SOLVED Old extractor fan has TNL; new only has NL

[JohnW2]

I am still confused. The old fan worked but without the timer over-run. The OP replaced a fan that runs, with a fan that runs...

Indeed - that's what eBee and myself have both already said.

And I can not work out how a fan with a switched live from the light can work independently via the isolating switch. For that to be the case, it would possibly imply that the isolating switch has been wired such that it turns the switched live into a perm live.

Again, I've already made that observation - if the new fan is supplied with just N and a 'switched L' from the light, then if the isolator is closed, the fan will come on/off with the light, and the isolator could (by being opened) turn the fan off when the light was on, but the isolator could NOT turn the fan on if the the light was not on.

Kind Regards, John

 

[ebee]

Yes I think that we are all confused about what was not working and that is now working but could/could not have worked before.
If I understand it correctly, there was no need to change the fan. What am I missing?

 

[JohnW2]

Yes I think that we are all confused about what was not working and that is now working but could/could not have worked before.
If I understand it correctly, there was no need to change the fan. What am I missing?

If you're missing anything, it's probably the same thing as I'm missing, whatever that might be.

As you imply, I think the issue which offers the most scope for misunderstanding is the exact 'state' of the old fan immediately before it as replaced. If, as we both took the OP to be saying, it was working (but not as a timer fan) at that time,then it would seem that he has achieved nothing - and that (although he obviously did not know this), he quite probably could have achieved ';timer fan functionality' with the old fan simply by swapping the L and T connections.

 

[ebee]

Yes I think you are right John