4 Blown Dimmers ?!?!?

[jslinnha]

Hi All,

I have had my lighting replaced in the kitchen with 240v Halogen spots

I have 2 banks of 6 lights, fed by a 2g dimmer.

Each of the banks totals 300W, my electrician (and various Manufacturer sites) states that we need to uprate by 20% - so a 400W dimmer shouold be fine.

However, we are about to replace one of the dimmer modules for the 4th time.....

Any suggestions as to why the dimmer modules would keep blowing ?

Thanks in advance

Jon

 

[Spark123]

The surge caused by a failing lamp can take out the semiconducor in the dimmer.
Halogens also have a high inrush current when they are first switched on. As a rule of thumb when using halogens you should double the size of dimmer switch to the halogen load unless the switch manufacturer says otherwise.

 

[RF Lighting]

You could try better quality dimmers.

Soft start ones prolong lamp life, and often do not require derating when used with halogen loads.

 

[sparkybird]

If you use branded lamps (eg Osram, GE etc) these have an internal fuse in each lamp which will protect the dimmer if the lamp goes.

SB

Oh, and I understood that the dimmer max load should be 1.5x the actual load, so each dimmer at 450W. You might struggle to find this on a single plate...

 

[Taylortwocities]

This might help http://www.tlc-direct.co.uk/Technical/DataSheets/Systems/DimmerGuide.htm

 

[securespark]

If you use branded lamps (eg Osram, GE etc)

Wahey!!

Some of my Osram Obsession has rubbed off on you SB!!!

You beat me to it!

To the OP, MK even put warnings in their dimmer packaging about using branded lamps, otherwise it will get toasted in the event of lamp failure.

Use quality gear always.

 

[johnnykc]

You could try better quality dimmers.

Soft start ones prolong lamp life, and often do not require derating when used with halogen loads.

The problem is unlikely to relate to the dimmers....sparkybird had it right with the branded lamp suggestion... by the way, cheap imported GU10s (non fused) can easily fry a dimmer regardless of de-rating.

 

[sparkybird]

Yes, contrary to popular belief (hubby!), I do listen and take things on board, although obviously I'm always right!!

SB

 

[ban-all-sheds]

I use branded lamps.

9 times out of 10 when one fails it takes out the MCB.