Does anyone have any information or can explain what a GU-24 CFL is?

Compact fluorescents are either G24 or GX24 and then have a sub reference to describe the pin type. You can go to either the Osram or GE lamp catalogues to find detailed graphic information.

The GU-24 is a 120 volt pin/twist socket intended for high-efficacy light sources such as CFLs and LEDs. It is expected that the GU-24 will replace common Edison screw-_base_ sockets for those types of light sources.

The socket came out of a lighting industry "think tank" meeting held in December of 2003. There were a number of individuals involved, but the organizational participants included the American Lighting Association, NEMA and EPA/Energy Star. EPA/Energy Star confirmed the decision to use the GU-24 via a competition among several manufacturers and the EPA has been a strong supporter of the GU-24 socket development. The latest version of the Energy Star Program Requirements for Residential Light Fixtures V. 4.1 which goes into effect on 8/1/08 requires the use of GU-24 sockets, for example.

Some CFL manufacturers, such as TCP, already list integrally-ballasted CFLs with the GU-24 socket. SATCO, a socket/ballast manufacturer, lists several snap-in ballasts with GU-24 sockets for CFLs without integral ballasts.

The GU-24 design is in the process of ANSI standardization and it is also going through a U.L. review so as to limit its use to lighting with only fluorescent or LED light sources. This is so devices such as a GU-24 to Edison screw-_base_ adapter cannot be U.L. listed.

Terry McGowan

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