240V and 3-Wire LED Wiring Diagrams | Photocell & Ballast Bypass Explained

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If you want to switch to LED Lights with 240 volt, you might encounter a wiring challenge. You might have two hot wires and a neutral/ground coming out of the building. In the USA, 120 volt and 277 volt use three classic wires: a hot, a neutral, and a ground. This is the electricity we have all been taught about. 240 volt AC (V=volt, AC=alternating current) throws a spin at you.

It uses two hot wires at 120 volt each that alternate positive to generate the full 240 volt and a ground for safety - no neutral is needed, because the two hots complete the circuit between themselves (as if this isn't confusing enough). By combining the two 120 volt wires, you get 240 volt AC. We'll spare you the technical details of 240 volt and its advantages and disadvantages, but Wikipedia does a good job explaining it. We are going to focus on getting the job done and getting the LED light bulbs, parking lot lights or other installed.

Black, black and green (or other random color)? Yes, in a split phase setup you commonly have black=hot, red=hot and green=ground. Sometimes you see two hot wires both as black. So that is black=hot, black=hot and green (or whatever they want)=ground, but that is less common. There is a ballast, how do I wire my 240 volt to the socket or LED driver? Yes, most of the time when retrofitting to LED Light Bulbs you will have to bypass the ballast and wire direct to the light socket.

That is because higher lumen output bulbs like metal halide, HID or CFL all require a ballast to work correctly. LEDs use a driver and not a ballast. If you are replacing an incandescent then you will not need to. The good news is that rewiring is easy to do. You are literally cutting the ballast out of the system and throwing it away. Then taking those wires and direct connecting to the socket or driver. This cuts out a future point of failure in the ballast as well.

How do I wire the 240 volt 3 wire light socket? Whether it is a classic E26 or larger mogul E39 light bulb we recommend the same thing. Treat the red wire as the hot and land the black on the socket's neutral position. The socket then sees the full 240 volts across its contacts, which is fine for LED bulbs and drivers rated 100-277 volt - the driver does not care that neither leg is a true neutral. Confirm that voltage range on the bulb or driver label before wiring. Doesn't it work better on 240 volt or 277 volt?

Unlike metal halides that worked better with more juice, and even required a pulse start setup for optimal performance, LEDs just do not need it. In fact, the LED driver inside an LED Corn Bulb converts the power from AC to DC for each of the LEDs. What if there is a separate driver? Or just brown, blue and yellow stripe wires? If you are not retrofitting a light bulb socket, but a whole LED high bay light or LED retrofit kit with driver, you do the same thing.

Connect red to brown and black to blue. If they are using American wiring instead of international, then it's red to black and black to white. Here is an illustration of how to wire 240 volt AC split phase for ballast bypass: