Following on from a recent thread (but not wanting to divert his
discussion away hence this new one) regarding the commonly known
de-rating of dimmers for use with halogen lamps can anyone tell me why
it is also neccessary to de-rate dimmer capacity for candle lamps
against GLS/reflectors?

I can understand that the inrush currents for halogens when cold are
far higher than that for GLS lamps, hence the de-rating, however what
are the technical differences between a candle lamp and a
similarly-rated GLS/reflector lamp? I had, clearly errouneously,
assumed that the 'innards' were the same and that it was merely the
shape of the bulb that was different?

Can anyone err... enlighten me? ;-)

Mathew

Mathew Newton wrote:
Following on from a recent thread (but not wanting to divert his
discussion away hence this new one) regarding the commonly known
de-rating of dimmers for use with halogen lamps can anyone tell me why
it is also neccessary to de-rate dimmer capacity for candle lamps
against GLS/reflectors?


As I understand it, candle bulbs are unusually prone to failing near
short circuit.
So, you want a higher rated dimmer to cope with the spike when they fail.

On 26 Aug 2005 15:06:04 GMT, Ian Stirling
wrote:

As I understand it, candle bulbs are unusually prone to failing near
short circuit.
So, you want a higher rated dimmer to cope with the spike when they fail.

300W of candles will reliably kill one of B&Q's 400W dimmers after a
bulb failure. 8-( (I have the pile of failed dimmers)

Andy Dingley wrote:
On 26 Aug 2005 15:06:04 GMT, Ian Stirling
wrote:

As I understand it, candle bulbs are unusually prone to failing near
short circuit.
So, you want a higher rated dimmer to cope with the spike when they fail.

300W of candles will reliably kill one of B&Q's 400W dimmers after a
bulb failure. 8-( (I have the pile of failed dimmers)

Thank you both for the responses - I had no context for the question
other than general interest so they should suffice!

Mathew