How To Add A 1 Switch Light Circuit To A 2 Switch Existing Circuit

[formulaoz]

I have done this using a 4 gang block but have found that the the original light glows dimly when I manage to switch the new fluorescent light on via its one switch.  I wish to use the lights independantly but there is some appears to be leakage to the original light.  A simple circuit diagram would help me. Thank you in advance.

 

[Zeespark]

Can you take a pic of the connections at the rear of the lightswitch and also the connections at the light at all?

:Welcome:

Andy Guinness

 

[Andy™]

most likely caused by inducatance from cables running close by. fit something with a filiment or a resistor and the problem will go away

 

[Doc Hudson]

What type of lamp is in the new light fitting? As Andy said induced voltages can cause low energy lamps & LED's to glow when off. In which case you may need a snubber in the circuit. Alternately you may have wired two lamps in series not parallel. It may be best if you could do a drawing or take a photo of what you have done so far. One of the Admins will hopefully change your status to allow you post images even though you have a low post count. Welcome to the forum.

Doc H.

 

[formulaoz]

Thank's for your prompt replies.  Will take some pictures tomorrow 9th October.  The new light comprises small dual fluorescent tubes.  The original light is old type incandescent bulb.  Am pretty sure I linked the new one in series.  One other point is that I cannot turn both lights on at the same time.  This is not a problem as I do not need to.

 

[kerching]

I think you may have answered your own question.  They shouldnt be in series.

all will become apparent when we see the pics tomorrow

 

[formulaoz]

Unfortunately I cannot find a way of including a photo possibly as this is my first post.  Can an administrator please waive this restriction so that I can include some pictures?

 

[a3]

Unfortunately I cannot find a way of including a photo possibly as this is my first post.  Can an administrator please waive this restriction so that I can include some pictures?

Try Now.

Use the more reply button for the upload options.

 

[formulaoz]

This attached diagram shows how I wired the new light in.  Hope that helps.  Just to repeat, the new light is a small twin fluorescent and the existing one is an incandescent bulb.  Please note that the incoming feed line has a fourth cable (probably to enable dual switching on the existing circuit).  This is not shown on the attached diagram.  This yellow cable remains connected to the dual switches.  Hope this makes sense.

 

[Doc Hudson]

Is this drawing the new lamp connection you have added or the original light? If there is another 'unshown' yellow wire then I also assume one of the wires you have shown as black is actually Blue? If so then this Blue is probably also a live wire for the two-way switching you referred to, not a neutral wire. A three core and earth between the two switches may not have any neutral wires in it at all. Which could account for your incorrect operation. Can you post a picture of the whole arrangement, both lights & all switches to get a better understanding of where your problem may lie? 

Doc H.

 

[formulaoz]

Attached are the pictures as requested. Due to their size will attach two with this post and two with a following post.

The schematic distribution block I posted previously showed a lamp.  That lamp is my new fluorescent tube controlled by a new single circuit switch which I think is fitted in series?

Just to refresh, The new light will not turn on when the incandescent 2 way switch one is on. (Not a problem as I don't need them both on).

But, when I turn the new fluorescent lamp on via the new 1 way switch, the incandescent one shows a low glow even though it is supposed to be off. Not really a problem but should not happen.

Thanks for your help so far.

Remaining two pictures showing the 2 way switches.

 

[NozSpark]

Did you cut into the red/yellow/blue cable to add this extra light and switch?

 

[steptoe]

the red of the 3core 'may not' be the permanent live,

it 'may' be the blue, you need to check this.

 

[NozSpark]

the red of the 3core 'may not' be the permanent live,

it 'may' be the blue, you need to check this.

....but if he's tapped into the strapper????????

 

[steptoe]

....but if he's tapped into the strapper????????

there appears to be a seperate live into the switch then a different switch wire to the fitting on the strappers,

pic 3

 

[SPECIAL LOCATION]

You haven't got a neutral connection to your new switch!!

from looking at your photos..

original light was wired like this..



look closely at the Red Yellow and Blue wires between the two way swicthes..

THEY ARE ALL LIVES...

the neutral connection is in the two black wires in the terminal block at the first switch!

You have added on something like this...



which if the follow the path from live..

down the red wire to your new brown and then new swicth..

From switch through blue then brown to new light...

then from light via Blue to new box then to first switch then to red to original light..

then finally after passing through the original light as well finally get to a neutral!!!

Both lamps are in series...

AND.. Both are glowing dimmly...

I guess you haven't actually seen the new lamp working at full voltage yet..

They need to be in parallel!!

You need to get a neutral wire to your new lamp and disconnect from the blue live strapper between the two way switches.

Can I hazard a guess that no test equipment has been used during this work to verify any cables??

 

[steptoe]

You haven't got a neutral connection to your new switch!!

from looking at your photos..

original light was wired like this..

DRAWING1.JPG

look closely at the Red Yellow and Blue wires between the two way swicthes..

THEY ARE ALL LIVES...

the neutral connection is in the two black wires in the terminal block at the first switch!

You have added on something like this...

DRAWING2.JPG

which if the follow the path from live..

down the red wire to your new brown and then new swicth..

From switch through blue then brown to new light...

then from light via Blue to new box then to first switch then to red to original light..

then finally after passing through the original light as well finally get to a neutral!!!

Both lamps are in series...

AND.. Both are glowing dimmly...

I guess you haven't actually seen the new lamp working at full voltage yet..

They need to be in parallel!!

You need to get a neutral wire to your new lamp and disconnect from the blue live strapper between the two way switches.

Can I hazard a guess that no test equipment has been used during this work to verify any cables??

well spotted,

I guess I should have seen that as I saw the blue as a possible perm live,  :|

 

[SPECIAL LOCATION]

well spotted,

I guess I should have seen that as I saw the blue as a possible perm live,  :|

From the ops report of the symptoms....

When the original light is on the new one WONT turn on...  

All strappers @ 230v

But when original is off new one works but with dim glow... 

Red & possibly yellow @230v..

Blue @ neutral + resistance of incandescent lamp!

The only way I can see the symptoms matching the wiring photos.

Attached are the pictures as requested. Due to their size will attach two with this post and two with a following post.

The schematic distribution block I posted previously showed a lamp.  That lamp is my new fluorescent tube controlled by a new single circuit switch which I think is fitted in series?

Just to refresh, The new light will not turn on when the incandescent 2 way switch one is on. (Not a problem as I don't need them both on).

But, when I turn the new fluorescent lamp on via the new 1 way switch, the incandescent one shows a low glow even though it is supposed to be off. Not really a problem but should not happen.

Thanks for your help so far.

Remaining two pictures showing the 2 way switches.

See post #16...

But also to quickly verify if my assumption is corrrect..

take the incandescent lamp out..

I think you will find your new lamp also stops working as no neutral connection.

 

[formulaoz]

Thanks for all your replies, will take the fluorescent light out and see what happens.  Then I will call an electrician.  Thanks again.

 

[formulaoz]

I removed the incandescent light and the new one would not switch on as you predicted, congratulations on understanding the wiring pictures and deciphering my conundrum. 

Not sure what to do now (I definitely do not wish to have both lights on at once). 

I have located the supply to/before the 2 way circuit so should be able to connect the new switch to that line and run the new lamp in series after removing some of the wires at the connection block that are needed.

PS: As I am new to the forum, how do I reply directly to a specific post.