Expelair VX100T timer query

[JohnW2]

It does not look like a vx100t

Exactly. I didn't bother to post an image, but that's what the (dozens or hundreds of) VX100T wiring diagrams out there look like.

I have top say that it looks to me as if (a) the photo (assuming it's the OPs fan) is not a VX100T and (b) it seems pretty likely that the G'Y core is (in the photo) being used as a live conductor.

Kind Regards, John

 

[Don4ld]

Thanks for your input everyone. It does seem that a timer fan will not run on the wires I have as has been said, but here is the wiring diagram from the manual.

 

[JohnW2]

It does seem that a timer fan will not run on the wires I have as has been said, but here is the wiring diagram from the manual.[/ATTACH]

I'm afraid that I am still confused. I thought you had told us that the previous timer fan did work as expected with "the wires you have" (which presumably have not changed)?

To be sure, can you clarify what the photo you posted is (since it doesn't look like a VX100T), and why that green/yellow wire is connected to the middle terminal?

Kind Regards, John

 

[EFLImpudence]

To be sure, can you clarify what the photo you posted is (since it doesn't look like a VX100T),

It does look like the diagram now shown.
I don't understand why that does not appear on any searches.

and why that green/yellow wire is connected to the middle terminal?

Because there are three wires and three holes.

 

[Don4ld]

 

[JohnW2]

It does look like the diagram now shown. I don't understand why that does not appear on any searches.

Quite - it's very odd that the umpteen wiring diagrams on-line are different from that.

Because there are three wires and three holes.

True, but that doesn't alter my question as to why the G/Y is connected to the middle terminal, given that that terminal is labelled 'N' in the diagram now posted, and that, in the OP, it was said that there was "a single live, a neutral and an earth" in the cable.

Kind Regards, John

 

[Don4ld]

Because there are three wires and three holes.

Ok...my sarcasm senses are tingling... so the earth wire shouldn't be connected at all? Do you have any suggestions for what kind of fan will run on the existing wiring and not run continuously?

 

[EFLImpudence]

Donald,

If your previous fan had a timer for running on after the light was switched off and it worked then the new one will do the same.

That at least one of the wires has been used for something it should not have been, means we cannot tell which wire does what.

You will need to determine which wire is always live (I would think brown but who knows what previous person did?)
which one becomes live when the light is on (might be green/yellow, might be blue)
which one is neutral (might be blue, might be green/yellow connected to neutral or still connected to earth)

If it is the latter, then it should not be used until rectified and wired properly.

 

[opps]

Ok...my sarcasm senses are tingling... so the earth wire shouldn't be connected at all? Do you have any suggestions for what kind of fan will run on the existing wiring and not run continuously?

From the photo that you posted- you can see a square with a smaller square inside it. That means that the product is double insulated and thus doesn't need an earth.

https://www.pat-testing-course.com/blog/faqs/electrical-appliance-classes/

As John suggests, it seems likely that someone previously decided to use the yellow/green"earth" cable as a neutral. The two other cables are functioning as the permanent live and switched live.

If your fan is running constantly then it may be the case that you have the perm live and switched live the wrong way around.

For the record, I am not advocating that you continue to use misleading wiring, but I can see no logical reason why it shouldn't work.

 

[EFLImpudence]

As John suggests, it seems likely that someone previously decided to use the yellow/green"earth" cable as a neutral. The two other cables are functioning as the permanent live and switched live.

You cannot say that.
If the green and yellow is connected to earth it is dangerous.

If your fan is running constantly then it may be the case that you have the perm live and switched live the wrong way around.

That does not cause a fan to run constantly. It will go off with the light.

For the record, I am not advocating that you continue to use misleading wiring, but I can see no logical reason why it shouldn't work.

...with the wires in the correct terminals but we can't tell that.

 

[JohnW2]

As John suggests, it seems likely that someone previously decided to use the yellow/green"earth" cable as a neutral. The two other cables are functioning as the permanent live and switched live.

As EFLI has said, a worse possibility is that it might still be connected to earth. In the absence of RCD protection, that would still work, but would not be 'safe'.

If your fan is running constantly then it may be the case that you have the perm live and switched live the wrong way around.

As EFLI has also said, that would not cause the fan to run continuously (even if light was off). If one of the avail;able conductors is a permanent live, and if that is the one he connected to both L and T, then that (and only that) arrangement would result in the fan running continuously.

Kind Regards, John

 

[JohnW2]

You cannot say that. If the green and yellow is connected to earth it is dangerous.

Indeed, potrentially dangerous. However, as I have just noted, the fact that the fan now 'works' (with some wiring arrangements) means that that (G/Y is connected to earth) could only be the case if there is no (or no working!) RCD protection - since a 15.7W fan (68mA, even if PF=1) should be more than enough to trip an RCD.

Kind Regards, John

 

[ban-all-sheds]

From the photo that you posted- you can see a square with a smaller square inside it. That means that the product is double insulated and thus doesn't need an earth.

The fact that it does not need one does NOT remove the requirement in the Wiring Regulations for one to be taken to that point.

For the record, I am not advocating that you continue to use misleading wiring

Hopefully not - the problem is not the use of a G/Y conductor as a live one - for a sheathed cable that is allowed, as long as it is oversleeved at each end to indicate what it really is, the problem is that there is no earth going to the fan, and that is simply not allowed, double insulated fan or not.

So, to be precise with the use of English - the existing wiring can be used for a timer fan, but it may not be.

 

[opps]

You cannot say that.
If the green and yellow is connected to earth it is dangerous.


That does not cause a fan to run constantly. It will go off with the light.


...with the wires in the correct terminals but we can't tell that.

"If the green and yellow is connected to earth it is dangerous."

I agree.

"That does not cause a fan to run constantly. It will go off with the light."

If you put the perm live into the switched live terminal, then the on/off state of the light switch is no longer relevant but yes, I accept that I was wrong, on most counts, tnx.

 

[opps]

The fact that it does not need one does NOT remove the requirement in the Wiring Regulations for one to be taken to that point.



Hopefully not - the problem is not the use of a G/Y conductor as a live one - for a sheathed cable that is allowed, as long as it is oversleeved at each end to indicate what it really is, the problem is that there is no earth going to the fan, and that is simply not allowed, double insulated fan or not.

So, to be precise with the use of English - the existing wiring can be used for a timer fan, but it may not be.

Agreed, my bad.