The key difference between shunted and non-shunted tombstones lies in how electrical current flows through them. Shunted sockets allow current to travel through multiple paths, while non-shunted sockets direct the current through a single path. Using the wrong type of socket with an incompatible ballast or bulb can lead to lamp failure, ballast damage, and may void component warranties.
The correct fluorescent socket depends on the ballast type used in your fixture. Fixtures with rapid start, programmed start, or dimming ballasts require non-shunted lamp holders, whereas fixtures with instant start ballasts use shunted lamp holders.
If you’re retrofitting fluorescent fixtures with LED tube lights, check whether the sockets need replacement. Typically, plug-and-play LED tubes can use existing sockets, while direct-wire (ballast-bypass) LED tubes require non-shunted lamp holders and bypassing the ballast entirely. Always verify the lamp’s specification sheet before purchasing. If there’s a conflict between ballast and lamp requirements, follow the lamp manufacturer’s specifications.
