reason not go optical,  but no reason to give up on ethernet either.   Its not complicated & much of this forum chat about noise & crosstalk is unwarranted in most situations IMO.  

If you use sheilded cat 5e or cat6 you should have more than enought EMI protection - both will run 1gbs easilty

Yes. I sort of agree. I am running cat6 on the 5 meter run and cat5e for the patch cables.  Should all be ok.

But how can I know if I have an EMI issue or not? Any way this can be measured?

Dia duit Paul,   if your ethernet is not close to & running parallel to power cables - & I'm talking closer than 20cm for numbers of metres - & if the power cables are carrying less than 32 amps,  then you don't have EMI problems.   You can't measure it without some expensive equipment anyhow.     If you are still loosing sleep over a section where the power & ethernet are running close for a few metres,  replace the cable with Cat6A.  

Mike-B posted:

No reason not go optical,  but no reason to give up on ethernet either.   Its not complicated & much of this forum chat about noise & crosstalk is unwarranted in most situations IMO.  

Of course optical (1000Base SX/LX etc)  supports Ethernet just as twisted pair does (100/1000BaseT ) , it's just a different physical presentation. Certainly a long run in an electrically noisy environment optical would make sense, but again sharp bends and twists are to be avoided. There are also minimal distances for optical, so extremely short distances are not supported. Also with Naim equipment a seperate transceiver is required thereby potentially introducing noise back into the twisted copper.

Perhaps the Statement streamer will have fibre GBIC connectors?

Simon

Thanks - some very interesting replies here. I'm using Cat 6 so I'm going to leave things as they are as the cables will only be close together for a short run. If I notice anything significant I'll post again.