Re: CAT5e cable

The simplest way I know of is to get samples and cut them open for detail inspection.

Without destructive inspection, there are a few tests. First, mass per length - heavier is better. Second is DC resistance of each conductor per length - smaller is better. For shielded twisted pair, the shield quality can be measured, but this requires special tools.

Joe Gwinn

I used CAT5 for sending fast logic signals and clocks between boxes in a big lithography system... not Ethernet. So I tested a bunch of different ones for attenuation and crosstalk and delay. There were radical differences. Individually shielded pairs worked best, S/FTP as I recall.

We picked one and included transmit-end equalization that could be switched in on the long runs.

True. You can specify such things, but dream on - the vendors won't notice of care.

The only things you can specify are the overall system-driven requirements like max attenuation versus frequency and distance, shielding effectiveness, and the like.

And buying sight unseen is almost guaranteed to end in tears.

Yep.

Life's like that.

Joe

What type of outer jacket did you buy? CL, CM, CMG, CMR, CMP, CMX, CMX2, CMX3, etc?

Are you dealing with any kind of fire or smoke related requirements? Some jackets trade slow burning, so that a fire doesn't spread as quickly, for generating toxic smoke. If you're installing cable in a vertical shaft that is full of potentially combustible insulation, you want something that smolders and not burn. However, if the cable is being run through an air shaft (plenum), you want something that doesn't generate much toxic smoke.

"Understanding Cable Jacket Ratings: CL, CM, CMR and CMP"

Incidentally, for an interesting outdoor experiment, cut about 1 meter of each type of cable, hold the wire vertically, and use a butane or propane gas lighter to ignite the lower end of the cable. Note which types of cables smolder or burst into flames, and the amount of smoke each type produces. Also, wear heavy gloves, use eye protection, and have a bucket of water nearby.

Yep. I've also seen this. The cable was very brittle and could be bent only a few times before it cracked. However, it has been too long and I can't recall what type of cable was being used. It was in a hospital so it probably was CMR flame retardant insulation.

Since you're complaining about the lack of "durability" and running cable through EMT conduit, you might want to calculate the minimum bend radius:

Outdoor cable usually mean UV resistant. It can also be direct burial cable where the space between the wires and outer jacket are filled with silicon slime. It does a good job of keeping the water out of the cable, but does make a mess. If used as a cable "drop" between the pole and a building, it should have a messenger wire to keep the Ethernet cable from stretching. Lots of interpretations for "outdoor cable".

Ummm... yes, it would be nice if you would disclose the maker and the numbers on printed on the cable.

"Ethernet Cable Identification for Beginners: Reading Print Legends"

Incidentally, watch out for CCA Ethernet cable. CCA means copper clad aluminum. CCA is cheaper than 100% copper, but everything else about it is horrible: "Why You Should Stay Away from CCA Cables?"

Last I heard, the EU forbid our plenum cable as when the fireproof Teflon plenum cable is charred, the gas is quite toxic.

Worse, I saw some cable from One well-known discount vendor. The insulation on the conductors was so thin and poorly applied that there were ~~cm long bare sections within the jacket. The problem was, two were bare in an adjacent location. What was the last time you looked for a short IN the middle of newly installed cable vs. at the end connectors????

Beware using filled cable indoors. That gel may well be flammable. There's something in the Code re: that.

I live where there is lightning; to me "between buildings" means fiber, period.

It's good for the doorbell and tying up the dog.

The gel is NOT flammable:

"Ethernet Cable Gel Filling Flame Test!"

The grease needs to be slimy to plug any air gaps which might cause water to crawl up the air gaps using capillary action.

After posting that, I went searching for what the gel formulation. I never did find anything authoritative, but did the mention in the 2nd video below that it's a wax and mineral oil mix. When heated, mineral oil vapors will burn (135°C / 275°F flash point) and is considered mildly flammable).

I blundered across these two videos demonstrating how to properly terminate CAT6 direct burial shielded cable:

"How To: Terminate Shielded Direct Burial Ethernet Cable"

"Cat6 Gel Filled Direct Burial Ethernet: Termination and Best Practices"

The termination tool shown in the videos seem to be useful. $60.

It's paraffin wax. No vegetables allowed - too tasty.

Joe