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On a decent quality cable you are unlikely to run into any scenarios in a typical residential or small business install where noise and interference causes a de
by brk 4y ago
On a decent quality cable you are unlikely to run into any scenarios in a typical residential or small business install where noise and interference causes a degradation in throughput.
The balanced signalling used in twisted pair communications is very robust these days, and then you have various protocols on top of that which can handle small errors natively (eg: TCP retransmissions).
It is highly recommended, and often required by code, to keep low voltage and high voltage (high voltage being 120V AC power lines, which really aren't that "high" of a voltage) separated physically. This can be air separation, keep them several inches apart, or conduit separation (don't ever run them in the same conduit). This is mostly a safety issue in the case of insulation breakdown to keep any high voltage leakage from entering the low voltage cable and equipment.
Similarly, things like minimum bend radius, and untwist amount at termination can often be wildly violated with no ill effects. But, it's still best to not temp fate if not needed. Even max cable length can often be exceeded by 20% or more.
- jaclaz 4y ago>It is highly recommended, and often required by code, to keep low voltage and high voltage (high voltage being 120V AC power lines, which really aren't that "high" of a voltage) separated physically. It depends, there are types of data cables certified (insulation above 400 V) to be installed in same conduit as mains wires: https://news.ycombinator.com/item?id=34725851 https://news.ycombinator.com/item?id=34725851
- brk 4y agoUntil you wind up with an AHJ who doesn’t care and requires you to separate the cables.
- jaclaz 4y agoWell, that can happen about almost anything, having data and mains cables separated is anyway a good idea, but (with the correct cables) is not (anymore) against code in many situations.
- brk 4y ago100% agree. My main point is that it is a "just because you can doesn't mean you should" sort of scenario. There are situations where it is allowable, and safe, of course, but it would still generally be considered bad practice unless absolutely necessary.
- mnw21cam 4y agoIt isn't the voltage that causes interference, it's the current. A flowing current creates a magnetic field which can induce a voltage in nearby wires that run parallel. It just happens to be that the wires that carry the highest current are your power lines at high voltage. If you have a wire carrying a very high voltage but no current at all, you shouldn't get any interference from it. Likewise, you could have a low voltage cable carrying lots of current (though why, I'm not sure), and that would cause interference. Your point about code and safety is separate, valid, and very sensible though.
- crote 4y agoLow-voltage and high-voltage wires are not separated for interference but for safety. OPs point is that if a 230V wire somehow got damaged it could end up touching the outside of an Ethernet cable, and if the Ethernet cable is not rated for that it could cause serious damage to the attached equipment. You either need to keep Ethernet away from power, or make power 230V+-tolerant.
- ethbr0 4y agoOr just run power over Ethernet, because no safety best practices survives market ease-of-use pressure. /s