ANSI Type E – Type E metal halide lamps are enclosed-rated and only suitable for enclosed luminaires that have a glass lens or plastic lens rated for arc tube containment. These lamps have a standard mogul-base design with a broad contact point as shown. Typical for 175W to 1500W metal halide lamps.

ANSI Type S – Type S metal halide lamps are rated suitable for use in enclosed luminaires or in open luminaires if certain lamp manufacturer operating conditions are followed. These lamps have a standard mogul-base design with a broad contact point as shown. The Type S lamp rating currently is applied to metal halide lamps 350W or greater and will be available after January 1, 2005, for replacement of existing lamps.

ANSI Type O – Type O metal halide lamps are open-rated protected lamps for use in open or enclosed luminaires. These lamps have “EX” style exclusionary bases designed specifically for operation with protected pink sockets. The mogul bases of these lamps have a narrow contact point designed for protected lamp sockets. Type O lamps most commonly have a cylindrical quartz barrier around the arc tube, while some ceramic metal halide arc tubes are wrapped with wire. Typical for 175W to 1500W metal halide lamps.

Standard Mogul-Base Sockets – Standard sockets are constructed of porcelain and are white in color. The center contact tab will accept ANSI Type E, S, & O rated lamps. These sockets will continue to be used for metal halide HID lamps in indoor luminaires with enclosed optics.

 

Protected Mogul Base Sockets - Protected sockets are constructed of porcelain and are pink in color. The center contact tab is surrounded by a barrier that excludes ANSI Type E & S lamps by preventing contact between the center pin on the lamp base and center tab on the lamp socket. Type O rated lamps have a narrow center pin that fits in the barrier to make contact with the center tab. These sockets will be required for indoor HID metal halide luminaires with open optics to comply with 2005 NEC.