I have seen a few questions regarding how close ethernet cables can be to power cables without a significant impact on the data. For example:
Can I run CAT5/6 cables parallel to electrical cables?
Is "don't mix data and power cables" and "don't loop power cables" still valid nowadays?
It seems that the short answer is basically that they should be separated generously.
However in my case I will be running them in "separate conduits", which will be ordinary PEX tubing (underground). Furthermore, the power in this case will be a weak (high gauge) extension cord. The application is that I am running these cables to some security cameras which are 500-600ft distance away, and I don't think the cameras draw a lot of power. At least, it wouldn't be as much as present in the main line from the street.
The first question I linked has a comment which cites a standard:
800.133(A)(2) states that Communications wires and cables shall be separated by at least 50mm (2 in.) from conductors of any electrical
light, power, Class 1 non-power-limited fire alarm or medium-power
network-powered broadband communications circuits. Exceptions are if
separate raceways or conduit are used for separating the
communications cables/wires from the power conductors.
Does this mean, in my case I can just put them in different PEX tubes and not worry about how close they are- they can be right next to each other? There will be no loops, just a straight run (with a few curves).
It matters to me in this case because it would affect the width of the trench I am to dig.
I wonder if my question is more appropriate for some kind of electronics forum but I appreciate any guidance.
Thanks
Best Answer
You're not allowed to mix low-voltage and mains wiring in any way, shape or form in the same cables, conduits or raceways. The reason is safety: the data cables may not threaten the power cables, but melting or damage of the power cables absolutely could cross mains "hot" voltages onto your data cables.
This is only allowed if the data cables and everything the data cables connect to is also inside Class 1 wiring methods. Such as 24V latching-relay-based lighting controls. Or 0-10V dimming controls run in the same conduit as mains. Or ethernet used as SCADA between mains control equipment all mounted in Class 1 enclosures.
What's not allowed is running an ethernet through a mains conduit, having the ethernet land at an Ethernet cover plate, and then proceed via Ethernet cable which is decidedly not a class 1 wiring method to a local PC, where it enters a data port not hardened for mains power.
Anyway, as far as mains is concerned, "separate conduit and you're good". If your conduit is metal, you probably really are good. If it's plastic, then you might have signal interference if the signal is susceptible to 60Hz or whatever line noise is on the mains line; however the Electrical Code really doesn't care about that. These days most electronic signaling is so high frequency that it seems unlikely that old mains line noise could have much effect.