8 conductor cable, not plugged into anything nor terminated. Thank you!

EDIT: Just to clarify, I'd like to use it as an Ethernet cable and it is not currently being used for anything, so I want to see if I can just crimp Ethernet connector to it (and find the other end) if it'll work as an Ethernet cable without causing any problems.

I believe that jacket reads "24 AWG C(ETL) US LISTED 2003548 TYPE CMR/MPR FT4 BKC 118163 25BCB FEET ETL." Photos below:

Photo 1

Photo 2

Photo 3

  • It's an ethernet-type cable. But that doesn't necessarily mean it's being used for ethernet. – Simon B May 27 at 19:18
  • Thanks. I edited my post to comment that I'd LIKE to use it as an Ethernet cable and it is not currently used for anything. I just want to see if it will cause some problems if I do this (won't work) as the jacket doesn't specifically state Cat5 or Cat6 etc. – stackexchangediy May 27 at 19:23
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    If it doesn't actually have a CAT rating, then it may not actually be rated for Ethernet. The only markings I can see relate to the insulation. – Simon B May 27 at 19:30
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    You'd have to see if there are individual twisted pairs (with or without shields), or whether it's a bundle of untwisted wires. If twisted pairs, you might be able to run ethernet over a short distance. If it is not stamped Cat5 or Cat4, I don't think there's much you can do over anything more than a few feet. (Your mileage may vary) – P2000 May 27 at 19:32
  • Ok, thanks. At the very tip there are 8 untwisted conductors but I could strip it and look a little farther. The alarm guy texted "sure can use for Internet" but I'm a little skeptical (I've never interacted with him or used him but he appears to have serviced for prior owners) – stackexchangediy May 27 at 19:55

So I think it actually IS an Ethernet cable.

Looking farther into the hole on the cable markings, I see "ETL VERIFIED TO TIA/EIA 568B."

However, I think I don't know where the cable comes out on the other side. The ones in the "structural panel" that are yellow are all rated CM and this one is CMR, so I don't think it is the same cable.

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    TIA/EIA 568B is a family of specifications, under which Cat 3,5 and 6 cables fall. I doubt it's any of those without the marking. It does have twisted pairs, it has standard paired colour coding, could be balanced, likely not shielded, might carry old ethernet, and my guess it's for your alarm's phone hookup to a monitoring service. – P2000 May 28 at 1:35
  • Ok, thanks! I bought a tone and probe kit to trace out some of the other wiring (worked great) and wherever this cable is going, it definitely doesn't go to the "structural panel" that the alarm guy said. Oh well... – stackexchangediy May 29 at 0:10
  • So, for posterity's sake, I toned out the cable in the attic, and it is definitely not going to the structural wiring box but rather down a conduit near the back of the house which I assume is running to the phone demarc box. – stackexchangediy May 31 at 1:57
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    Also, the cable portion that comes out in attic says "Cat 5e" so it is definitely an Ethernet cable. – stackexchangediy May 31 at 1:58

It's a fire rated ethernet cable and the other end is probably near the duct manifold where a fire sensor should be.

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