Upgrade T8 or T12 fluorescent fixtures to Feit Electric LED tubes in under 30 minutes — no electrician required. This guide covers Type B ballast-bypass and Type AB hybrid wiring, with a step-by-step diagram and full compatibility table.
In This Guide
What is a Type B or Type AB Hybrid LED Tube?
Type B (Ballast-Bypass) tubes replace most T8 and T12 fluorescent tubes by wiring directly to line voltage, skipping the ballast entirely — more energy-efficient and one less component that can fail. Type AB Hybrid tubes go a step further: they work both with a compatible ballast (like Type A, no rewiring) and with direct line voltage after ballast bypass (like Type B). This makes Type AB the most flexible option if you're retrofitting fixtures in stages or across a mixed inventory.
Type A (plug-and-play) tubes keep the ballast in place — easiest to install, but you're still powering the ballast. Type B and Type AB bypass the ballast and pay off long-term in energy savings and reduced maintenance. Not sure which type fits your fixture? See our LED linear tube buying guide →
What You'll Need
or Nut Driver
Connectors
Stripper
Glasses
Safety First
Always verify power is off at the breaker before touching any wires. Confirm with a multimeter — never assume. Wear safety glasses throughout. Ballast-bypass work involves line voltage (120V AC) and must be treated as live until confirmed dead.
Step-by-Step Instructions
Turn Off Power
Kill the breaker that supplies the fixture — not just the wall switch. Wall switches interrupt the hot leg but the neutral remains live; the breaker cuts both.
Remove your old fluorescent tubes. Then use your multimeter: touch one probe to each socket contact. It should read 0V. If it reads anything else, find the correct breaker and try again.
Cut Ballast Wires
Remove the ballast cover (usually 2–4 screws). You'll see the ballast with wires going in from the fixture's power feed and out to the lamp sockets.
Cut all wires connected to the ballast — the incoming hot and neutral, and all wires leading to the sockets. Cut close to the ballast body to leave maximum wire length to work with. Optionally remove the ballast with your nut driver.
Connect Hot & Neutral Wires
Strip approximately 1 inch of insulation from all four wire ends: both socket wires and both feed wires (hot and neutral).
Using wire connectors, join one socket side to the neutral wire. Then join the opposite socket side to the hot wire. Each connector should hold two wires. Tug each connection to confirm it's secure.
Polarity matters
Each socket side must connect to only one wire — hot on one side, neutral on the other. Mixing them will prevent the tube from lighting.
Cover Wires & Label
Group all wire connectors neatly and fold them into the fixture. Replace the ballast cover plate and secure the screws.
Affix the fixture retrofit label on the outside of the cover plate where it's clearly visible. This tells anyone replacing a tube in the future that the ballast has been bypassed — critical for safety and correct tube selection.
Insert Type B or Type AB Hybrid Tubes
Check the end caps on your Feit Electric tube before inserting. Type B tubes are marked N (Neutral) on one end and L (Live) on the other — match each end to its corresponding socket. Type AB Hybrid tubes use a double-ended configuration, meaning both ends receive power; insert with either end in either socket.
Insert by aligning the pins, then rotate the tube a quarter-turn until it clicks into place — same motion as the fluorescent tubes you removed.
Not sure which tube fits?
To find the right Type B or Type AB tube for your fixture length and socket type, Read more linear tube guide →
Restore Power & Test
Replace the glass or diffuser cover. Restore the breaker and flip the wall switch.
Your Type B LED tube should light up immediately — no warm-up time, no flicker. If it doesn't, see the troubleshooting section below.
Installation complete
You've bypassed the ballast. Future tube replacements just require a Type B or Type AB hybrid LED — no rewiring needed. The retrofit label you applied in Step 4 will remind you.
Wiring Diagram
How hot and neutral connect from the fixture feed to each socket after ballast bypass. Type B (single-ended): hot to one socket side, neutral to the other — tube end caps marked N and L. Type AB Hybrid (double-ended): both socket sides receive hot + neutral joined; either tube end fits either socket.
T8 vs T12 Compatibility
Confirm your fixture type before purchasing. Check the tube currently installed — the type is printed on the tube itself. 🔗 Click here to see the latest Feit Electric Linear Bulb Ballast Compatibility
| Tube Type | Diameter | Common Lengths | Bypass Compatible? | Recommended |
|---|---|---|---|---|
| T8 | 1 inch | 2ft, 3ft, 4ft, 8ft | ✓ Yes | Type B or Type AB |
| T12 | 1.5 inches | 4ft, 8ft | ✓ Yes | Type B or Type AB |
| T5 | 5/8 inch | 2ft, 4ft | Varies | Type A |
| T8 (working ballast) | 1 inch | Any | Optional | Type AB — works now without bypass, bypassed later |
Troubleshooting
Tube installed but something's off? Run through these checks before calling it in.
| Symptom | Likely Cause | Fix |
|---|---|---|
| Tube won't light at all | N/L ends swapped, or breaker not fully on | Rotate tube 180°. Confirm breaker is fully tripped ON. |
| One end dark, one end lit | Pins not fully seated in socket | Remove tube, re-insert with firm pressure, rotate until it clicks. |
| Flickering | Loose wire connection at connector | Power off. Re-open connector, ensure both wires are fully inserted, re-tighten. |
| Buzzing sound | Ballast still in circuit (wiring error) | Power off. Verify both socket sides are wired to hot and neutral directly — not looped through the old ballast location. |
Frequently Asked Questions
Do I need an electrician to bypass a ballast?
No. Ballast bypass is a DIY-safe task as long as power is confirmed off at the breaker before any wiring. Always verify with a multimeter. If your fixture has unusual wiring or is part of an emergency lighting circuit, consult a licensed electrician.
Does ballast bypass work for both T8 and T12 tubes?
Yes. Feit Type B LED tubes are compatible with most T8 and T12 fixtures after ballast bypass. Verify the tube's spec sheet for your exact fixture length and socket type before purchasing.
How long does it take to bypass a ballast?
Most single-fixture bypasses take 20-30 minutes. If you're retrofitting multiple fixtures in a row, each additional fixture takes about 10-15 minutes once you've done the first.
What happens if I connect hot and neutral to the wrong sockets?
The tube won't light. No permanent damage occurs from a single incorrect connection. Check the N and L markings on the tube's end caps and rewire the connector on the incorrect side.
Can I use a Type A plug-and-play tube instead of bypassing?
Yes, if your ballast is compatible. Type A tubes require no rewiring. However, you're still powering the ballast, which draws extra wattage and will eventually fail. For the best of both worlds, consider Type AB Hybrid - it works plug-and-play with a compatible ballast today, and can be switched to ballast-bypass mode later with no new tube purchase.
What is a Type AB Hybrid tube and how is it different from Type B?
A Type AB Hybrid tube is compatible with both ballast-driven (Type A) and ballast-bypass (Type B) installations. Type B tubes only work after the ballast has been removed and the fixture rewired. Type AB gives you flexibility - especially useful when retrofitting a large facility in phases, or when you have a mix of old and new ballasts.
Need Help Choosing the Right Tube?
Not sure whether Type A, Type B, or AB Hybrid is right for your fixture? Check ballast compatibility before you buy.
Check Ballast Compatibility →
