Flickering lights (am I using the correct thickness of wire?)

[kreatiff63]

Using a tuturial from a college lecturer, I've installed 2 way lights in our hallway. The cable I've used is 1mm lighting flex (2 core). The process I've used is taking the power to the switch. So I've used the permanent line from a neighbouring switch (4 gang) and connecting this to L2 where it joins with the cable I'm sending through to the other switch. I'm also passing the neutral direct (linked) to the light. The permanent line is then taken from L1 up to the light. I'm using 3 core for the switching between the lights.

The first thing I did was detach the second spot light, as this used 1.5mm wires. I read that using different cable strengths can cause flickering.
The second thing I did was try using another source but the flickering remained

So the question is with the flickering, should I be using thicker cables at then switch?

 

[Marvo]

Cable size differences will not cause flickering. You should size your cables according to their method of installation and according to the size of the over-current protective device in the CU.

Are all the lights flickering when they're on or just some?
What type of lights are they?
Are there any dimmers anywhere?

 

[kreatiff63]

Cable size differences will not cause flickering. You should size your cables according to their method of installation and according to the size of the over-current protective device in the CU.

Are all the lights flickering when they're on or just some?
What type of lights are they?
Are there any dimmers anywhere?

The light is a pair of spots but I've disconnected the second completely from the first spot light. The light is LED and was working before I moved the switches (set of 4) from the old location the new. So its just a single light at the moment.

 

[James]

Check all connections are sound.
it would not be the first time a cable has slipped out or to the side of a screw terminal.
check voltage at fitting when light is on, is it stable or changing.
if it is changing (L to N) is it the same when measuring L to E?

 

[kreatiff63]

Check all connections are sound.
it would not be the first time a cable has slipped out or to the side of a screw terminal.
check voltage at fitting when light is on, is it stable or changing.
if it is changing (L to N) is it the same when measuring L to E?

Thanks I'll check this out, I was also wondering if it was the thickness of wire, using 1mm to the light switch instead of 1.5mm? Or should I use 1.5mm as my linking wire from the power source to boost the supply? If thats how it works?

 

[DPG]

Thanks I'll check this out, I was also wondering if it was the thickness of wire, using 1mm to the light switch instead of 1.5mm? Or should I use 1.5mm as my linking wire from the power source to boost the supply? If thats how it works?

The cable size is not causing the flickering.

 

[kreatiff63]

The cable size is not causing the flickering.

Thanks for that, I did check the firmness of the connections on installation, but I may not have trimmed the covering back enough. I think the methodology is sound enough, the guy is a college lecturer and does tutorials for electrical qulaifications too. So it something I'm doing. I'll check the current at source and to the light.

 

[kreatiff63]

Cable size differences will not cause flickering. You should size your cables according to their method of installation and according to the size of the over-current protective device in the CU.

Are all the lights flickering when they're on or just some?
What type of lights are they?
Are there any dimmers anywhere?

I've measured voltage at the light switch and strangely I had different measurements, but the wrong way round for the light that is showing the flickering. Just to recap I have a 4 gang switch, and I'm taking power from the two switches which I know work - the outdoor lights and security lights. The power I was using for the hall lights was coming from the 2nd switch, and was going to L2. The measurements I had for the 1st switch was a wandering 199 - 220, the measurement from the 2nd was a steady 197. You would suspect that the wandering voltage of the 1st switch would be the one causing the flickering, but I was connected to the 2nd switch, which makes me think that the current is too low at 197?

 

[James]

these all seem low, what are you measuring between?

 

[kreatiff63]

these all seem low, what are you measuring between?

I'm using the terminals on the back of the switch and placing the red/black prongs on the screws holding the wires on COM and L2 terminals

This image shows the device I'm using for measuring the voltage at the switch


This image shows the back of the two switches I'm using.

 

[James]

That will not give you the voltage at the switch, it gives you the voltage across the switch.
word wise, it seems like a subtle difference but it makes a difference.

with the method you are using, you should measure 0v across the switch when the light is on.
the voltage measured with the light off is not relevant.

to measure the voltage available at the switch you need to be measuring from a live to a N or earth.

Note: the quality of workmanship on that switch and connections leaves a lot of room for improvement.
bare cpc wires (earth) should be sleeved with a minimum amount of copper showing, they should all be connected together not joined where it seems convenient.

 

[kreatiff63]

That will not give you the voltage at the switch, it gives you the voltage across the switch.
word wise, it seems like a subtle difference but it makes a difference.

with the method you are using, you should measure 0v across the switch when the light is on.
the voltage measured with the light off is not relevant.

to measure the voltage available at the switch you need to be measuring from a live to a N or earth.

Note: the quality of workmanship on that switch and connections leaves a lot of room for improvement.
bare cpc wires (earth) should be sleeved with a minimum amount of copper showing, they should all be connected together not joined where it seems convenient.

"little to be desired" ...will be improving the wiring - I'm in 'testing' mode with the method as I'm using this for the kitchen lights too but will tidy it up if it works.

Continuing with the suggested tests at the light tomorrow

 

[kreatiff63]

That will not give you the voltage at the switch, it gives you the voltage across the switch.
word wise, it seems like a subtle difference but it makes a difference.

with the method you are using, you should measure 0v across the switch when the light is on.
the voltage measured with the light off is not relevant.

to measure the voltage available at the switch you need to be measuring from a live to a N or earth.

Note: the quality of workmanship on that switch and connections leaves a lot of room for improvement.
bare cpc wires (earth) should be sleeved with a minimum amount of copper showing, they should all be connected together not joined where it seems convenient.

I've measured the power at the light and the figures swwing wildly between anything from a min 0 - 100 to a max 1500. The setting on the device i use to measure is at 800, so not sure if thats got something to do with it. I'm going to reset all the connections at the light, and attach the 2nd spot as well. I alos tried a new spot in there and this made little difference, if anything was slightly shallower the flickering.

 

[kreatiff63]

That will not give you the voltage at the switch, it gives you the voltage across the switch.
word wise, it seems like a subtle difference but it makes a difference.

with the method you are using, you should measure 0v across the switch when the light is on.
the voltage measured with the light off is not relevant.

to measure the voltage available at the switch you need to be measuring from a live to a N or earth.

Note: the quality of workmanship on that switch and connections leaves a lot of room for improvement.
bare cpc wires (earth) should be sleeved with a minimum amount of copper showing, they should all be connected together not joined where it seems convenient.

Another update... so I've tried the old spots, none LED, and these don't flicker. My wife has remembered that the guy putting in the spots for us originally had said that they wouldn't work with LED. So there's an interesting development too.

 

[kreatiff63]

That will not give you the voltage at the switch, it gives you the voltage across the switch.
word wise, it seems like a subtle difference but it makes a difference.

with the method you are using, you should measure 0v across the switch when the light is on.
the voltage measured with the light off is not relevant.

to measure the voltage available at the switch you need to be measuring from a live to a N or earth.

Note: the quality of workmanship on that switch and connections leaves a lot of room for improvement.
bare cpc wires (earth) should be sleeved with a minimum amount of copper showing, they should all be connected together not joined where it seems convenient.

So... weird happenings. The single LED was flickering, I added the Halogen light and this stopped the flickering. I then added the second spot and then I just had a weird soft glow on the second light and nothing on the first. I switched out the Halogen lights for LEDs and they both worked and also spotted I'd wired the first the wrong way round . Then the only thing different was the use of three triple connectors at the first light, and using the third wire to cut down the number of cables going to the light fitting to ensure that I had a good connection to light fitting. So weird allround, but the lights have settled down. Probably the resetting of the connection to the first light made the difference. I get a slight wobble when switching the 2nd light switch on/off. I read somewhere that that could be the switch connections or switch itself struggling. But all good in the end. Verdict - connections at the light causing the flickering, even with a single cable at the first attempt. ** And have sleeved the earth cables.

Thanks for everyones support. @James + @DPG + @Marvo