Replacing fluorescents with LED tubes — Type A, B, and C, explained
Applies to: All fluorescent fixtures considering LED conversion
What this error means
The industry's UL taxonomy, worth knowing before any quote: Type A tubes are plug-and-play — they run on the existing ballast, lowest labor, but the ballast remains a future failure point and compatibility must be checked per tube. Type B is ballast bypass — the ballast is removed and the sockets wired to line voltage; it eliminates ballast failures forever but requires qualified rewiring and a mandatory 'modified fixture' relabel to preserve the UL listing (fixture can never take fluorescent tubes again). Type C uses an external LED driver — best efficiency and dimming, highest cost. For most offices: Type B across a floor kills the ballast-replacement treadmill permanently.
Symptoms
- Recurring ballast failures
- Tubes dimming/flickering fleet-wide
- An electrician quoting 'ballast replacement' — the moment to ask about retrofit instead
Try this first (safe DIY steps)
- Count your fixtures and note tube type (T8/T12) — T12 magnetic gear is phased out anyway; the decision is when, not if
- Type A: genuinely DIY if the tube lists your ballast as compatible — but you keep the ballast lottery
- Type B and C: qualified installer; insist on the UL relabel on every modified fixture
- Get the retrofit quoted per-fixture against a $150 ballast replacement — the math usually ends the meeting
Safety: power off before any physical intervention. Never bypass covers or interlocks — fuser areas run hot enough to burn.
When to call a technician
Type B/C conversion is electrician work by design (line voltage at the sockets). LED tubes run ~$5–15 each; documented rewiring labor is minutes per fixture at scale.