Why Ballasts Matter in Your Lighting System

Updated: August 28, 2025

~7 min read • ~1,499 words • Flesch ~60

TL;DR: The right ballast or LED driver protects lamps, stabilizes current, and keeps jobs passing inspection. Match lamp type and wattage, verify supply voltage, select the correct output (ballast factor or driver current), confirm environment ratings, and follow NEC 2023 for listing and disconnects. Standardize SKUs and label retrofits. When projects touch emergency lighting, large controls networks, or unusual environments on Long Island, call the AHJ before you order or rewire.

Why it matters

Ballasts and LED drivers keep lamps stable and efficient. The right unit protects components, reduces callbacks, and helps you pass inspection. On Long Island, many projects mix legacy fluorescent or HID with new LED. Matching the ballast or driver to the lamp prevents flicker, color shift, early failures, and nuisance tripping. Start planning with the ballasts and drivers category for stocked options and specs.

Fundamentals

Ballast vs driver. Fluorescent and HID lamps need a ballast to limit current and provide proper starting. LED luminaires and retrofit lamps use a driver that regulates constant current or constant voltage.

Key specs. For fluorescent, ballast factor changes light output relative to lamp rating. Power factor and THD affect efficiency and breaker loading. For LED, match the driver’s output type and range, such as 350–1050 mA constant current. Check case temperature and ambient limits on the label.

Compatibility. Fluorescent ballasts are tied to lamp type and wattage, such as F32T8 or F54T5HO. HID ballasts follow ANSI codes like M98 for 150 W ceramic metal halide. LED drivers must match the LED board’s voltage window at the chosen current. When in doubt, use a listed retrofit kit.

Browse stocked LED drivers and metal halide ballasts for fast replacements.

Code & compliance (NEC 2023)

Follow listings and instructions per 110.3(B). Luminaires and retrofit kits must be listed per 410.6. Where fluorescent or LED luminaires with double-ended lamps have a serviceable ballast or driver, provide a disconnect per 410.71. Check environmental ratings under 410.10 for damp or wet locations. For conversions, use a listed kit compliant with UL 1598C and apply permanent labels. Energy and efficiency guidance is available from the U.S. Department of Energy’s ballast procedures. Local adoption varies across Long Island jurisdictions. Confirm with the authority having jurisdiction before ordering or rewiring.

Selection steps

1. Confirm lamp family and model. Example: F32T8 fluorescent, 150 W HPS, or an LED board 36–42 V at 700 mA.
2. Match supply voltage. Choose 120 V, 277 V, 347 V, or universal input.
3. Pick output level. Ballast factor 0.77, 0.88, or 1.18 changes lumens. For LED, select the current set point that meets thermal limits.
4. Choose controls. 0–10 V dimming is common. Verify control class and wiring segregation.
5. Check environment and fit. Case temperature, damp or wet rating, vibration, and footprint.
6. Standardize for maintenance. Stock common SKUs and record model numbers in O&M docs.

Need help choosing? Bring the failed unit to the counter or email photos of the label and wiring for a quick match. Start with the ballasts and drivers category for stocked options.

Sizing and configuration examples

Fluorescent: four F32T8 on an electronic ballast

Given: 4× F32T8 lamps rated 2900 lm each. Ballast factor BF = 0.88.

Lumens: 4 × 2900 lm × 0.88 = 10,208 lm. Round to 10,200 lm for planning.

Input power check: If ballast input is 0.44 A at 120 V per two lamps, P ≈ 120 V × 0.44 A = 52.8 W. Two channels give ≈ 105.6 W. Round to 106 W. Verify on the data sheet.

LED driver: constant current board at 700 mA

Given: LED board forward voltage Vf = 36 V at 700 mA.

Driver power: Pout = I × V = 0.700 A × 36 V = 25.2 W. Select ≥ 26 W with headroom. If trimming current by 10%, I = 0.63 A, Pout ≈ 22.7 W.

For stocked options that fit these cases, see LED drivers or ask the counter for a cross.

Installation & wiring notes

• De-energize and verify absence of voltage. Lock out the circuit as required by your safety program.
• Follow the listing and the manufacturer’s instructions per NEC 110.3(B). Keep the wiring diagram with the O&M records.
• For fluorescent or LED luminaires with double-ended lamps and a serviceable ballast/driver, include a disconnect per NEC 410.71. Locate it where it is accessible with the lens removed.
• Use listed retrofit kits per NEC 410.6 when converting from fluorescent or HID to LED. Apply permanent labels indicating wiring changes and lamp type.
• Check environmental ratings under NEC 410.10. For damp or wet locations, select ballasts/drivers and lampholders that are rated accordingly.
• Keep Class 1 line-voltage conductors separate from Class 2 control wiring unless conductors are all rated for the highest voltage present in the raceway.
• Mind case temperature. Do not bury drivers under insulation unless the driver is rated for it.

Testing, commissioning, documentation

• Verify supply voltage at the luminaire. Universal-input drivers still have limits.
• Measure input current and compare to the data sheet. Record amperage by circuit for panel schedules.
• For 0–10 V dimming, confirm minimum and maximum light levels and proper control polarity. Label the control pair at the pull box.
• Document model numbers, date codes, and programming (driver current set point). Keep photos of labels for warranty.

Troubleshooting

• Flicker or strobing: Verify correct ballast factor or LED driver current. Check for mixed lamp types, loose neutrals, and incompatible dimmers.
• No start: Confirm lampholder integrity and wiring. For LED, verify enable leads and correct 0–10 V polarity.
• Buzzing: Swap aging magnetic gear for electronic fluorescent ballasts. See stocked electronic replacements.
• Thermal shutdown: Improve airflow, reduce driver current, or relocate the driver where listed for remote mounting.

Common mistakes

• Mixing lamp types on one channel.
• Setting ballast factor or LED current above rated limits.
• Skipping the luminaire disconnect on double-ended systems.
• Ignoring ambient and case temperature limits.
• Failing to relabel after a retrofit.

Parts to stock + Shop at Revco

• Universal-input LED drivers with field-selectable current.
• Electronic fluorescent ballasts for F32T8 and F54T5HO applications.
• HID gear, including high-pressure sodium ballasts and metal halide ballasts.
• 0–10 V controls, lampholders, and listed luminaire disconnects.
• UL 1598C retrofit kits and permanent labels for conversions.

Need a cross for a discontinued unit fast? Bring the ballast or driver to the counter, or send a clear label photo. We can match specs quickly.

When to call the AHJ or an engineer

• Emergency or egress systems and circuits.
• Large retrofits that alter wiring methods or the luminaire listing.
• Mixed Class 1 and Class 2 control conductors in shared raceways.
• Hazardous, corrosive, damp, or wet locations where ratings are unclear.
• Projects in Nassau or Suffolk where local amendments may change enforcement. Confirm adoption status before ordering.

Safety disclaimer

This article provides general guidance for licensed professionals. Always follow the 2023 National Electrical Code, product listings, and manufacturer instructions. Local adoption and interpretation vary by jurisdiction on Long Island. If any requirement conflicts with product instructions, contact the manufacturer and the authority having jurisdiction.

FAQ

How does ballast factor change light output?
It multiplies rated lamp lumens. A 0.88 factor delivers about 88 percent of nominal output.

Do I need a disconnect in every troffer?
Where the luminaire uses double-ended lamps and the ballast or driver is serviceable, a disconnect is required by NEC 410.71. Verify accessibility.

What is the difference between constant current and constant voltage drivers?
Constant current regulates amperage for LED boards. Constant voltage feeds LED tape or modules that include their own regulation.

Can I reuse old lampholders with a new ballast?
Only if they are compatible and in good condition. Replace brittle or heat-damaged parts.

Why does the driver run hot?
Drivers dissipate heat while regulating power. Check case temperature ratings and provide airflow.

Is Type B TLED acceptable?
Use listed retrofit lamps or kits and apply permanent labels. Confirm acceptance with the AHJ before converting fixtures.

About Revco Lighting & Electrical Supply

Since 1978, Revco Lighting & Electrical Supply has been helping professionals bring their projects to light—literally. As a go-to source for lighting and electrical products across Long Island, NY and nearby areas, we specialize in supporting contractors, builders, and industry experts with practical solutions and dependable service. Whether it’s a complex commercial build or a simple residential upgrade, we’re here to make sure you have what you need, when you need it.

Credits & Contact

Author: Revco Editorial Team - Electrical Content Editor
Technical review: Pending - add approved name/credential
Contact: (631) 283-3600

Sources

1. IAEI Magazine. “NEC Article 410 overview.” Retrieved August 2025. IAEI
2. NFPA. “National Electrical Code (NEC), 2023 Edition.” Retrieved August 2025. NFPA
3. UL Solutions. “UL 1598C Retrofit Kits for Luminaires.” Retrieved August 2025. UL
4. U.S. Department of Energy. “Fluorescent Lamp Ballast Test Procedure (10 CFR Part 430).” Retrieved August 2025. DOE