Running Ethernet (Cat 6 UTP) alongside AC Power Cables - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 07:32:28 am
content: I realise it goes against best practice when it comes to network cabling (to run it parallel alongside power cabling) due to AC coupling, however I've come across a situation at home where I can either:i. Run it alongside 20 amp (240v) AC power cables for a distance of no more than 2 metres (power and ethernet within their own separate plastic conduits) and have the installation look neat and tidy, or,ii. Run the ethernet cabling via an indirect route, avoiding power cabling, but have the installation look untidy and messy.The cable I'm using is Clipsal unshielded solid core Cat 6. The entire cable run (from device to switch) would be no longer than 25 metres (with only 1-2 metres actually running alongside power cabling). Signalling rate will be 100Mbps and the data is non-critical so a few re-transmitted frames every so often won't cause problems. I'm also using proper enterprise-grade Cisco switches.In reality, will this cause any issues in this circumstance? Will the error rate still be low enough not to worry about?

author: kripton2035
author_rank: Super Contributor
timestamp: February 09, 2016, 07:50:44 am
content: we had a problem once ago on a customer site where the cat6 cable was not far enough (ca 1 meter) from a neon lighttraffic was slowed from more than 50% ...so stay away from ac cables, but also from lights with ac supply.

author: Ian.M
author_rank: Super Contributor
timestamp: February 09, 2016, 07:59:41 am
content: Can you slip some hollow shielding braid over the Ethernet cable for the critical 2m and ground it?Gas discharge lighting is a special case. The tube has a negative resistance region, and even with a passive magnetic ballast or transformer, HF oscillation is a possibility. Also anything with a cheap electronic ballast can be a severe source of EMI.

author: AndyC_772
author_rank: Super Contributor
timestamp: February 09, 2016, 08:01:35 am
content: Purely in terms of signal integrity, you'll probably be fine. Ethernet is pretty robust.On the other hand, if your installation is such that someone could one day simultaneously put a drill through both Ethernet and power cables, then it's probably a bad idea.

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 08:04:40 am
content: Quote from: Ian.M on February 09, 2016, 07:59:41 amI could. I have the option of running STP with the drain wire connected to the device chassis (ground). Just extra cost involved.Quote from: AndyC_772 on February 09, 2016, 08:01:35 amYeah those are my thoughts. I've seen gigabit ethernet work over some pretty crappy cable in dodgy installs without problems. I'm only asking for 100Mbps, could probably even configure it to run at 10Mbps. It's really low throughput data anyway.As for the other thing, there is next to no chance it would happen.

author: Towger
author_rank: Super Contributor
timestamp: February 09, 2016, 08:05:50 am
content: Option: IWhile always best practice and there will be cases which proves it correct, the reality there is a 99.99% chance you will have no problem.

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 08:08:02 am
content: Quote from: Towger on February 09, 2016, 08:05:50 amI'm leaning towards it. Worst case if it causes issues, I can always re-do it.

author: tautech
author_rank: Super Contributor
timestamp: February 09, 2016, 08:08:21 am
content: I've got a 4m section of a 20+m run of Cat 5 bundled with mains, alarm and phone with no significant impact on data throughput but no doubt there is some.The LAN "just" manages any errors and connection to printers, internet, other PCs and a NAS all work fine.1G LAN.

author: Ian.M
author_rank: Super Contributor
timestamp: February 09, 2016, 08:14:32 am
content: Even 'attack by drill' shouldn't be a major issue unless the switch or the device have POE capability. RJ45 Ethernet ports are supposed to have 2KV rated isolation transformers, so for damage to occur the drill would have to short two different wires in the Ethernet cable to different wires in the mains cable. Add a grounded shielding braid and the chances of that happening before the breaker trips are negligible.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 09, 2016, 08:19:17 am
content: You aren't doing anything thousands of people haven't done before.And with no perceptible problem. Pull in ordinary UTP and get on with your life.We are assuming you are using the Cat cable for conventional digital network communication.If you are using it for some other oddball application, it requires more discussion.

author: nowlan
author_rank: Frequent Contributor
timestamp: February 09, 2016, 08:20:49 am
content: *cough*http://www.acma.gov.au/Industry/Telco/Infrastructure/Cabling-rules/cabling-separation-from-hazardsDont mix them. Better dont nail any data cables without a license.

author: kripton2035
author_rank: Super Contributor
timestamp: February 09, 2016, 08:21:53 am
content: FYI it's forbidden in france to build like that : mains cannot be in the same hole than network (and low voltages cables phone etc)

author: Muttley Snickers
author_rank: Unknown
timestamp: February 09, 2016, 08:22:12 am
content: Snip: Removed Quote.Under AUS & NZ wiring rules this practice is completely illegal and may be punishable by a delicate slap on the wrist for those that aren't registered but for those of us that are licensed and registered cablers it would result in a public hanging.

author: Mr.B
author_rank: Unknown
timestamp: February 09, 2016, 08:38:20 am
content: Quote from: Muttley Snickers on February 09, 2016, 08:22:12 amSorry, but please cite the regulation here...We regularly run Cat6 STP in the same cable trunking as a 400v supply and even some VSD supplies.Sometimes over as much as 30 metres.We don't have issues and I am certainly not aware of any flash over isolation issues covered by legislation.

author: Muttley Snickers
author_rank: Unknown
timestamp: February 09, 2016, 08:49:38 am
content: Yes nice take it out of context, if you read the post I quoted it mentions other services, there are mandatory separation rules, in addition I'm about to remove tautechs quote and notified him to do the same.

author: Ian.M
author_rank: Super Contributor
timestamp: February 09, 2016, 08:50:00 am
content: So every desk with a non-segregated cable management tray is illegal?What about filtered power-strips with Ethernet and phone protection and less than 150mm separation?Phone cabling is a special case because it connects to the PSTN and a fault to mains can cause significant infrastructure damage, so I'd always advise respecting the separation standards for it. but if it isn't a fixed installation, unless your local regs have Draconian scope, chances are it doesn't fall under them.

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 08:55:07 am
content: Quote from: Richard Crowley on February 09, 2016, 08:19:17 amCorrect, just bog-standard Ethernet for data logging purposes. Nothing unusual or proprietary.Quote from: nowlan on February 09, 2016, 08:20:49 amI don't want to start a licencing debate (as far as anyone is concerned, I'm appropriately qualified for such works). I was just asking about the "real world" consequences of doing so. Icouldrun them within the same conduit, but I'll do the 'responsible' thing and run a separate conduit, appropriately labelled as "Data" to avoid any confusion. All I have to do is make sure it's not "capableof being connected to the telecommunications network" and basically I can do as I please. (I also don't plan on using nails.)

author: tautech
author_rank: Super Contributor
timestamp: February 09, 2016, 09:00:51 am
content: Quote from: Muttley Snickers on February 09, 2016, 08:49:38 amI'll take the slap on the wristand it's an installation that's worked for ~20 yrs.It's installed on an exterior overhead galv steel RHS (grounded of course) link from my dwelling to my workshop.

author: dfmischler
author_rank: Frequent Contributor
timestamp: February 09, 2016, 09:10:27 am
content: Actual data:Power and Data Separation Test Results... (pdf 10 pages)

author: Kjelt
author_rank: Super Contributor
timestamp: February 09, 2016, 09:25:33 am
content: To be sure you should use STP and use on both sides a earth grounded NIC so the switches should be earth grounded and have ground shielding. That is how 99,9% of the datacenters in the world do it

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 09:32:41 am
content: Quote from: dfmischler on February 09, 2016, 09:10:27 amGold. Thanks mate. Although they made one mistake in that document... there is no such thing as Cat 6e. After Cat 6, it's Cat 6A.I'll install it parallel to start and post diagnostics data from my Fluke network tester when I get the chance.

author: tooki
author_rank: Super Contributor
timestamp: February 09, 2016, 12:36:15 pm
content: Use shielded cable, with shielded jacks, and a shielded patch cord on one end, and you should be just fine.

author: Brumby
author_rank: Unknown
timestamp: February 09, 2016, 01:04:33 pm
content: How about running the cable down 2m of metallic curtain rod?

author: nctnico
author_rank: Super Contributor
timestamp: February 09, 2016, 02:54:06 pm
content: Quote from: Halcyon on February 09, 2016, 07:32:28 amJust install it like this and you'll be fine!

author: PE1RKI
author_rank: Regular Contributor
timestamp: February 09, 2016, 05:24:42 pm
content: today i extended a 12 volt ac doorbell line with cheap with cat5e cable over a length of 10 meters besides 400 volt cables.i wonder if that is allowed..

author: kripton2035
author_rank: Super Contributor
timestamp: February 09, 2016, 06:09:04 pm
content: no it's not allowed, but it depends on each country and their regulationsin france I know it's not allowed to mix low and high voltage cables in the same sheath

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 09, 2016, 06:36:00 pm
content: @Halcyon asked about "running alongside" and specifically about inductively-coupled interference.We assumed (perhaps incorrectly?) that @Halcyon was NOT talking about running the UTP cable through the SAME duct/pipe/conduit as mains power wiring.Running high-voltage and low-voltage cable through the SAME conduit is illegal everywhere AFAIK (or should be).Nobody is recommending running HV and LV cabling through the same duct/pipe/conduit.However, as for inductively-coupled interference, since BOTH the "transmitter" (the mains cabling) and the "receiver" (the UTP network cable) are BALANCED, and since the operating frequencies are many orders of magnitude apart, I would expect no practical interference from ordinary mains-frequency induced current.OTOH, if the mains power is feeding some really noisy load, that is a different matter which should probably be addressed at the load itself.

author: Halcyon
author_rank: Unknown
timestamp: February 09, 2016, 06:43:09 pm
content: Quote from: Richard Crowley on February 09, 2016, 06:36:00 pmCorrect. I did mention two seperate conduits, one for power, the other for data. They just happen to be running alongside each other for a short distance.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 09, 2016, 06:47:59 pm
content: Quote from: Halcyon on February 09, 2016, 06:43:09 pmYes, you did, and I missed it. Sorry.

author: PE1RKI
author_rank: Regular Contributor
timestamp: February 09, 2016, 10:31:42 pm
content: when i came to the building the 12 volt ac line was already mixed with the 400v cables, i just extended this a bit further.i will lookup the rules for my country for this and let the owner know.

author: XOIIO
author_rank: Super Contributor
timestamp: February 09, 2016, 10:59:29 pm
content: Quote from: PE1RKI on February 09, 2016, 05:24:42 pmLol, probably not the best, but hey if you get a leftover roll of cat5/6, it is handy stuff.I have ethernet and an extension cord running through the drop ceiling to my power rack, about two or 3 meters, with the last meter or so having them zip tied side by side, in the ceiling they are just sort of tossed up there, so there's a lot more cable length, and I didn't notice any effect on my upload/download speeds. This is only 120v though.

author: station240
author_rank: Unknown
timestamp: February 09, 2016, 11:03:52 pm
content: I've heard a story of a petrol station with attached diner where any electrical failure, would take out a network card. At one stage it was several times a month, and this was in the days of 50 ohm coax and 10mb/s.Diner would make a lot of milkshakes, hence their mixers used to blow up from overuse. This send huge voltage spikes down the power cables.Now whoever had installed the network cabling had cable tied it to the power cables. Everything from 2m IEC leads to big 3 phase cables between the switchboards.In Industrial settings where your stuff is protected against overvoltage cable seperation isn't such an issue (or sometimes even possible).

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 09, 2016, 11:46:14 pm
content: Modern network cabling is fully balanced, and transformer isolated on top of that.You can't get much better than that for rejecting common-mode noise, especially at such low frequencies as power mains (50-60Hz)I remember back in the early days of Ethernet when 10BASE5 "thicknet" coaxial cable came with markings on the side where you should use the special drill to install a "vampire tap" to run an RG58 "thin-net" coax cable off to the AUI interface which then connected to your computer.

author: rrinker
author_rank: Super Contributor
timestamp: February 10, 2016, 02:58:00 am
content: I remember when thinnet was all the rage (who didn't have a sculpture of T connectors and terminators on their desk?). We had one client who had two buildings, separated by their private drive - so they just dug a trench, and ran come coax in a conduit across to the other building to continue the network. All well and good, but any time there was a thunderstorm in the area, they would blow the first 2 or 3 network cards on either side of the driveway.

author: Galenbo
author_rank: Super Contributor
timestamp: February 11, 2016, 08:52:42 am
content: Quote from: Halcyon on February 09, 2016, 06:43:09 pm1) Witch 230V AC do you mean? For a light bulb or to feed a noisy servo drive?2) We had problems in an industrial environment, when a motor was shut down due to overcurrent, the network went out too.We accused the network cable that was running several meters close to the ac, but before removing/rerouting it, we plugged in a temporary one, far away from everything.Network went still out. It seemed to be the network-connected-devices that were infuenced, not the network cable.