Posted by Doug Root on 9th Jul 2019

The Differences Between Double Ended and Single Ended LED Tubes and the New Player - Combo LED Tubes!

Are you looking to replace your fluorescent lamps and ballasts with direct wire LED T8 tube lights? Have questions about the differences between ballast bypass single-ended tubes, double-ended tubes, and now the ultra-versatile single/double combo LED tube? If so, read on and get more information on installation with our wiring diagram for LED tube lights.

Single-Ended LED Tube

The single-ended LED T8 tube is also known as the "ballast bypass" lamp. Single-end power LED tubes eliminate the need for an external driver or ballast. They have line and neutral pins on one single side of the lamp. For new construction installations, you simply connect the 120 or 277 line voltage directly to the one live end (input end) lamp holder. The other end is basically a non-electrified lamp holder because no electricity is being fed to that end. For retrofit installations, bypass the existing ballast by cutting the wires and connecting the 120 or 277 line voltage directly to the input lamp holder on the single end.

Single-ended LED T8 lamps will only operate on non-shunted sockets. Typically, these sockets are in T8 fluorescent instant start fixtures but are not in older F40T12 fluorescent troffers. Verify non-shunted sockets are installed before using a single-ended LED tube. Below are a few pictures of the various socket configurations you may find in our wiring diagram for LED tube lights.


Double-Ended LED Tube

Double-ended Tubes

A double-ended LED T8 tube has line and neutral pins on each end of the lamp. Since fluorescent linear lamps are typically double-ended, the installation of double-ended lamps can be easier.

Typically, double-ended lamps use shunted lamp holders, although some of the new combo units use shunted or non-shunted sockets. Shunted sockets are used in these applications because you want the two contact pins on the live end to be shorted together, so they are both receiving line voltage. When installing both the double-ended and single-ended LED tube lamps, be sure to check our wiring diagram for LED tube lights.

DirectDrive DX2 - Double & Single Ended Operation

The new DirectDrive DX2 from Keystone Lighting Technologies allows you to choose which way you would like to wire the fixture. The lamp can be driven by wiring voltage directly to one single end and using non-shunted sockets, or you can wire the lamp for double-ended operation. Many school systems and contractors choose the DX2 because, for fluorescent T8 lamps, the single-end wiring option is best, but for the older T12 systems, the double-ended shunted installation is more convenient. When you have this lamp, you can solve any situation you may run into.

Keystone DirectDrive LED T8 DX2

Double-Ended LED T8 Wiring - Direct Drive DX2

Do you still have questions about our wiring diagram for LED tube lights? Give us a call at 1-888-988-2852. We are standing by and ready to help you with your next lighting project.