Question Testing for CAT 6 cable break

[Foozle1]

Hi,

I have several long (100 feet plus) CAT 6 cables that have breaks in one of the strands. I know which strand from testing continuity. Is there a way to test to see where the break is in the cable? I tried running 6 volts through the strand and used a pen tester to see where the tester stops beeping, but it appears the 6 volts is somehow transferring enough of a signal to the other strands that the pen tester beeps the entire length of the cable. The cable is not being used currently, so I can visually inspect the entire length and I don't see any visible signs of damage.

Thanks!

 

[faalin]

Not sure what tester you have, I use a Fluke Microscanner2 and will tell me how far down the cable the break is, or if good how long the full cable is.

You might try and just re crimp the end, i've had a few cables where re punching the pins in the ends fix the cable.

 

[bill001g]

It is kinda rare for a cable to be damaged in the middle almost all damage is on one of the ends. Even more that there is no visible damage. What you would be looking for when the cable is not actually cut in some way is some indication that cable was crimped or bent. It takes a lot to damage wires.

I know expensive fluke meters can tell you fairly accurately the distance to a break. Not sure how they do that. The ones that test fibers look for reflections of the light to detect cracks and estimate the distance. Maybe copper works similar.

I suspect buying new wire is going to be cheaper than looking for a even a clone meter that can find the break. You would have to also spend say 5 to 10 dollars to get a cable splice that would not degrade the signals. Unless the wire is installed where the install costs are very high it always tends to be cheaper just to replace a defective ethernet cable.

 

[Foozle1]

Not sure what tester you have, I use a Fluke Microscanner2 and will tell me how far down the cable the break is, or if good how long the full cable is.

You might try and just re crimp the end, i've had a few cables where re punching the pins in the ends fix the cable.

Faalin, thanks for the quick response. I just have a Fluke 117, which doesn't scan for breaks. I also have the pen tester, which doesn't work as it is detecting a signal from the adjacent lines, I guess. I already cut off both ends to eliminate a crimping issue. I'm testing continuity with the Fluke 117 by attaching directly to the white/orange strand - and it fails continuity, where as the other 7 strands all have good continuity. This is just a hobby for me, so probably not worth investing in a Microscanner.

 

[Foozle1]

It is kinda rare for a cable to be damaged in the middle almost all damage is on one of the ends. Even more that there is no visible damage. What you would be looking for when the cable is not actually cut in some way is some indication that cable was crimped or bent. It takes a lot to damage wires.

I know expensive fluke meters can tell you fairly accurately the distance to a break. Not sure how they do that. The ones that test fibers look for reflections of the light to detect cracks and estimate the distance. Maybe copper works similar.

I suspect buying new wire is going to be cheaper than looking for a even a clone meter that can find the break. You would have to also spend say 5 to 10 dollars to get a cable splice that would not degrade the signals. Unless the wire is installed where the install costs are very high it always tends to be cheaper just to replace a defective ethernet cable.

Bill,

Thanks for the quick response. As I mentioned in a response to faalin, I've eliminated the possibility that the ends are the issue by cutting them off and just testing the wires directly. The cable isn't installed - I was running it outside to some outdoor security cameras using Epoe - so about a 1000 foot run. This is indoor cable, so could be the heat and cold over time caused the break, plus any other various outdoor hazards, like wind, animals, etc. Ultimately I need to just do direct burial cable at some point, but I have to go through woods, so the roots, might be a nightmare.

I'm just trying to salvage as much cable as possible for various other uses, so was trying to find a creative way to find the break rather than just cutting randomly and testing. I was wondering if the tech they use for finding breaks in underground wire would work (they sell cheap versions on Amazoin), but I may run into same issue of the adjacent strands giving a false signal.

Thanks!

 

[bill001g]

The only reason you bury the cable is to avoid it getting damaged by say lawn equipment. I suspect in a wooded area you could secure it to the surface with those wire landscaping staples in difficult areas. If you can get even 1 inch buried it is likely good enough as long as you remember to not dig with a shovel there.

I saw the Epoe stuff but never looked into how they managed to get power to go that far. You can use DSL signaling to carry data at lower rates but power is purely a resistance thing and there is a lot of loss per foot on the thin wires used on ethernet.

Maybe gamble and just cut the wire in half. You likely then get 50% of your wire for sure. You could I suppose cut 10ft off one end and continue until the problem disappears. Have to get lucky and pick the proper end to start with.

 

[Gururu]

You might be able to find it by connecting the two ends of the broken wire to the tester and wiggle the wire along its length to see if a signal is generated. The broken ends might be so close that a wiggle can fix the connection for a moment.

 

[Foozle1]

You might be able to find it by connecting the two ends of the broken wire to the tester and wiggle the wire along its length to see if a signal is generated. The broken ends might be so close that a wiggle can fix the connection for a moment.

Great idea, I'll give that a try!

 

[Foozle1]

The only reason you bury the cable is to avoid it getting damaged by say lawn equipment. I suspect in a wooded area you could secure it to the surface with those wire landscaping staples in difficult areas. If you can get even 1 inch buried it is likely good enough as long as you remember to not dig with a shovel there.

I saw the Epoe stuff but never looked into how they managed to get power to go that far. You can use DSL signaling to carry data at lower rates but power is purely a resistance thing and there is a lot of loss per foot on the thin wires used on ethernet.

Maybe gamble and just cut the wire in half. You likely then get 50% of your wire for sure. You could I suppose cut 10ft off one end and continue until the problem disappears. Have to get lucky and pick the proper end to start with.

Bill, the main reason to bury is that squirrel or chipmunk like to eat through the sheathing. I had one run that I stapled to trees to try to help with that issue, but they still managed to climb on the wire and somehow chew through a spot. After several rains, the cable filled with water and shorted out my camera!

I took apart that damaged camera and noticed that two sets of the strands were combined, so I wonder if that is how they are boosting the signal, by using four wires to transmit rather than two. Just a guess.

Yeah likely will have to gamble. I can at least make use of short 10 foot runs for other stuff over time. Maybe I can inspect and look for signs of kinking or something to give me a start.

Dave

 

[bill001g]

Maybe use the very cheap wire conduit that is split down the length. It is easy to install small pieces where it is exposed. You would still need to use waterproof cable. You could use solid water proof conduit but then you need to pull the wires though. If you ran it the whole way you could use indoor cable but last time I looked it was still a bit cheaper to just buy outdoor cable rather than the conduit/indoor cable

 

[kanewolf]

Bill, the main reason to bury is that squirrel or chipmunk like to eat through the sheathing. I had one run that I stapled to trees to try to help with that issue, but they still managed to climb on the wire and somehow chew through a spot. After several rains, the cable filled with water and shorted out my camera!

Yep. I have had rabbits eat through fiber cabling. Some kind of critter protection is required long term.

 

[ex_bubblehead]

What you want is a reflectometer. Be prepared to pay thousands for such a device.