SATCO Lighting S39901 9W T8 LED, 2Ft, 3500K, Medium Bi Pin Base, 50000 Avg Rated Hours, 1100 Lumens, Type B, Ballast Bypass

Yes. The S39901 is a Type B ballast bypass lamp, which means it runs on line voltage directly to the sockets. The existing fluorescent ballast has to be disconnected and removed, and the sockets wired to line voltage. Drop it into a fixture with a working ballast still in the circuit and you will damage the lamp. If you want a tube that works with the ballast left in place, you need a Type A (plug-and-play) lamp instead, not this one.

Either. The S39901 accepts single or double ended wiring, so it works whether the electrician brings line and neutral to one end of the fixture or splits them to opposite ends. That matters on a retrofit where the existing tombstones are non-shunted at one end and shunted at the other, because you are not forced to swap sockets to match a single wiring scheme.

3500K is a neutral white, between the warmer 3000K and the cooler 4000K. If the rest of the building is lamped at 4000K the S39901 will read visibly warmer side by side, so for a fleet of fixtures pick one color temperature and stay with it. Where the existing lamps are 3500K fluorescent, this matches. In practice, lamp a whole room or corridor at a time rather than spot-replacing, since a mixed run is where the difference shows.

1100 lumens from 9 watts. A 2-foot F17T8 fluorescent draws 17 watts, so you are cutting connected load by roughly half per lamp while staying in the same light output range, and the LED holds its output without the lumen depreciation a fluorescent shows over life.

50,000 average rated hours. On a 12-hour-a-day schedule that is over 11 years of service, and on a 24/7 corridor or stairwell it is close to 5-3/4 years. For an MRO or property maintenance program that is the number that justifies the retrofit: the labor of the ladder trip usually costs more than the lamp.

No, and this is the part that catches property managers out. Converting a fixture to Type B means opening the fixture, cutting out the ballast, and rewiring the sockets to line voltage, which is electrical work on a branch circuit. That is a job for a licensed electrician, not a general maintenance swap. Once the fixture is converted, the lamp itself changes out like any tube.

Ballast bypass makes sense when the fixture housing, lens, and sockets are in good shape and you want the ballast out of the failure path for good, because after conversion there is nothing left in the circuit but the lamp. The trade-off is one-time electrician labor per fixture. If the housings are corroded, the lens is yellowed, or you are changing the light distribution, a new LED fixture is the better spend. For a large fleet, the bypass route is usually chosen because it standardizes every fixture on one replaceable lamp, the S39901 in this case, with no ballast inventory to carry.

S39901 is the Satco Lighting number for the 9W 2-foot T8 LED in 3500K with a medium bi-pin base, Type B ballast bypass. Satco numbers a separate SKU for each color temperature in this family, so quote S39901 specifically when you need 3500K rather than a generic 9W 2ft description.