LED Lamps and extractor fan problems..

[ash_s3]

A friend of mine has just replaced some halogen GU10 lamps in his bathroom with LED lamps from Amazon.

Hes saying since swapping the lamps, the extractor fan runs continuously. (230v in-line unit in the loft with over run timer)

He tried swapping one LED lamp back to halogen and it worked as it should, timing out after 5mins or so.

Removed the halogen (with the lights switched off) and the fan fired up by itself!

Anyone come across this before? Sounds like a resistance issue to me, would a resistor sort this out?

Cheers

 

[uksparks]

I'm sticking with the theory of its wired incorrectly. I don't buy the inductance thing, we are talking about a bathroom light not a supermarket full of lights.

It's been poorly wired and incorrectly too and we have not been told the full picture like I've frigged around with it and don't know what I'm doing....

 

[ImpededLoop]

Not experienced this myself, but if it is wired correctly, you could install a relay next to the fan or the isolator to disconnect the SL from the lamps when the switch is off.

 

[davesparks]

How much voltage are we talking about here?

Also, when you say it turns the fan on, if it was only a capacitive thing, then surely it will run out this making the fan switch off on the end of its timer run?

How can capacitive coupling run out?

If the trigger for the fan is over sensitive then it could take next to nothing to trigger it.

 

[davesparks]

I'm sticking with the theory of its wired incorrectly. I don't buy the inductance thing, we are talking about a bathroom light not a supermarket full of lights.

It's been poorly wired and incorrectly too and we have not been told the full picture like I've frigged around with it and don't know what I'm doing....

You're mixing inductance and capacitance up, they are two different things.

Capacitive coupling is the effect which caused CFLs to flash and LEDs to glow/flash when installed on some 2 way switched circuits.

In what way are you suggesting it has been wired incorrectly? Can you describe the wiring method you think will cause this bizarre behaviour? I am curious as I cannot think of any way of connecting this which will cause he behaviour described.

 

[uksparks]

I can't think what it could be but I bet your bottom dollar that there's more to this than is made out.

 

[davesparks]

I can't think what it could be but I bet your bottom dollar that there's more to this than is made out.

If you can't come up with a way of connecting this that will cause the problem then why state that the problem is with the way if is connected ?

Random speculation doesn't help anyone.

 

[i=p/u]

short between live conductors when bird sits on roof.....

 

[ash_s3]

It's wired correctly as I installed it about 18 months ago.
Hager J804 in the loft, feed in, twin to pull cord, twin to spotlights and a 3c&e to TP fan isolator then onto the fan.
Fan is a Manrose MF100T, wiring hasn't been interfered with in the meantime.

 

[topquark]

Substitute the switch (or check the resistance across contacts in off position if you don't have a spare on you).

 

[Silly Sausage]

It's wired correctly as I installed it about 18 months ago.
Hager J804 in the loft, feed in, twin to pull cord, twin to spotlights and a 3c&e to TP fan isolator then onto the fan.
Fan is a Manrose MF100T, wiring hasn't been interfered with in the meantime.

Wire it with the Line and S/L on the outer cores, N in the middle.

 

[uksparks]

If you can't come up with a way of connecting this that will cause the problem then why state that the problem is with the way if is connected ?

Random speculation doesn't help anyone.

Sorry master Dave

 

[ash_s3]

Archy- You think it's picking up the voltage for the contacts inside the isolator?

 

[Silly Sausage]

Archy- You think it's picking up the voltage for the contacts inside the isolator?

Sorry, a bit vague there, I mean the cable.
May as well do the same at the isolator.

If it isn't already wired this way, give it a try and let us know the result...put us all out of our misery! :smilielol5:

 

[HandySparks]

Wire it with the Line and S/L on the outer cores, N in the middle.

Yep, worth a try.

 

[ash_s3]

Sorry chaps I'm not really following here.

Connecting the Line and S-Line opposite ends of the isolator - is this to keep the cores apart in the pattress?

 

[davesparks]

Sorry chaps I'm not really following here.

Connecting the Line and S-Line opposite ends of the isolator - is this to keep the cores apart in the pattress?

In the cable!

Do you understand how capacitive coupling works?
There are many threads on here discussing if if you search.

 

[ash_s3]

Ah I see now, so the N and E are in between the two Lines of the cable.

And no I'm not clued up on capacitive coupling, just youtube'd it and nearly slipped into a coma listening to the guy!

 

[davesparks]

Then read up on it and understand it before you go any further.

Then you can diagnose whether or not this is the problem and design a suitable soloution.

 

[ash_s3]

Will do Dave, thanks for your input.

 

[HandySparks]

Ah I see now, so the N and E are in between the two Lines of the cable.

Exactly. The permanent live will then tend to induce a little current in the N and the E (which you don't care about) rather than the switched L, which is further away on the other side of the cable.

 

[davesparks]

Exactly. The permanent live will then tend to induce a little current in the N and the E (which you don't care about) rather than the switched L, which is further away on the other side of the cable.

It won't induce, the phenomenon is capacitive not inductive

 

[HandySparks]

It won't induce, the phenomenon is capacitive not inductive

I'm using the term in its general sense, "Bring about or give rise to". What's the concise term for "to cause a current to flow due to capacitive coupling"?

 

[davesparks]

I'm using the term in its general sense, "Bring about or give rise to". What's the concise term for "to cause a current to flow due to capacitive coupling"?

When discussing electricity the word induce has a specific meaning, using it otherwise is only going to give rise to confusion.

I doubt there is a concise term, we are talking about a technical/scientific subject which is something that doesn't work well with shortening terms down for convenience

 

[Silly Sausage]

I'm using the term in its general sense, "Bring about or give rise to". What's the concise term for "to cause a current to flow due to capacitive coupling"?

I think in these cases, it's just a case of the circuit acting as a capacitor connected across an AC voltage source.
So it's just the 'natural' (high end terminology there!!!) current flow, in these cases in the order of micro Amps.
Which are starting to have a/or producing, odd effects on newer low power gear.

 

[Octopus]

This may, or maynot be helpful but....

Today I investigated a bathroom where the lights (LED's) stayed on when the lights were off!

So I removed the cover of the ceiling mounted fan...... and narrowly avoided being "drenched" by the build up of water (condensation) that had accumulated and clearly the moisture was providing the "connection" between the SL and L.

With the fan cover off, and the fan disconnected, the lights now work perfectly.

Hope this is of use to some of you!