Discuss 3 gang switch - one light not working in the Electrical Forum area at ElectriciansForums.net

M

minstercourt

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:  American Electrical Advice Forum

Hi, im a newbie here, so please excuse me if any mistakes in my post. i have a 3 gang switch on our living room. in them three switches on switch is used for the living room light which works fine, another switch is a two way switch which operates the stairs light which has the other 2-way switch is upstairs, even that one works fine. the third switch is for the light outside the house, which is not working. i have changed the bulbs, holders and i have checked the current passage with a tester and its getting the power but still doesn't work. if i use the same bulbs and holders some where else it works. can you suggest me, how can i sort this out. i am adding a picture of the switch connections to this thread, i think its not clear but let me know if you need some more detail. Thank you for your help.
 

Attachments

Aico Carbon Monoxide Detectors
This official sponsor may provide discounts for members
J

johnnyb

  • Thread Starter Thread Starter
  • #2
Sounds like you have a possible neutral fault my friend, is the tester you are using, one with proper leads on it, check at the light fitting Live to Earth and Live to Neutral, if the tester lights up on both then it could be a faulty lampholder, the pins are they actually touching the bulbs when you put them in. Are you 100% sure there is voltage going the the light switch, again check live to earth.
 

sparks1234

-
Arms
Looking at the picture they have used the blue on a 3-core as a neutral down to the switch, can you either put a proper test meter across the switched side and the neutral in the connector block, see if that gets a supply, if not try across the live / neutral this would prove the switch.
 
4

4x4 mark

  • Thread Starter Thread Starter
  • #4
has the light ever worked or is it a job you are looking at that you have no history with.
is the light controlled by a photocell or pir that could be at fault look for things like this as its very unusual for a switch to stop working.
 

EddieB

-
Arms
Looking at the Picture it looks as if the Neutral for the outside light is sitting in connector block . I can see bare copper at this connector is the connection good and tight. If it was me I'd check that this is a neutral ensure that you have 230v between the live feed and the connector block and take it from there. I had a light fitting recently that was a Es type and the contacts inside the lampholder were out of shape and consequently did not touch the lamp contact points
 
M

minstercourt

  • Thread Starter Thread Starter
  • #7
Update: Thanks for the replies, as eddieb said, the neutral was not connected. i don't know why the neutral from this switch and the neutral from the second switch has not been connected to the gang switch, but they connected together. so i have taken out the black colour neutral and connected where the blue colour wire is connected on gang switch, bingo its working but the light is flickering, i have put a new energy saving bulb, even that is flickering. i don't know, may be the neutral wire is not very good. suggest me if i can do anything. thank you.
 

EddieB

-
Arms
Dont do that, take the black back out of the switch , the neutrals are not to be switched. I would recommend that you disconnect all the wires from the switch and work your way through them seperating the feed (s) from the switch lines, identify each cable as to what it does. You will probably have 1 live and neutral coming into the switch the red that is linked across the back of the switch will be the live see if the accomponing blue or black is the neutral I would suspect that it is, you need to identify the cable going out to the outside light, the red will be your switch line your black or blue will be connected to the incoming neutral
 
M

minstercourt

  • Thread Starter Thread Starter
  • #9
Thanks for the quick reply but im not sure how to connect a 3 gang switch so i won't be able to take all wires out and connect them again, like you said i might be able to find out the live and neutral coming in to the switch and try to connect the outside switches neutral to the one coming in and see what happens,, im at work now so will let you know tonight. thank you for your advice again.
 
M

minstercourt

  • Thread Starter Thread Starter
  • #10
Hi there, i have checked the switch, the incoming neutral is connected to the switch that's where i have connected the neutral of the outside light. i have noticed one more thing when i connected this, if i switch on the 2-way switch the outside light switches off even the switch is on. if the 2-way switch is off then the outside light is blinking. i don't know how to solve this, instead of this can some one explain me how to connect the 3 gang switch with the following connections.
1. 2-way switch for a light
2. 1 light in the living room
3. 1 light for outside the house.

Thanks for your help.
 
B

bazza2541

  • Thread Starter Thread Starter
  • #11
Does the action of the switch seem 'sticky'? If so it may be a faulty switch, like any mechanical device they have a life and might need replacing.
If you look into the back of your switch you will see a bunch of screw terminals. They are seperated into threes in the shape of a trinagle, one at one end usually marked common and two at the other end usually marked L1 and L2.
Fot the 1 Light in the living room, you should have the permanent live (switch feed) going into the common terminal of 1 switch and the wire going back to the light (switch wire) going into L1.
For the 2 way switch you should have the strappers going into L1 and L2 and the switch wire going into the common terminal.
For the outside light you should have the switch feed going into the common terminal and the switch wire going into the L1 terminal.
On the photo it shows that you do not have seperate switch feeds and that one common is bridged out to the next, this is standard practice and nothing to be concerned about.
A quick way to prove the wiring to the outside light is to disconnect the blue and black wire from the connector block in the switch and then turn the outside light on with the bulb in place. If you can detect a voltage in the neutral wire, it means that the wiring, bulb and switch are good.
 
J

john2509

  • Thread Starter Thread Starter
  • #12
To me it sounds like the problem here is the connector block and it not being a neutral. It looks to me, forgive me if I'm wrong, that the connector block is part of the two way circuit. Is the switch controling the outside light the one on the right in the picture, if so, is it just a single red connected in the switch, ie has the black been cut off or is it the black going into the connector, i cant quite tell from the picture
 

EddieB

-
Arms
The Neutral must not be switched,
if you look at the back of the sw you will see 3 terminals per switch ie 9 possible termination points. each switch will have a terminal marked common L1 & L2 with the 2 way switch connect it looks as if you have a 3 core connect the red to the common and the yellow and blue (with the red sleeving on) to L1 and L2 of the 1st switch, The next set of 3 terminals is the 2nd switch you have a loop feed between the common of switch 2 and the common of switch 3. the yellow is the switch wire of the 2nd switch which goes into either L1 or L2 of Switch 2. The remaining red is the outside light switch line and goes into L1 or L2 of switch 3. The remaining Blue and Black are twisted together and put into a connector block, Job done!!
 
M

makawhite

  • Thread Starter Thread Starter
  • #14
Hi

This might be off the topic a bit but... say during the installation normal T&E was used for the 2nd switch instead of 3 core would you then make a bridge from com1 to com2 then to com3, phase of switch 2 to L1 and Neutral of switch 2 to the choc block. In other words

Switch 1: Red to Com, yellow to L1 and blue to L2.

Switch 2: (using T&E) bridge from com in switch 1 to com in switch 2, brown to L1 and blue to choc block.

Switch 3 bridge from com of switch 2 to com of switch 3, red to L1 and black to choc block.


I'm studying at the moment and just trying to get my head around everything!

Cheers
Mark
 

Reply to 3 gang switch - one light not working in the Electrical Forum area at ElectriciansForums.net

Bulk Workwear - Clothing Suppliers for the Whole Forum Network
This official sponsor may provide discounts for members
Top Bottom