CLASSES OF INCANDESCENT LAMPS

Classes of incandescent lamps as cataloged by the manufacturers.

 

Large lamps, miniature lamps, and photographic lamps are the three major groups of incandescent lamps as divided and cataloged by the manufactures. As a summary, large lamps are those normally used for interior and exterior general and task lighting. Miniature lamps are generally used in automative, aircraft, and appliance applications. Photographic lamps, as the name implies, are used in photography and projection service.

Some of the main classes of large lamps are as follows:

 

General Service. These are for general lighting on 120-V circuits. Sizes range from 15 to 1500W with efficacies of 8 to nearly 23 lm/W. Lamps rated at 130 and other voltages are also available - consult catalogs or sales representatives of lamp manufacturers for specific listings.

 

High Voltage. High-voltage incandescent lamps are designed for operation directly on circuits of 220 to 300V. They are less rugged and have a lower efficacy than general-service lamps.There are also general-service incandescent lamps for 277-V circuits. One manufacturer cautions that such lamps be enclosed if used on high-capacity, lowe impedance electrical distribution systems.

 

Extended Service. These have a life of 2500 or more hours andare intended for use in applications where lamp failure causes an inconvenience, a nuisance, or a hazard to replace the lamp, or where replacement labor is expensive. They are less efficient than general-service.

 

General Lighting Tungsten-Halogen. These are compact, have better lumen maintenance, and provide a whiter light and a longer life.

 

Reflectorized. These are group of lamps embodying integral reflecting surfaces, bowl-silvered lamps are employed in direct-lighting equipment in which it is desired to shield the filament from view but principally in indirect equipment. Initial loss of light output due to the silvering is 6 to 10%; the rate of decline of light output is considerably greater than in clear-bulb lamps of corresponding sizes.

 

Small Tungsten-Halogen Lamps. Families 1 3/8 - and 2-in-diameter,12-V models having internal multifaceted reflectors, providing a range of beam spreads for accent and display lighting. Dichroic reflector coatings reduce approximately two-thirds of the heat in the beam by emitting infrared energy to the rear, thus deceasing fading of color-perishable items that are illuminated.

 

Rough and Vibration Service. These lamps are for use where lamps are subjected to shock and vibration while in use. Filament construction differs. Rough-service lamps are available from 25 to 200W, whle those for vibration service range from 40 to 150W.

 

Street Lighting. These lamps are availalbe for series burning and multiple burning. The former are rated according to lumen output and the latter according to watts. Ingeneral the lumen maintenanceof series lamps is better than that of multiple lamps. The latter are rated on a basis such that their average lumens throughout lifeare approxiamtely equivalent to those of series lamps of corresponding sizes.

 

Decorative Lamps. Incandescent lamps in many bulb shapes, bases, and wattages are available for a variety of decorative and architectural lighint applications.Some have specific requirements regarding burning position, shielding from moisture, etc., as covered in technical literature of the fluorescent lamps.