Ceiling fitting buzzing

[IJWS15]

Daughter has a 3 lamp (G9 240V) ceiling light which is buzzing.

Checked and no loose connections. Loose from the ceiling it does not buzz, connected to the ceiling it does.

Have taken it down, checked and re-fitted, no difference.

Any suggestions to stop the buzzing?

 

[Taylortwocities]

Got a wasp in there, maybe?

Seriously though - do you have a dimmer on the circuit? I've often heard transformers buzzing if there's a dimmer but not a G9 - its 230V.

If you've got a dimmer, bypass it and see if the buzz stops.

 

[IJWS15]

No wasp

No dimmer

No transformer (240v lamps)

There are some crimped connections in the base (done by the manufacturer) - they seem tight as well.

If I hold the three metal branches which carry the bulbs it stops but all the connections are tight and the branches also have braces between them about 8" away from the base.

 

[securespark]

Some kind of vibration set up by harmonics?

 

[Steve]

Some kind of vibration set up by harmonics?

In which case a dimmer may help

 

[Taylortwocities]

Harmonics eh, like this??

Is this coming from a specific part of the fitting or from the whole thing?.

 

[securespark]

Thinking more like this:

 

[IJWS15]

I have looked and Larry Adler is not hiding in the loft. I was up there to move a transformer on one of the other lights (another room and about 15 feet away.

Seriously where would we be getting harmonics from? It is a 2 bed flat, first floor so we have access to the loft (that the ground floor flats do not have). Only single phase 230v supply and it is nowhere near the aerial leads for the communal satellite system - about 20 feet away.

Lighting circuit is looped at switches and not ceiling roses if that has any bearing - wiring probably standard with ground floor where they do not have access from above.

Will try a dimmer switch (one from home if it can handle 3x40w which is what I think the lamps are) and see if it makes any difference.

 

[IJWS15]

Taylortwocities

The light is stainless steel(?) and has a round base about 4" in dia . In the centre there is a stainless cylinder about 2" long projecting from the centre with the three pairs of light wires down the centre. THere is then a cap on that with the three branches (each about 5mm dia) coming out of its top (flat surface) - I know , a picture is worth . . . . .

These branches are about 10" long and spread out. There are three diagonal braces, between the light stems of the same section as the stems and welded/brazed on.

The bulbs (sorry lamps) have glass screw on shades.

The fixed wiring from the ceiling is connected through a 3way choc block to the L-N-E that were provided by the lamp maker. The earth is under the nut that holds the cylinder onto the base, L and N are each about 2" ling and each are crimped to three thin wires that go down the three branches to the lampholders in pairs.

The vibration is coming from the top of the branches just where they join the cylinder.

Taking the shades of makes no difference.

Pushing a back box gromit (well it was the only bit of rubber I had on me) into the centre where the branches come together stops it but she told me I was not leaving it like that! Just doesn't appreciate how much I am saving her on electricians visits!

All the connections and joints on the light assembly are tight.

Got me baffled.

Idea - must check the live-neutral for continuity with the bulbs out! Did check there was no voltage on the case but did not check L-N.

 

[securespark]

Larry Adler???

I'll have you know that's Fats Waller!

Does it vibrate when switched on but with the lamps out?

What about with a different lamp, a CFL, maybe?

 

[regsmyth]

How about it being a little bit of swarf inside one of the tubes - ie not an electrical buzz at all?

 

[Taylortwocities]

Now you are being silly. you'll never get one of these in there

 

[plugwash]

this may sound like a stupid question but does it only buzz when it is turned on?

 

[securespark]

Does it vibrate when switched on but with the lamps out?

No answer yet.

 

[IJWS15]

Yes - it only buzzes when it is turned on.

It is at my daughters flat and I have not been down there since Wednesday - will check the other questions over the weekend.

Have not checked it with the lamps out, they are too hot to touch when it has been on!

I was thinking that it could not be a live-earth fault as the breaker would trip but the lighting circuit is not on the RCD and the fault may be low current and hence not tripping the 6 amp breaker.