Have I possibly damaged the underfloor heating mat?

[ppelec100]

So I’m fitting an electric underfloor heating mat by pro warm. I was testing it for continuity between L N and got 88ohms which is what it should be according to the instructions.

It says to do IR test at 500V but it doesn’t say between which colours. So I did L N and got 0.00ohms. Have I damaged the mat? I realised after maybe I shouldn’t have done that. I did L E and N E and it was >1049Mohms.

I looked at the instructions and it doesn’t say which cables to IR test between which was annoying.

 

[Tony M]

WOW, can easily happen to any one of us
can we see if there is a fuse inside the mats cabling or its controller? ,

 

[Teddy Lop]

Your readings sound perfect, you want a mega high reading to earth, generally tie l+n together and test L+n to e but for an element it won't matter

L to n on insulation test will test zero as it's such a high scale v. low resistance.

 

[oscar21]

You wont damage the mat by sending 500 or even 1000V from the megger down the live and neutral wires, the current from these meters is so low it wont do anything, I think its 1mA max.

On a similar note I've fitted loads of these mats over the years and tested each on before and after and never encountered any issue/fault anywhere. So I lay my own mat in my bathroom the other year and don't bother with the testing as its always been ok in the past, lay my own tiles very carefully and when I come to power up the mat for the first time - zilch. Must have been faulty from the factory, unbelievable.

Luckily I'm currently re modelling that bathroom and have just taken the floor up, this time I'll be a lot more through.

 

[davesparks]

It says to do IR test at 500V but it doesn’t say between which colours.

I looked at the instructions and it doesn’t say which cables to IR test between which was annoying.

The instructions tell you to test the insulation and you already know from the result of the previous test that the L and N are not insulated from each other, they are connected together, so what further instruction is needed?