CAT6 wiring next to 240V AC

[canastasiou6]

Hello! I ran into a really serious problem while wiring my already built house. So, I want the telephony DSL wire to go to my modem and 2 CAT6 (unshielded) wires to come through the same line to route and wire my PC with one and use the other for my powerline adapter. So the problem is that 3 wires won't fit (2 should though) in the tubes in the wall. My father told me that there is an electricity (240V AC) and larger tube that should help to wire one of the2 ethernet wires as the tubes (telephony + electricity) go to the same place. Shall we route the one through the electrical wires? I told my father that it wouldn't be a good idea due to interference (he has little knowledge on this subject). Though I wanted to confirm if I would run into problems doing that due to electrical interference.

Thanks in advance

[mariushm]

You could just get shielded ethernet cable but even with regular ethernet cable you'll probably be fine routing the cable along the AC cables. The AC noise would be low frequency and the wires inside are twisted to reduce interference, and you have multiple layers of insulation on the ethernet cable. By design, there's signal transformers  on network card and switches/routers/whatever so even if live AC would get into the ethernet cable, your devices won't die or kill your pc.

 

[canastasiou6]

8 hours ago, mariushm said:

You could just get shielded ethernet cable but even with regular ethernet cable you'll probably be fine routing the cable along the AC cables. The AC noise would be low frequency and the wires inside are twisted to reduce interference, and you have multiple layers of insulation on the ethernet cable. By design, there's signal transformers  on network card and switches/routers/whatever so even if live AC would get into the ethernet cable, your devices won't die or kill your pc.

 

My CAT6 has no insulation or shielding take a look at the attached photo

[mariushm]

The wire itself has insulation on it, the pvc/pet/whatever colored material ... if there was no insulation the wires would touch each other.  The insulation is dielectric, it doesn't conduct electricity.

Two wires at a time are twisted together and they're separated by the other pairs by that middle + or x  channel usually made of plastic ... well, a proper cat6a cable would have such a plastic core to separate the twisted pairs, yours may not have it if it's only cat6.

Then, the sleeve of the ethernet cable is a second level of insulation ... it's not shielding because shielding would be an aluminum or copper foil wrapped around the pairs of wires under the sleeve, or a mesh of aluminum/steel/copper wires wrapping the pairs of wires.

Either way... like i said, there's two layers of insulation protecting the internal copper wires (or aluminum if CCA cable) from mains.

 

 

[ShearMe]

Putting anything in a conduit with electrical wires that isn't another electrical wire is.... generally a bad idea. Please don't do this.

[canastasiou6]

On 5/22/2020 at 7:15 AM, ShearMe said:

Putting anything in a conduit with electrical wires that isn't another electrical wire is.... generally a bad idea. Please don't do this.

I know but there's no other way around this. Is there any specific reason that u have in mind towards why not to do this? I think I will do it today and test it

[Falcon1986]

11 hours ago, canastasiou6 said:

I know but there's no other way around this. Is there any specific reason that u have in mind towards why not to do this? I think I will do it today and test it

Never run high voltage wires next to low voltage wires for extended lengths. If a stray nail, screw or  staple punctures your electrical wire parallel to your ethernet cable, you’re going to be sending 110-220V straight to your connected network devices and computers!

 

And because you’ll be cramming 2 ethernet cables through this conduit (which makes everything closer to the electrical wire), you might have a hard time pulling them through. If your electrical wire is stripped of its insulation from any sharp edge within the conduit, someone’s life will be in danger.

 

A safer alternative would be to run the ethernet cables parallel to your telephone or coaxial TV cabling.

[mariushm]

Ethernet network cards have isolation transformers on them, isolating all signal pairs from the network card.

On onboard network cards, the isolation transformer is often hidden inside the actual connector.

 

Transformer on network card:

 

 

Transformer hidden inside the RJ45 connector  : https://www.digikey.com/product-detail/en/abracon-llc/ARJ-196/535-13148-ND/5430433

 

 

 

 

Explanation on stack exchange for the reason (simply because among first search results) hardware - What is the purpose of an Ethernet magnetic transformer, and how are they used? - Network Engineering Stack Exchange

 

Quote

The primary purpose is isolation. Typically they are also used as part of the signal conditioning, turning a pair of single ended drives into a differential signal on transmit and establishing the correct common mode voltage for the receiver on receive. For this reason the device-side of the transformers is usually center-tapped.

 

Isolation is a very good idea on communications systems that are linking lots of hardware over a wide area. You don't want fault current/voltages in from faults in the mains wiring or devices to spread through your communications wiring.

There are basically two options for isolation, opto and transformer. Transformer isolation has a couple of major advantages. Firstly the signal power passes through the transformer which means you don't need to get a power supply to the "isolated" side of the barrier. Secondly transformers are very good at generating and receiving differential signals while providing high common mode rejection, this makes them a good combination with twisted pair wiring. Thirdly it is easier to design transformers for high frequency (aka high speed) than optocouplers.

 

Transformer coupling does have some downsides, transformers don't work at DC and small transformers that work well at high frequencies don't work well at low frequencies but this is easilly dealt with through line coding schemes that avoid low frequencies.

 

If you shove AC on the ethernet cable, yeah, if you're unluckly you may damage the transformer on the ethernet card (transformer's wires are super thin so they'll probably melt) and maybe even get the network card to die but your computer won't be live and there's no risk of you getting shocked by electricity.

[ShearMe]

On 5/24/2020 at 3:14 AM, canastasiou6 said:

I know but there's no other way around this. Is there any specific reason that u have in mind towards why not to do this? I think I will do it today and test it

Just as @Falcon1986 suggested, the risk is mainly in future accidents. The ethernet might function just fine, but you're creating a potential liability during future construction or fire. Here in the West we have building codes which try to eliminate danger when things go wrong. Putting low voltage and high voltage wiring together is a big no-no.

 

You said you have a small conduit and a big conduit right? Can you move the electrical to the small conduit? That'd leave the bigger conduit open for any low voltage wiring.