Xlpe swa

[SparkusMaximus]

Hello peeps,

Has anybody got any concrete current carrying capacity figures for XLPE SWA, there is a thread about how it has a greater CCC than normal SWA.

However I though most SWA was XLPE as its just cross linked polyuratane, the compound of the outer sheathing I guess.

I don't know if there is some confussion here and as its not in the BRB unless I have gone completely potty, it feels akin to bunging in a cable smaller than required as a bloke down the pub told me XLPE has a greater CCC or at least thats what ill be saying in court if it al goes wrong as where do I prove this point.

Now please don't get me wrong I am not suggesting anybody who is stating this is wrong its more than likely I have missed something somewhere, hence I am trying to understand where we stand with this stuff, and if a mistake has been made stop others from following.

Cheers guys.

 

[Chr!s]

All depends upon what conductor temp your working with.

 

[SparkusMaximus]

I see that and it seems that we are getting the figures from the 90 degrees, maybe thats where I am getting confused, I thought we used 70 degrees, when is it ok to use the 90 degree calc?

 

[Chr!s]

You can use the 90 C if the equipment connected can operate safely at the 90 C, if the rating is that of 70 C, then the conductor temp at the terminal will need to be 70 C

 

[telectrix]

agree with chris here. e.g 10mm xlpe is rated 81A @ 90deg. if the terminations are rated only to 70, then would have to derate accordingly. i don't know the ccc at 70 deg. probably around 70A.

 

[Chr!s]

However I though most SWA was XLPE as its just cross linked polyuratane, the compound of the outer sheathing I guess.

I believe this is a requirement of BS5467, Prysmian only produce xple SWA

 

[SparkusMaximus]

I thought it was the XLPE bit that was giving it the higher capacity, but we have been talking about the conductor temp.

Next silly question, how do you know what is rated to 90 degrees, or as I am guessing most things are 70 degrees unless otherwise stated. Would you find anything domestically rated to 90 degrees.

Thanks for clearing that up, twas I who was confuzzled.

 

[Risteard]

Generally if the terminals are not rated for running at 90 degrees then the thermoplastic (70 degrees) rather than thermosetting tables are used despite the fact that cross-linked polyethylene (XLPE) rather than PVC cable is being used.