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I have the following cables between two machines:

  • 380V 3-phase power cable
  • 24V signal cable
  • EtherCAT cable

I would like to create an interface using a modular connector such as the one in the picture below.

My question is it safe to put all these cables in a single connector (the cheaper option) or should I put the 380V cable in its own connector (the more expensive option)?

enter image description here

rickiepimpim
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  • There are precedents for high power and signal in a single connector ... most car chargers. So it can be done with appropriate care. Whether that's the right answer for you, I can't say. –  Jul 03 '20 at 20:23
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    @BrianDrummond I would expect that the signals in a car charger are treated as live and fully isolated. – SomeoneSomewhereSupportsMonica Jul 03 '20 at 20:55
  • @SomeoneSomewhereSupportsMonica That would count as part of "appropriate care". Which may overall be more expensive than simply separating the connectors. –  Jul 03 '20 at 20:59
  • @BrianDrummond , SomeoneSomewhereSupportsMonica Thanks for your replies. The isolation in these industrial connectors is quite sufficient. I guess we will just have to test it after assembling everything. – rickiepimpim Jul 03 '20 at 21:15

1 Answers1

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Is it safe? Yes, as each cable has the proper insulation for the voltage it carries. The question is; Do the power cables inject noise into your Ethernet cable? If it is a shielded CAT-6 it should be fine. While 50/60 HZ power is ignored by the high frequency Ethernet runs at, it can pick up HF noise injected into the power lines, including your 24 volt power feed.

So the issue is do you have to use noise filters on your AC and DC power feeds to keep from inducing noise into your Ethernet feed? If you're powering motors, contactors, solenoids and other inductive devices they can and will induce noise-burst into local signal cables. Most data downloads are checked for errors and corrected, but streaming video screams in at full speed with no error checking.

So without noise filters on your AC and DC power feeds you should be able to download data and code with no problems, but streaming video could be full of glitches and pixelation if your power feeds are noisy.

For this reason Ethernet is normally run at least a yard/meter from power feeds.

Neil_UK
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  • Thanks @Sparky256. The Ethercat cable connects a PLC to an Ethercat coupler and all motors are controlled using VFDs fitted with noise filters. There are no other inductive devices. In any case I'll go with a shielded ethercat cable. – rickiepimpim Jul 03 '20 at 21:27