# Interest group forums > Electrical Contracting Industry Forum >  Cable fault

## ians

I am called out out site to check why 1 camera is not working (installation done by others) i find a page long list of issues... 3 days later everything is working ...linked to idmss plus ...1024 kb/s on all 8 channels... including the replacement of 4 cameras.

I invoice the customer and i get paid.

3 days later i open the app and check that everything is still working fine... 100 percent.

a week later i notice 1 camera ...connection fail... i go to site ...first thing i notice is the camera 8 indicates 154 kb/s so i test the voltage at the camera 12.3 VDC ...all good... plug in my home made test probes so that i dont have to cut the cables... no continuity ... cut the cable half  way (30 m) one side has continuity and the other doesnt... i replace the 60 m of cable... what a mission double storey ...long ladders etc.... reconnect and we are back to 1024 kb/s ...all good.

here the thing...

I get back to the workshop and check the cable for physical damage ... none ... not even a nick on the cable ...i do a continuity test the centre pin 0.6 ohms ...all good ... i do the same test on the braid... 3.567 megohm ...so i start cut the cable... after 8 metres i find the copper braid id fill of grey powder... i cut 2 metres off the cable and retest ...all good.

I strip the outer sheath and expose the copper braid ...it is covered in this powder

I notice the braid is made up of aluminum and copper ...not just copper ...the centre core was thinner than the other cables i checked... it didnt surprise me ...the shyte grade cabling out there at the moment is shocking.

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## adrianh

Wow - that is really interesting. Imaging if such a bit of wire get used in an airplane....MCAS failure will be the least of their worries.

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## ians

> Wow - that is really interesting. Imaging if such a bit of wire get used in an airplane....MCAS failure will be the least of their worries.


The real interesting part... it is sold as "military grade" 

Now when i go look for cable... i take a sharp blade... a vernier ...a cable cutter ... a gas torch. 

The cat5e ...I first cut the cable and check the ends to make sure the cable is no copper coated aluminum... then check the core thickness (it ranges from 0.35 to 0.47 mm... some even vary within 200 mm) ...then burn the core to make sure it glows red and doesnt just melt ...lastly check the pair twist ...to make sure it is a nice tight twist.

The coax ...Cut the cable and check the cores and braid ...the crap stuff ...you can see as much as 60 % is aluminum... first I strip and pull on the braid ...the crap stuff the braid just breaks as you pull on it... i then strip the centre core and see if it breaks off as you try remove the insulation... the crap stuff is supper difficult to remove ... the good quality stuff ...2 turns and the insulation slides off easy ... same thing burn the wire ... if it glows red and diesnt drop ...its the better stuff... then the real challenge starts ...trying to find a BNC connector to fit.

I contacted Hellerman to complain that there crimper was junk because it couldnt crimp the centre brass pin... the first reply was ...nobody crimps the centre pin... anyway it turns out that either the BNC connector or the centre core of the cable is not compatible.

Anyone have any suggestion where i can find a cable and BNC connector which are compatible with each other ...which i can crimp the centre pin... someone needs to get smart and make a soldering iron which can hold the centre pin... full of melted solder ..then release it as soon as it is fitted. 

I have come to realize that its not the quality of the products ...its all rubbish ...its us old people who still think that stuff is made to a standard so that when you buy a product it fits other products because of the standard set to prevent this shyte from happening.

An example ...i buy a pile of PioLED flood lights ...fit them and get paid... all good... not really months later ...the company runs late with stock take and people leave when it is already dark... to find that the flood lights are not working... i get a call to check the lights... first thing i think is the circuit breaker must have tripped ...not ...then it must be the day/night switch... not all the flood lights have popped... mounted 8 metres in the air... i go take them all down and return them to the wholesaler ... to find out that there was a faulty batch... so i indicated that i would be sending my bill for the 3 hours ...i was told they dont entertain claims for faulty products... i had to pay for all the new lights and they will decide if they are going to refund me once they have checked the lights... NOT IMPRESSED WITH PIOLED LIGHT FITTINGS... this is not the first time.

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## ians

After doing some research with regards to using cat5E cables for cctv.


Max current per wire = 0.577 amps 

Using the wire as a for POE with 24 VDC ...should be no problem... for small standard cameras... i would pay attention if using Cat5 CCA.

However using the cable to run 12VDC cameras might not be that simple... if the cable is as per spec... the wire thickness should be around 0.51 mm  bare copper (0.205mm square) i did some tests on numerous BC solid cat 5E cables... some where as low as 0.38 mm ...still not a big deal... until you start installing modern cameras with IR lighting... PTZ etc.... still not really a big deal... 

Now throw in a cheap cat5E CCA cable ...100 m long run ...cable thickness... wire resistance... volt drop... underground piping which is not water tight... exposed connection ...connection in trunking which is not insulated from the elements... and you wonder why you get ghosting ...shyte picture quality.

A customer rejected an installation due to bad picture quality ...nobody could find the cause... the installer is not paid and instructed to remove the entire installation... i would bet money that the problem was caused due to poor quality and incorrect cable selection. 

Why did i even step over this line... the electrical industry is bad enough... with skilled artisans... just imagine an industry with suitably qualified people with 2 days training  :Frown: 

Try find a 0.25mm bootlace ferulle ...it helps prevent the little wire breaking when you push the cables in the water tight enclosure. 

Doubling up on the data wires is a bad idea ...rather triple up on the power to reduce volt drop especially if you are using a CCA cable (55 % higher DC resistance... so they say)

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