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Hi all,

I have been installing CCTV camera for a few months. But right now, I have been placed on the service team... I am supposed to replace a 300 meters long cable for a faulty CCTV camera. Another member of the team has identified the fault to be the cable (one of the wire is cut somewhere apparently).
Instead of finding where it is damaged, they suggested replacing the cable entirely.
I am wondering if there's any way to locate the cut? I do not have any fancy tools (TDR for example). What other options do I have apart from physically looking at the cable? (I am thinking it might be broken inside the insulation from when it was pulled).
The fault report from my colleague says:
  • power to camera ok
  • cannot ping camera
  • replaced camera, still not working
  • toned and tested cable
  • line 4 defective on cable
  • tested joints on cable
(I have no idea what that last line means).
 
Hi all,

I have been installing CCTV camera for a few months. But right now, I have been placed on the service team... I am supposed to replace a 300 meters long cable for a faulty CCTV camera. Another member of the team has identified the fault to be the cable (one of the wire is cut somewhere apparently).
Instead of finding where it is damaged, they suggested replacing the cable entirely.
I am wondering if there's any way to locate the cut? I do not have any fancy tools (TDR for example). What other options do I have apart from physically looking at the cable? (I am thinking it might be broken inside the insulation from when it was pulled).
The fault report from my colleague says:
  • power to camera ok
  • cannot ping camera
  • replaced camera, still not working
  • toned and tested cable
  • line 4 defective on cable
  • tested joints on cable
(I have no idea what that last line means).
A few questions from what you have posted
Is this an install that has previously worked ok and has failed or is it a new install

Is this an IP camera system

What type of tone tester was used, I would suggest using a tone tester that can detect open circuit faults

What is the cable type you are using is it a multicore or multipair

How many joints does this 300m cable run have and are these joints a result of similar faults in the past, I'm not understanding why the fault has not been isolated to one section of cable between 2 of the joints by the previous team member
 
"Tested joints on cable" might mean testing the terminations?
ie there aren't any joints IN the cable.
 
Given that it would be made up of three 100m drums lengths I would suggest you start by identifying the joins and then testing between the ends of each of the three lengths so you can start to narrow it down.

However, I would question why it is 300m long.
100m is the maximum length for a data cable unless you have some active equipment in between.

If the 300m is just made out of joined lengths then you can't really expect it to work.
If it does have switches in between then perhaps one of those has failed.

Are you sure it is 300m and not 300 ft?
 
300m is very long for Ethernet / PoE as usually the limit is 100m.

You often get cable is 1000' = 305m runs so it could be done in one section without joints.
 
If they have done it in one drum of 305 there shouldn't have been any junctions - unless they have made it up of odds.
One way to check would be to look for meter markers along the cable which might give a clue as to if it is a continuous length.
Either way the distance is out of spec.
 
Given that it would be made up of three 100m drums lengths I would suggest you start by identifying the joins and then testing between the ends of each of the three lengths so you can start to narrow it down.

However, I would question why it is 300m long.
100m is the maximum length for a data cable unless you have some active equipment in between.

If the 300m is just made out of joined lengths then you can't really expect it to work.
If it does have switches in between then perhaps one of those has failed.

Are you sure it is 300m and not 300 ft?
Cable length is not limited to a "standard" 100m length it is possible to get 500m drums of cat 5 & 6
In the past I have purchased various cables on special order in 1Km lengths and very occasionally even longer, with cables that long if installing them in one continous length it requires some planning to avoid damage during the multiple pulls that are needed as it can take a number of days to complete the install
 
Cable length is not limited to a "standard" 100m length it is possible to get 500m drums of cat 5 & 6
In the past I have purchased various cables on special order in 1Km lengths and very occasionally even longer, with cables that long if installing them in one continous length it requires some planning to avoid damage during the multiple pulls that are needed as it can take a number of days to complete the install

I'm sure you can special order pretty much anything, but I'd suggest 100m drum or 305m box is probably a lot more common for the average CCTV install!

The only reason I'm thinking 100m drums is the OP mentions joints on cable - and other than previous damage or perhaps for ease of installation, then this is the obvious thing that springs to mind.

I'd imagine you would have to have quite a specific use case for a 1km run of Cat 5e.
I'd certainly not look forward to trying pull that.

The 100m maximum length requirement is for TIA/EIA-568-B - well 90m technically excluding patch IIRC.
Although it may still work, anything longer than that is deviating from spec, especially when using PoE as there would be quite a bit of volt drop. I think there are some systems now that can operate a long range PoE for CCTV to push that to 250m, but not something I've had any experience of. Personally, for anything over 100m I'd just use fiber and power the equipment locally - you can even buy it preterminated these days if you don't have the kit.
 
I'm sure you can special order pretty much anything, but I'd suggest 100m drum or 305m box is probably a lot more common for the average CCTV install!
I didn't specifically state cat5
In the past I have purchased various cables on special order in 1Km lengths
Cat5 and coax on 500m drums is quite common as are other cables, who would want to be using a soggy cardboard box of cat5 when you outside in the rain
The only reason I'm thinking 100m drums is the OP mentions joints on cable - and other than previous damage or perhaps for ease of installation, then this is the obvious thing that springs to mind.

I'd imagine you would have to have quite a specific use case for a 1km run of Cat 5e.
I'd certainly not look forward to trying pull that.
Cables that flex easily are not a problem with a bit of planning of how you stage the pulls, I have pulled a 7H1.5 pyro through ducts across a factory in one continuous 750m run and I have done similar runs in coax of various types

With regards to 1Km of Cat5 you are not seeing the bigger picture of making a job cost effective and reducing or minimising wasteage you will get 10 runs of 100m from a 1Km drum and waste nothing or 11 runs of 90m and only have 10m over
The 100m maximum length requirement is for TIA/EIA-568-B - well 90m technically excluding patch IIRC.
Although it may still work, anything longer than that is deviating from spec, especially when using PoE as there would be quite a bit of volt drop. I think there are some systems now that can operate a long range PoE for CCTV to push that to 250m, but not something I've had any experience of. Personally, for anything over 100m I'd just use fiber and power the equipment locally - you can even buy it preterminated these days if you don't have the kit.
I have installed runs upto 140m that worked ok when installing point to point radio links and when testing the end to end capability across the link it had no packet losses

I agree on the fibre although the pre terminated lengths are a pain to install while not damaging the connectors in the process, I prefer to terminate after installation
 

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