SYLVANIA 49947 - QTP4X32T8/UNV ISN-SC

This T8 Instant Start Fluorescent Ballast is designed for 3 or 4 lamp configurations. While not an LED driver, it is compatible with ballast-compatible LED tubes—see our upgrades section for more details.

Featuring a standard mechanical form factor, this ballast fits seamlessly into most T8 commercial luminaires, including 2x4s, 1x4s, strips, and surface mounts. With a Normal Ballast Factor, it operates fluorescent or LED lamps at 80 to 90 percent of their rated capacity, which may vary based on the number of lamps in the circuit. For example, using three 4-foot T8 lamps increases the ballast factor, while using four 4-foot T8 lamps returns it to normal. Using 2 or 3-foot lamps will elevate the ballast factor again.

Generally, these output variations are not noticeable to occupants, as this ballast is most commonly used in a four-lamp, four-foot fixture. It operates universally between 120 and 277 volts, providing versatility for various applications.

Additionally, the ballast can be removed from the fixture, allowing for the installation of ballast-bypass tubes with minimal electrical work. For more information on this upgrade option, please refer to our upgrades section.