Dimmer Switch Problems - Is it safe?

[np1664]

Found the transformers, they are screwed into the cross joists in the ceiling/floor above. Each of the downlights has one. Can't get access to them through the downlight hole though.

I would like to replace with mains lights (probably use megaman GU10 energy saving bulbs).

Is it as straight forward as taking the two wires that run into each transformer, connecting a new GU10 fitting directly to these (8 downlights in all) and replacing the dimmer switch with a standard on/off switch?

I guess I may need to change the chrome ring surrounding the hole as I tested one of the megaman bulbs and it does not fit the present hole.

thanks

np1664

 

[securespark]

Yes, but the LV cable may not reach the GU10 fitting...

MY guess is that you have maybe the dimmer is mullered, so change it for a plateswitch anyway to see if you can in the meantime get the SELV lamps going.

 

[np1664]

If the LV cable does not reach the GU10 fitting, can I not just add in a small extension LV via a terminal block?

2 lights out of the 8 are working, albeit they flicker, hence why I thought the dimmer switch itself was okay, however I have a spare on off switch and will try this to see if the other 6 downlights start to work.

thanks

np1664

 

[ban-all-sheds]

A contentious issue is mains against LV d/l's, FWIW i don't think theres a lot in it and i always fit mains unless LV is actually needed (less bits to go wrong without transformers)

The IEC definitions of voltage bands are:

• Extra Low Voltage: AC below 50V and DC below 120V
• Low Voltage: 50 - 1000V AC or 120 - 1500V DC
• Medium voltage: 1kV - 35kV
• High voltage: 35kV - 230kV
• Extra-high voltage: >230kV

This is not some pedantic technical point - in regulations etc you'll come across references to "Low voltage", and it'll be no good you thinking that that means 12V...

 

[Steve]

If you want to fit megaman energy savers, you must buy fittings that have a flylead to connect the lamp and are open-backed, or those which are designed for CFLs.

 

[np1664]

Just to summarise .... we have 6 out of 8 downlights out and a number of excellent suggestions as to the cause and best way forward.

Today I replaced the dimmer switch with a simple on/off switch. The 2 working lights came on full brightness, the other 6 did not come on at all.

Does this confirm the 6 transformers are shot?

If so I need to make the decision to change the 6 transformers - this will entail lifting carpet and floorboards up in 3 separate rooms upstairs!!!!!! I will also have to match the dimmer switch more closely to the transformers to prevent this happening again in the future.

Second option is to convert to mains and possible fit megaman energy savers and have a simple on/off switch. again access via upstairs floorboards would be needed and new fittings and connectors.

any suggestions as to which way is best/easiest/cheapest? could I do either option myself or is it best done by a qualified electrician?

thanks

np1664

 

[slup]

You need to follow the cables and see where they go. A loose connection on one transformer / junction box could cause all the lamps after that one to go out. First place to check is the wiring to the two that are working as the problem could actually be there.

 

[Steve]

cheapest in every way in the long run is megamans.

cheapest right now (and the same amount of work) is new transformers.

 

[smitch83]

if you change to gu10 (230v) all the floating connector blocks you have mentioned will need to be enclosed in a choc box (should really be any way with 12v to prevent cable strain) and gu10 downlights should now really be earthed and most now come with an earth screw on top, if you replace the transformers you should really relocate them next to each light so they will be accessable from below without ripping up your floor to get to these,
either way as these lights are in the kitchen this is really a job for a part p electrician, it sounds to me that this was a very bad diy install in the first place and would strongly recomend you getting a qualified electrician to sort this issue out as i feel you are not compitant enough to fix this correctly, due to what you have asked so far..... you could end up making it potentialy more dangerous then before! plus he can test and certify his work and you will have peace of mind that you wont burn your house down and you will have all lights and switches working correctly.

 

[holmslaw]

..

 

[ban-all-sheds]

if you change to gu10 (230v) all the floating connector blocks you have mentioned will need to be enclosed in a choc box (should really be any way with 12v to prevent cable strain) and gu10 downlights should now really be earthed and most now come with an earth screw on top, if you replace the transformers you should really relocate them next to each light so they will be accessable from below without ripping up your floor to get to these,

" ... if ... will ... if ... "

It was a year ago - I expect he's done the job by now.

either way as these lights are in the kitchen this is really a job for a part p electrician,

Why?

would strongly recomend you getting a qualified electrician to sort this issue out

Too late for that now...