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Hi Group

Had a third party inspection by a NAPIT tester, to get building control approval for a pv installation.
He has failed the cable run in Twin and Earth under my floorboards even though its greater than 50mm from surface. No 30ma RCD fitted to this circuit.

I though it was acceptable if the cable was 50mm or greater from the top of the joists?
Thanks for advice in advance

Iain
 
Did he give you a reg No that you are falling foul of?

Unless it's relevant to PV which I have no experience of, there's nothing wrong with running cables below floorboards.
Your biggest concern would be building regs.
 
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Is it 50mm from the ceiling below too? ;) Edit - as Dave points out its not applicable anyway to running through floors.

Likewise I have no PV experience so leave that to the PV guys.
 
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The inverter manufacturer SMA Sunny boy guidance says do not use an RCD with a tripping current of less than 100ma to prevent false tripping which the NAPIT tester will not accept (he wants a 30ma RCD.

The cable is fully visble for all of its run from airing cupboard and along landing.

I have not asked him yet to quote the reg he's failing it on.
 
The inverter manufacturer SMA Sunny boy guidance says do not use an RCD with a tripping current of less than 100ma to prevent false tripping which the NAPIT tester will not accept (he wants a 30ma RCD.

Is the cable installed in a wall then?
 
Clipped direct to wall, not in wall and then under flooirboards

Then I would say that you do not need an rcd, it sounds like the inverter manufacturer are saying that if you use an rcd then it should be 100ma. It doesn't sound to me that they are saying that they require one.
 
Since when? There is no requirement for cables to be RCD protected purely due to be installed under a floor, regardless of whether they are 50mm deep or not!

If you think otherwise please do quote a regulation number to back this up.

Dave, could you please read my post again that you've taken my quote from.

You'll see that I'm agreeing with you that cables below the floor and above ceilings do not need rcd protection.

Post 11
 
Maybe he's pulled it because you are too close to the ends of the joist thus a structural issue?

If not ask for more details and regulations that you have supposedly broken.
 
Dave, could you please read my post again that you've taken my quote from.

You'll see that I'm agreeing with you that cables below the floor and above ceilings do not need rcd protection.

Post 11

I stated that the 50mm rule only applies to walls (ie. T&E cables buried less than 50mm require RCD protection unless otherwise protected)
You replied stating that it also applies under floors

What is there to misunderstand?
 
Dave, could you please read my post again that you've taken my quote from.

You'll see that I'm agreeing with you that cables below the floor and above ceilings do not need rcd protection.

Post 11

To be honest Andy I also read your post as meaning cables below need RCD protection, at least the second part looks like that and the first part looks like you don't think it needs RCD protection!
 
I stated that the 50mm rule only applies to walls (ie. T&E cables buried less than 50mm require RCD protection unless otherwise protected)
You replied stating that it also applies under floors

What is there to misunderstand?

The misunderstanding was because I took 'Since when has running a cable under floorboards/above a ceiling required RCD protection?' To mean just that and I agreed with you.

And 'The 50mm reg is applied to cables buried in wall' to mean that cables below floors do not need to be burried >50mm and I disagreed with that.
 
To be honest Andy I also read your post as meaning cables below need RCD protection, at least the second part looks like that and the first part looks like you don't think it needs RCD protection!

Fair enough HHD, but if you read my posts I've said that on the face of it this installation does not require an rcd.
 

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