Sy cable question

[nathansinar]

Hi guys new to the forum and will introduce myself shortly

I have attached an image of a spur i have taken as you can see from the attached image

I am doing a trainee maintenance engineer role and just wanted some info on the below.

1.) when using sy cable do you have to earth the sheeth? i have had various reponses saying it is good practice but you can get away with using the cpc inside the cable and that alone?

2.) in the image i have posted becuase the sheeth hasnt been used an earth from the the spur to what ever it is feeding, does an earth need adding from the back of the spur plate to actual spur box as it could become live?? is it a reg that this needs to be done?

Thanks for help!

Nathan

 

[LeeH]

The amount of times I've seen it with no sheath left on it due to UV deterioration....leaving just the rusty braid there.

So let's leave it floating. Genious!

 

[Flanders]

From what i have come across on various sites it that it seams to be common pratice to use sy cable to supply equipment from bus bar tap off boxes , and use to make up extention leads in industrial environments , when i ask the question why tbey use this cable there answer is that its more robust than flex and Swa is far too heavey duty and its difficult if not impossible to terminate an swa into a camando plug (although i have seen some poor attempts ) ,i have been ask what i would suggest , to which i don't have an answer , so it there a more suitable cable to use? It would be interesting to send a fault current down some SY and see what happens , maybe JB from the Ytube will give it a go .
Looking at the ops install it neads
1 . the back box securing to the wall
2. the cables sleaved with the correct identification
3. if Sy cable is the only choice then gland it off with an sy gland

 

[Wilko]

Edit

 

[LeeH]

That's the stuff!

 

[DPG]

I've always thought it a very nice looking cable. If that counts for anything Daz

 

[LeeH]

@Flanders you can get a really tough flex but the name/code escapes me.

 

[Wilko]

Sorry about the almost random pic. I was part way through some rubbish and tried to delete it all, but the pic she stuck.

 

[darksideby182]

Refrigeration Engineer favourite this cable. As others have said its a poor cable.

 

[DPG]

See loads of aircon units wired up with it as well. Up to the external isolator in SWA and then out to the outdoor unit in SY. Daz

 

[darksideby182]

Yep seem to think it ideal and always it the wrong size of core normally 2.5mm when it should be 4mm/6mm

 

[Darkwood]

SY outer sheath is not UV tolerant either and will breakdown quickly if exposed so totally the wrong choice exposed outdoors.

 

[DPG]

Indeed darkwood. But them aircon guys love it! Daz

 

[sysrq]

All I can say is that majority of electricians always forgot to connect the braid of SY cable to earth, so I always have to reconnect everything properly with ferules, especially on cee form commando plugs where the screws always crush the cable strands resulting in fires, damaged machinery due to phase loss and everything, I can't see end to this.
Wish someone would come up with plugs where ring terminals are being utilized only (reduced possibility of broken threads, screws and pin walls). Seems like I'm the only one who complains about this.
Another thing is that all of them are very different from each other, thanks to competition between manufacturers.