John Rumm wrote:
Andrew Gabriel wrote:

The rating info on the dimmer switch has two sets of figures with one
set, I assume, referring to the min and max wattage of the bulb stated
as 60-500W. The other set refers to 60-300W which I assume refers to
the rating of the dimmer control itself.


This is wrong, but I don't know what the second set is for.
It might the the max rating of halogen lamp.

The second set may be the derated capacity when used with an inductive
load (i.e. a halogen!)

Since when has a halogen lamp been an inductive load? Even if you
mean a transormer driven low voltage halogen it won't be very
inductive - nothing like a motor or solenoid.

--
Chris Green