There are many different types of fluorescent lights. These include the standard straight tube lights with a single pin. There are also U-shaped lights, with two pins on each of the legs of the U, and these U shapes can be very narrow and close together or more widely spaced.
While less common, there is also a Circline shape, which is a completely round fluorescent light. This is often used in retail lighting or in specialty lighting in commercial properties. These types of lights have two pins on each side of the base, which is actually in the circle where the two ends of the tube connect.
Bases and Sockets
Each fluorescent light shape has a specific type of base. The base determines the fluorescent light socket types that can be used with the light bulb. There are several different options from single and double pin styles, which can range from miniature to medium length.
There are also recessed double contact types of bases. The fluorescent light socket types are designed to only accommodate the specific type of base. However, there are some types of sockets that offer greater flexibility based on the specific ballast and configuration.
Shunted or Non-Shunted Sockets
The fluorescent light socket types, also known as lamp holders, can be designed to be shunted or non-shunted. These may be called tombstones due to the shape, and while they look the same, choosing the wrong option can create a fire hazard and always negatively impacts the life of the bulb.
The shunted types of lamp holders have the two sides joined, which allows a single way for electricity to move from the ballast to the lamp. With non-shunted, there are two different sides to the socket with two different electrical paths.
