Individual lights pop without 'fusing'

[aroundM21]

What would cause individual lights in a multi-light fitting to cease working ??

Obviously I don't mean Bulbs blowing - replacing bulbs demonsrates the individual fitting has broken, yet other lights in the same unit work. Now happened with different light fittings - so I don't think I just got a dodgy light unit.
It does not break the MCB / RCD when it happens.

I have:
- an extension which takes its 2 lights by extending a single light leg (I don't believe it is part of a ring, though cannot be sure).
- in addition to the original 3-bulb unit (standard 40Ws), the extension has 2 Quadrupple 50W Halogens.
Could I be overloading it ? (50*4*2 + 40*3 = 400+120 = 500W on a single wire)
- An MCB breaker (ie fuse-board replacement trips). All House lights are on a single 'trip', and it is not effected when we notice a light has popped - ie it does not trip.

Even though it's not causing Trips, I looked for dodgy connections but didn't see any, so without removing ceilings I'm stuck for ideas.
I could buy new fittings and try fewer bulbs (ie over-loading theorey) but even if that is the problem it won't tell me the acceptable limit without blowing my 3rd light fitting, and I'd prefer to save the money if possible !

Thanks in advance - Mike.

 

[PrenticeBoyofDerry]

What type of lights are these, are sure there are no transformers in the circuit and the lamps are not 12V?
If it is a single fitting with three lamps, there could be a loose connection in one or two of the legs.
If you were overloading the circuit the MCB should trip out.

 

[aroundM21]

Certainly no Transformer in the House-wiring : so 240-250 V (and I believe 5 Amps for lights not plugs).
I don't believe there are transformers in my latest light fittings - but to be explicit, they are 50 Watt Halogen Bulbs - just spotted "240V" on the side of one.

If it was a loose connection, why would it blow the light fittings, not just make them work intermittently ?
Of course FINDING any loose connection or similar is where I'm fearful of having to take down a ceiling and wall in my search ...

Thanks for the quick response.

 

[PrenticeBoyofDerry]

edit/delete

 

[PrenticeBoyofDerry]

Certainly no Transformer in the House-wiring : so 240-250 V (and I believe 5 Amps for lights not plugs).
I don't believe there are transformers in my latest light fittings - but to be explicit, they are 50 Watt Halogen Bulbs - just spotted "240V" on the side of one.

So if they are 50W GU10's they will be mains voltage 230V and transformers should not be in circuit.

If it was a loose connection, why would it blow the light fittings, not just make them work intermittently ?

Not sure I understand you, the circuit has not tripped and the lamps(bulbs) are new. You have power to the fitting as at least one lamp (bulb) works, so you have fault within the fitting, this could be the lamp holder or a loose connection. The fuse would blow if you had overload, short between line and neutral or fault between live and earth.
Are you sure the lamps (bulbs) are turned tightly to the lamp holder?

Of course FINDING any loose connection or similar is where I'm fearful of having to take down a ceiling and wall in my search ...

If some lamps (bulbs) on each fitting are working, the fault will not be within the ceiling void but at the fitting.
That's if I have understood what you have described?

 

[bhm1712]

im not sure what the OP is on about.

What do you mean: 'Obviously I don't mean Bulbs blowing - replacing bulbs demonsrates the individual fitting has broken, yet other lights in the same unit work'

This makes no sense at all. Is the fitting broken, or has the lamp (more commonly known as a bulb) failed?? or do you mean that individual lamp sockets on the fitting have failed even though some of the others still work??

How does a bulb blowing demonstrate that the fitting is broken?

Where did you buy the lamps? I bought a load from a certain shop with a blue and yellow logo which when fitted only lasted about 7 days before i had to replace the lamp. They were halogen gu10

 

[aroundM21]

Bhm -ok using your terminology, I mean I've tried multiple bulbs (lamps) in multiple positions. Swap a working bulb & a dim one and the same socket is lit and is dark.

So I mean the sockets within the overall unit (fitting) are being blown-out somehow.

 

[securespark]

Dim one????

Can you explain?

 

[RF Lighting]

Sounds like faulty GU10 holders on cheap chinese light fittings

 

[PrenticeBoyofDerry]

Is this a new fitting or has this fault happened over a period of time.
If new take it back and replace.
If it's an old fitting it could be possible to replace the lamp holder