Philips Lighting 369785 F48T12/CW/HO ALTO 15PK

The F48T12/CW/HO ALTO takes an R17d recessed double contact base, not the bi-pin base found on standard 48 inch T12 lamps. A recessed double contact socket is the giveaway on high output fixtures. If your sockets are medium bi-pin, this lamp will not seat and you need a standard output F40T12 instead.

Cool white here means color code 33 at 4100 K, the traditional cool white shade used across older T12 installations. If the existing lamps in the building are 4100 K cool white, this drops in and matches. If they are 3500 K spec35 or 5000 K daylight, you will see the difference across a bay, so relamp a whole fixture row at a time rather than mixing.

The 369785 F48T12/CW/HO ALTO ships as a 15 pack of 48 inch lamps. That case quantity is how it is sold, which suits a facility relamping a bay or stocking an MRO shelf rather than a single-lamp swap.

ALTO lamp technology means low mercury, and the mercury content is 3.5 mg nominal, which is why the lamp is TCLP compliant and carries the green end cap that identifies ALTO product on the shelf. Low mercury does not mean no mercury. The lamp still contains mercury and has to be managed under applicable disposal laws, so route spent lamps to a recycler rather than general waste.

Color rendering index is 62, which is normal for cool white halophosphate lamps and fine for warehouse aisles, distribution floors and factory bays where you need footcandles, not color fidelity. For paint matching, print inspection or retail display, 62 CRI is too low; look to a higher CRI lamp such as an ultralume color in the same family.

The F48T12 HO ALTO family runs 35, 40, 50, 55, 60, 75, 80, 85 and 100 watts, so the 60 watt cool white lamp is one point on that range. Same 48 inch length and same recessed double contact base across the line, so you can step wattage within the family without changing fixtures, as long as your ballast is rated for the wattage you pick.

Output is published at 800 mA operation for this lamp. Philips lists 1000 mA operation as a separate condition with different approximate lumens, so if your fixtures use very high output ballasts, do not plan a layout off the 4050 lumen figure. For an 800 mA HO ballast, 4050 initial and 3500 mean are the numbers to design to.