Flourescent light hum/buzz

[Ronob]

We have a 5ft flourescent light in our kitchen, about a month ago the light wouldn’t turn on, just a very dim glow each end of the tube. I changed the starter first, simply because I had one to hand, that didn’t do the job so I purchased a new tube which did work but was still a little slow at switching on, there would be one or two flickers before it sprung into life - perfectly liveable with.

last week however, it has started to hum, sometimes buzz, not every time it’s switched on, maybe every third or fourth time. I can only think that it has something to do with the box of tricks that lies within the casing. I’m not sure what that’s called so don’t know how to order a new one.

can anyone tell me if my assumption is likely to be correct, and what this box is called so I can buy one. It doesn’t seem difficult to replace which just a two or three wires.

oh and where can I buy one from? I’ve looked on tlc-Direct.co.uk and screwfix, but can’t find anything on either site

 

[cleggy]

are you sure you have replaced the starter unit with the correct size one.i replaced mine sometime ago with one i had handy and it struggked everytime to light although it did work.they have different ratings on them so make sure you have the correct wattage one.the lights do normally have a hum when on too

 

[flameport]

oh and where can I buy one from?

This: https://www.tlc-direct.co.uk/Products/FGCK58.html
although it's desperately unlikely that the existing one is faulty. It's just a big coil of wire on an iron core.

Failure modes would be open circuit in which case nothing would work at all, or shorted internally which would cause it to overheat and smoke until the insulation burned off, then there would be a big bang and it wouldn't work any more.

 

[bernardgreen]

Most common reason for hum / buzz in a magnetic choke is loose laminations ( thin sheets of magnetic metal ) in the magnetic core.

If the loose laminations are accessible then as a last resort a coating of epoxy resin can prevent them vibrating

 

[Ronob]

are you sure you have replaced the starter unit with the correct size one.i replaced mine sometime ago with one i had handy and it struggked everytime to light although it did work.they have different ratings on them so make sure you have the correct wattage one.the lights do normally have a hum when on too

I assume so, it was the same as the one I took out. As with most things these days when the last one was replaced way back when, I could only buy a replacement pack of two! So, I was determined to keep the second one rather than do what they’ll hope you’ll do - lose it so have to buy another twin pack!

 

[fluorescence]

Buy an electronic starter, this will; cure the slow starting problem, potentially DOUBLE the life of the lamp, ensure the lamp starts first time without repeated flashing, safely shut the lamp off when it dies and should last much, much longer than a traditional starter.

As for the buzzing, it's likely the buzzing is actually from the spine of the fitting around the ballast, this is quite common. Next time it buzzes, gently push a broom handle or similar on the spine and it'll stop buzzing if this is the issue.

Ebay link to a suitable electronic starter (UM2): https://www.ebay.co.uk/itm/ELECTRON...947627?hash=item23ba916aeb:g:-9AAAOSw-EBZp9vj

 

[Ronob]

Buy an electronic starter, this will; cure the slow starting problem, potentially DOUBLE the life of the lamp, ensure the lamp starts first time without repeated flashing, safely shut the lamp off when it dies and should last much, much longer than a traditional starter.

As for the buzzing, it's likely the buzzing is actually from the spine of the fitting around the ballast, this is quite common. Next time it buzzes, gently push a broom handle or similar on the spine and it'll stop buzzing if this is the issue.

Ebay link to a suitable electronic starter (UM2): https://www.ebay.co.uk/itm/ELECTRON...947627?hash=item23ba916aeb:g:-9AAAOSw-EBZp9vj

can I use an electronic starter to replace the old ‘choke’ type? My light is quite old and is a single tube about 25-30mm diameter

 

[fluorescence]

The electronic starter is just a straight replacement for your glow bottle starter switch, it works in conjunction with the existing ballast etc. The starter I linked to works with any tube from 6" 4w T5 up to 8' 125w T12.

 

[FrodoOne]

You could replace the 1500 mm fluorescent tube with a LED tube, do away with the buzzing ballast/choke and save about half the electricity cost for the lighting from that "luminaire".

Even better, you could replace the existing "fitting" with a LED "panel". However, that would cost quite a bit more!

 

[Ronob]

Ok guys thanks for all your input. I will try the electronic starter, as recommended, and see how I go

 

[winston1]

You could replace the 1500 mm fluorescent tube with a LED tube, do away with the buzzing ballast/choke and save about half the electricity cost for the lighting from that "luminaire".

You forgot to add that it would also have half the output.

 

[FrodoOne]

You forgot to add that it would also have half the output.

However, the light generated would mainly come downward (instead of almost half being dispersed upwards into the fitting, where very little is reflected downwards.)

In practice, when doing a comparison while replacing two identical fluorescent tubes one at a time, I have found no discernible difference in the "utility" of the LED tubes, as compared to the relatively new fluorescent tubes which each replaced.

Also, fluorescent tubes fade over time and it is usually not until one of a pair (or more) is replaced that one realizes how much light is now not being produced, although the electrical cost is still the same.

 

[winston1]

With fluorescents lots of light is reflected from the ceiling and thus reduces shadows, something that was considered important 30 to 40 years ago.

LEDs can fade as well but I think it takes a lot longer.

 

[securespark]

Lighting that minimizes shadow has always been important, especially for task lighting.

 

[fluorescence]

Also, fluorescent tubes fade over time and it is usually not until one of a pair (or more) is replaced that one realizes how much light is now not being produced, although the electrical cost is still the same.

Not quite accurate. Old halophosphate lamps used to fade badly at the end of their lives only retaining something like 50-60% of their original lumens at end of life (EOL). Modern triphosphor lamps retain nearly 90% of their original lumens at EOL. Triphosphor lamps simply colour shift as they age, a 4000k lamps becomes more like 3500k at EOL, but in the vast majority of situations this is not an issue.