Satco 03720 40W A15 Clear 120V Standard Bulb

40W A15 Incandescent Bulb for 120V Fixtures

This Satco A15 incandescent lamp operates at 40 watts on a 120 volt supply with a medium screw E26 base. The clear glass envelope produces 290 lumens of warm light. It suits table lamps, ceiling fixtures and appliance sockets that accept the A15 shape. Rated life is 2500 hours under normal cycling.

Practical Limits of Incandescent Technology

Incandescent bulbs convert most input power into heat rather than visible light, so surface temperatures become high during operation. Fixtures must be rated for at least 40 watts and provide adequate ventilation. The 120 volt rating means the lamp is not suitable for 130 volt supplies without reduced output and shortened life. Frequent switching further reduces the 2500 hour average lifespan.

40 Watt Power Draw Decides Suitability

The 40 watt consumption determines whether the bulb fits the fixture’s maximum wattage label and the circuit’s load budget. Buyers who need higher lumen output or lower energy use cannot meet those needs with this lamp. The fixed 290 lumen output and 2500 hour rating are direct consequences of the 40 watt incandescent design.