Transformer in the ceiling light blew whilst it was turned on, we changed the transformer in the light, but now when the light is turned on at the wall there is no light and when the light is in the off position on the wall it lights up why has this happened.
Light switch reversed after transformer blew in the ceiling
- Thread starter picklepass
- Start date
the light switch is a double as one is the downstairs switch and the other is for upstairs landing, so would swapping the l1 and common still be ok to do
Which switch is it that is upside down - the one for the downstairs light or the one for the upstairs light?
If it is a 2 way switch (ie one that controls the upstairs from downstairs) then up is sometimes down and down is sometimes up.
If it is a one way switch for downstairs only then if there are only two conductors one red/brown in the C and one black/blue in the L1 then you can swop those.
its a single socket with 2 switches , the landing one is down sometimes as it is controlled by the upstairs landing switch aswell.
The other switch controls the living room light, that's the one that is down and off , seems like its been reversed
The other switch controls the living room light, that's the one that is down and off , seems like its been reversed
Am I missing something? Since when would swapping the connections to a one-way switch alter anything?
Kind Regards, John
So your solution to the OP's problem is?
No idea - but I do know (as I presume you also know) that swapping the connections to a one-way switch will not be a solution to any problem
We're clearly not being told something relevant. If all that has been changed is the transformer, and the switch has not been touched, then it's obviously impossible that the functioning of the switch could have changed. If it is a one-way switch, the only thing I can suggest is that the OP removed the switch for some reason and then refitted it upside down! As you've said, if it's a two-way switch, it could just be that someone has operated the other two-way one!
Kind Regards, John
Hi the only thing I hadn't said is that water from a leak went into the transformer light, so it popped when it was switched on so we ordered another transformer and then this happened. its exactly the same transformer as the original one in the light. The light switch was never touched. Does the switch have to be put back in the off position when renewing the transformer or wouldn't this matter 
No - and if the light switch was never touched, it really makes little sense that its function can have changed.Hi the only thing I hadn't said is that water from a leak went into the transformer light, so it popped when it was switched on so we ordered another transformer and then this happened. its exactly the same transformer as the original one in the light. The light switch was never touched. Does the switch have to be put back in the off position when renewing the transformer or wouldn't this matter
To be clear, is there just one switch which operates this particular light? If there were a second, it could just be that someone has operated it, thereby reversing the 'on' and 'off' positions of the switch you're talking about.
Kind Regards, John
Yes only one switch that operates tthe living room light . Its just strange . If the wires were wrong in the actual light in the ceiling it wouldn't work would it ?
It's very hard to see how anything to do with the wiring in the ceiling/light could affect how the switch operates. Are you certain that it's changed?
Have you looked inside the switch (with power off, of course) and, if so, can you remember how many wires (2 or 3) go to this particular switch?
Kind Regards, John
The only thing I can think of is that instead of the switch being in series with the 'transformer' primary, it has been mis-wired across the seconday, and the 'transformer' is actually a switch-mode power supply so is not destroyed by its output being shorted.
So where would the primary be getting its switched live from?
I was thinking that the primary is getting an unswitched live and neutral due to a wiring error.
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