How to Wire a Ballast Bypass LED Tube (Type B Retrofit)

Switching from fluorescent tubes to LED in an existing fixture is one of the best lighting upgrades for a utility area or commercial space — better light quality, no flicker, no ballast to fail. But the wiring depends on which LED retrofit method you choose. Here’s how the ballast bypass works and when to use it.

Type A vs. Type B LED tubes

There are two main ways to retrofit fluorescent fixtures with LED tubes. Type A (“plug-and-play”) tubes work with the existing ballast — no rewiring needed. Type B (“ballast bypass” or “direct wire”) tubes bypass the ballast entirely and connect directly to 120V. Type B is the better long-term choice: ballasts are the most common failure point in fluorescent fixtures, and eliminating them removes that failure mode and reduces energy draw by 15–25%.

How to wire a Type B ballast bypass

Turn off the breaker and confirm power is off at the fixture. Open the fixture’s wiring compartment and locate the ballast. Identify the ballast’s input wires (connected to incoming 120V line and neutral) and output wires (connected to the tombstones/lamp holders). Disconnect and remove the ballast entirely. Cap the ballast’s output wires with wire nuts — they’re no longer needed. Connect the incoming line (black/hot) directly to the tombstones at one end of the fixture, and neutral (white) directly to the tombstones at the other end. The LED tube’s internal driver then receives 120V at its pins. Install the Type B LED tubes and restore power.

Important: Type B tubes are end-specific — single-ended or double-ended depending on the model. Single-ended tubes receive both hot and neutral at one end, with a dummy at the other. Double-ended receive hot at one end and neutral at the other. Read the tube’s label before wiring.

Ontario permit requirements

Modifying fixture wiring to bypass a ballast changes the fixture’s listed configuration. In Ontario, this work in a commercial space generally requires a licensed electrician, as it involves modifying fixed electrical equipment beyond simple lamp replacement. In a residential garage or utility room, ESA’s homeowner permit rules may apply. When in doubt, an ESA-licensed contractor can complete the bypass in 15 minutes per fixture.

Expert tip

We’ve completed hundreds of ballast bypasses in office and commercial spaces, and the most common mistake is installing Type B tubes in a fixture that wasn’t bypassed — or mixing Type A and B tubes in the same fixture. Type B tubes in an un-bypassed fixture will either not light or fail early because the ballast’s output voltage drives them incorrectly. Always label fixtures after bypass with a sticker (“LED bypass complete — Type B tubes only”) so the next person doesn’t install the wrong tube type years later.

Contact us

Planning a fluorescent-to-LED retrofit? Call us at 416-838-9006 or visit our contact page — we do ballast bypasses for commercial and residential spaces across the GTA.

Amir Azimipour

Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp