LED T8 Retrofit Tube Buying Guide: Type A/B/C Ballast Options, Lamping Efficiency, and the Wiring Check That Prevents Fires

Type A, B, or C: The Decision That Precedes Everything

Every LED T8 retrofit fits into one of three UL classifications, and the letter decides how it's installed and how it fails. Type A is plug-and-play: it runs off the existing fluorescent ballast. Type B is ballast bypass: line voltage wired straight to the socket, no ballast at all. Type C is a tube with an external driver that replaces the ballast.

Type A vs B vs C at a Glance

Type	Ballast	Install	Maintenance	Best For
Type A	Uses existing	Seconds, no wiring	Ballast remains a failure point	Quick retrofit, leased space
Type B	Bypassed	Rewire required	Zero ballast after	Large relamps, long hold
Type C	External driver	Driver swap	Driver is the wear item	Dimming, high ceilings

For most large relamps, Type B wins on lifetime maintenance. You rewire once, and there's no ballast left to hum, flicker, or die. For a quick retrofit where the ballasts are still good and you don't want to touch the wiring, Type A. Type C earns its keep when you need dimming or the fixtures are hard to reach.

Ballast Bypass and the Wiring You Can't Skip

If you go Type B, the wiring choice is a safety decision, not a preference. Single-ended feeds power to one end only; the pins on the other end are dead. Double-ended feeds both ends, matching the old fluorescent wiring, but it leaves one end live while the tube is partly inserted.

Single-ended is the safer standard, and it's what we recommend for self-install projects. The cost of getting it wrong isn't a flicker, it's an arc and a trip to the emergency room. Whatever you choose, every fixture must be relabeled to warn the next person against reinstalling a fluorescent tube. A retrofit that isn't relabeled is an accident waiting for the next maintenance visit.

Lumens Per Watt Is the Real Price Tag

A 32W T8 fluorescent delivers roughly 2,600 to 2,900 lumens through a standard ballast. A good LED replacement matches that at 15 to 18 watts. That's the whole value proposition: cut power in half, hold light output. So shop by lumens per watt, not by the wattage number.

Anything under 140 lm/W is last-generation inventory someone's trying to clear. The current field runs 150 to 190 lm/W. Check the ballast factor too. A low-factor ballast can shave 10 to 15% off a Type A tube's output, which is how a buyer ends up with a dimmer space and no idea why.

Glass vs Plastic, and Why the Listing Matters

Plastic, almost always. A polycarbonate tube won't shatter and spray glass and mercury residue the way a fluorescent can, and it survives being dropped on the job site. Glass is cheaper and sometimes preferred for optics in cold environments, but the shatter risk isn't worth the few cents saved on a bulk relamp.

Then check the listing. A DLC or equivalent listing plus a UL 1598C classification for retrofit use matters twice: it's a baseline quality signal, and utilities often require it for rebate programs. Miss the listing and you leave rebate money on the table, or worse, buy a tube that doesn't actually pass.

Common Questions from Buyers

Type A, B, or C — which LED tube should I buy?

Depends on the fixture and who maintains it. Type A is plug-and-play and works with the existing ballast, so it installs in seconds but inherits the ballast as a future failure point. Type B bypasses the ballast and wires line voltage straight to the socket, which means rewiring but zero ballast maintenance after. Type C uses an external driver and is the efficiency and dimming leader, at a higher installed cost. For most large relamps, Type B wins on lifetime maintenance. For a quick retrofit with old ballasts you don't want to touch, Type A.

Single-ended or double-ended wiring for ballast bypass?

This is the safety question. Single-ended feeds power to one end only, with the pins on the other end dead, so there's no risk of touching a live pin during installation. Double-ended feeds both ends, which matches the old fluorescent wiring but leaves one end live when the tube is partly inserted. Single-ended is the safer standard and what we recommend for self-install projects. Whatever you choose, the fixture must be relabeled to warn against reinstalling a fluorescent tube.

How many lumens to replace my T8 fluorescent?

A 32W T8 fluorescent delivers roughly 2,600 to 2,900 lumens through a standard ballast. A good LED replacement matches that at 15 to 18 watts, which is the point: you're cutting power by half while holding light output. Look at lumens per watt, not the wattage number. Anything under 140 lm/W is last-generation; the current field runs 150 to 190 lm/W. Check the ballast factor too, because a low-factor ballast can shave 10 to 15% off a Type A tube's output.

Glass or plastic tube?

Plastic, almost always. A polycarbonate tube won't shatter and spray glass and mercury residue the way a fluorescent can, and it survives drops on the job site. Glass is cheaper and sometimes preferred for optics in cold environments, but the shatter risk isn't worth the few cents saved on a bulk relamp. Also confirm the tube carries a DLC or equivalent listing and a UL 1598C classification for retrofit use, since utilities often require it for rebate programs.

Source T8 retrofit tubes with verified listings and lumens-per-watt specs from Compare2Best.

This article is produced by the Compare2Best knowledge team and reviewed by commercial lighting specialists. Updated August 2026. Ballast compatibility, wiring, and listing requirements vary by fixture and utility program; confirm with a licensed electrician and the supplier before ordering.