DIY Doctor UK DIY Forums

can anyone help? with downlighters what does GU10 or GU17 mean with regards to the lamp? thanks for any replies :D

Never heard of GU17.
GU10 and GZ10 are spot light bases for 230 volt lamps.
GZ10 are Dichroic have a special multi-layer coating on the reflector of the lamp this means that visible light is reflected forwards whilst the heat is transmitted backwards through the rear of the lamp.
The GU10 base has a slight taper as it reaches edge of holder where GZ10 below has square shoulder so non-dichroic GU10's will fit either holder but a GZ10 dichroic will only fit in a GZ10 holder so only fitting able to deal with the heat coming through the back of the light can be used.

[quote="ericmark"]Never heard of GU17.
GU10 and GZ10 are spot light bases for 230 volt lamps.
GZ10 are Dichroic have a special multi-layer coating on the reflector of the lamp this means that visible light is reflected forwards whilst the heat is transmitted backwards through the rear of the lamp.
The GU10 base has a slight taper as it reaches edge of holder where GZ10 below has square shoulder so non-dichroic GU10's will fit either holder but a GZ10 dichroic will only fit in a GZ10 holder so only fitting able to deal with the heat coming through the back of the light can be used.[/quote]

thanks for your reply