Study lights flickering

[meerekat]

Hi

Looking for some assistance with my study lighting.
* I've attached a diagram of the layout at the bottom of the thread.

The problem started when the lights started to flicker, which then developed to virtually not being on at all - just random flickers of light.

I pulled apart the lights, switch, etc ... and can't find anything wrong, although have determined the power source is from the power socket circuit and not the lighting ring main.

Running a power meter on the light switch power feed it does fluctuate wildly, leading me to think its an ac feed.

Me not being an electrician I have the following questions:

1: From the diagram, the power feed into the light switch is in the following config;
Live into L, with out-going feed to lights in L1
The neutrals (incoming & outgoing) being grouped together in a terminal block
… is this ok? … as this has worked for some 2-3 years without issue!

2: Should there be an alternating current into a light switch?

3: Any idea what might be causing the lights to flicker?

It’s worth noting, since playing around with the lights they are not working at all now!
Power is not feeding from the switch to the lights :S


Thanks for any help you can provide.

Cheers
Meerkat
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[ban-all-sheds]

I've attached a diagram of the layout at the bottom of the thread.

No you haven't.

 

[riveralt]

Firstly, if you drawing is accurate, there should be a 3 Amp switch fused connection unit, preferably at the switch itself - there isn't.
Secondly, how are the lights connected together in series or parallel?
Thirdly have you checked the terminal connections at all the points in the circuit - you could have a loose or burnt out cable that has been causing the flickering.
If there are no problems here and you have a multi-meter check that you have continuity between each leg of the circuit -ensure the circuit is dead first.
If you feel confident and are competent and have a multi-meter then you should check that you have 240v at each stage of the circuit - beware this is a live test.
I would say do an insulation resistance test but I would doubt the diy mulitimeter will have such a facility.

 

[ban-all-sheds]

I pulled apart the lights, switch, etc ... and can't find anything wrong, although have determined the power source is from the power socket circuit and not the lighting ring main.

That switch should be a fused connection unit.

BTW - lighting circuits are not rings - you should spend some time here: //www.diynot.com/wiki/electrics:lighting

Running a power meter on the light switch power feed it does fluctuate wildly, leading me to think its an ac feed.

Well it is, but that's not why you're seeing fluctuating readings.

2: Should there be an alternating current into a light switch?

Yes.

• http://kevinboone.net/electricity.html
  
  
• http://web.archive.org/web/20080213...inboone.com/domesticinstallations.html[/list]
  
  
  

  3: Any idea what might be causing the lights to flicker?

  They are not getting a constant supply of electricity.
  
  
  

  Power is not feeding from the switch to the lights

  There you are then - if you have 230V at L1 and 0V at the lights there's something wrong with the cable from the switch to the lights.

 

[meerekat]

I've done continuity tests and get positive responses to all connections ...

 

[riveralt]

I've done continuity tests and get positive responses to all connections ...

Howe long is cable, what is it size and, after nulling your meter, what were the resistance values for R1 and R2? from the socket to the second light with no bulbs present and the light switch on.

 

[meerekat]

You might be on to something with ..
Quote: That switch should be a fused connection unit.

I've just a basic on/off light switch ... cuold that be the issue?

 

[riveralt]

You might be on to something with ..
Quote: That switch should be a fused connection unit.

I've just a basic on/off light switch ... cuold that be the issue?

Yes as I stated earlier you should have a 3Amp switched FCU at the switch point - 2.5mm2 T&E cable from the socket to the switch and 1mm2 t&E cable to the lights.
From your drawing it looks like the idiot who set this arrangement up didn't both with the cpc (earth) either - is this because the lights are double insulated?
Whether the lack of the FCU is an issue will depend on whether this arrangement has knackered the current switch.

 

[ban-all-sheds]

I've just a basic on/off light switch ... cuold that be the issue?

No.

That is, the switch itself could be knackered, but if so that's not because it isn't an FCU.

 

[EFLImpudence]

Put it this way -

If all the conductors have end to end continuity,
if all the connections are good and in the right place,

if the switch is good and connecting properly,
if the lamp-holders are good and connected properly
if the lamps are good and connecting properly and

if the power is on and the switch is closed then

The lamps will light.

In other words, check the above.

 

[meerekat]

ok, been over this again this morning ...

All connections are ok, continuity tests positive for all connections.
It's definitely the switch, confirmed no current passing through!

So with that in mind which switch is required? .. as there's been some conflicting recommendations.

- Do i need a fused switch?
- Does it need to be FCU

Many thanks
Meerekat

 

[EFLImpudence]

- Do i need a fused switch?
- Does it need to be FCU

Same thing.

 

[ban-all-sheds]

You can use a switched FCU in place of the switch, and it will work fine, but won't look as good as a normal light switch.

If you would rather you could put an unswitched FCU next to the socket and go via that to a normal switch. You should do that if the cable between the socket and the switch is small - do you know what size it is?

And does the cable have an earth?

Also, I don't know if your drawing reflects the angles the cables run at, but if they are concealed they are not in the right places: //www.diynot.com/wiki/electrics:walls