Online assistance for electrical trade people in New Zealand and Australia Login  |  Register  |   Forgot Password
Assistance for electrical trade people




Click here to send Forum Admin a pdf document for publication on this Topic

Documents must be less than 200k in pdf format

Posted By Topic: Novatherm insulation over cables

Jun 04 2015 15:06

Just had Smart Energy Solutions guy measure up for ceiling insulation. Happened to ask about derating of existing cables when installed under Novatherm blanket. He said he\'d never heard of this before. End of story.
Well I\'m not too worried (as my house loads are pretty small) but surely these guys should at least be aware of this? The way I see it, much of my TPS cabling will no longer have an \"in air\" rating.
What say you?

Jun 04 2015 18:46

this is another leaky building type issue, right house came in as i was doing a house, they said it was the sparkies problem, in this case ok but how the hell is a sparky supposed to know that insulation has gone in, they don\'t care, one day someone will blow the whistle and there\'ll be a lot of work for sparkies to retrocheck all the houses that have been done. like wise i rang earthwoool about their rating of their productr, she said it was up to the sparky to put in the right lights, wrong, the lights still need a cert that the insulation is correct rating.

Jun 04 2015 18:47

i\'d be tempted to pass this info via email onto the company together with the correct legislation, then they may have to do something about it.

Jun 04 2015 19:19

Fred, most of your TPS did not have an in air rating to begin with. It had a touching rating and would have after the installation of the insulation a partially surrounded by thermal insulation rating.

You are correct there has to be a connection between the certified rating of the insulation and the certification of the light fittings installed. This should be something that the designer, architect or engineer considers before specifying the materials. All to often it falls to the sparky to point out to the customer that the light fittings are not compatible.

Jun 04 2015 19:40

Don\'t we have to assume that BTI will be added anyway when we initially rate our cables?

Jun 04 2015 20:00

We do now but it wasn\'t always this way. Fred doesn\'t say if this is a new build or a retrofit.

Jun 04 2015 20:52

Apprentice, I\'m tired of having the buck passed, insulation installers have a code to work to, why the hell should we have to cover their poor performance?

Jun 04 2015 22:32

Sorry - should\'ve mentioned Retrofit to 40 yo house. Plenty of single cables run, Samajor.

Jun 04 2015 22:33

And thanks for all the answers/support. Will follow up with installer.