Overhead supply cable.

[Steambod]

Well only one person suggests that, PVC t&e is not UV stable!

Nothing will detect a disconnected earth, only proper testing.

True, T&E in the long term will degrade due to UV. However this is over many years. On the mobile classroom installations mentioned we rarely had any problems (out of several hundred units) and mostly it was due to the taping used to hold the cable to the wire, neither did we have trouble with catenary movement causing the cable to fail (could be a problem on really long spans but most were around 5-8m. All installations were checked every three years so any degradation of the cable would be picked up in plenty of time.

 

[holmslaw]

..

 

[bernardgreen]

Interesting point about flexing at the walls. Can a catenary be split at the walls (a 'Y' shape) to reduce or distribute this movement?

It can reduce the strain on the fixings by sharing it between two but it needs to be designed properly.

Last catenary failure I saw ( Network Rail excluded ) was two house bricks pulled out of a wall. Wind induced vibration over the few months it had been installed had ( according to the insurance assessor ) weakened the mortar to brick bond to the point where the bricks to which the bracket was attached could just slide out.

 

[Lectrician]

I have seen a facia pulled off They had not even tried to fix it to the end of a rafter.

Amazing how many times you see a catenary up, with the cable hanging off it due to the use of non UV stable cable ties.....