Universal Lighting Technologies

Linear Fluorescent Lighting Systems Maintenance Guide

Suggestions for Fluorescent Fixture Maintenance

Preventing a problem from occurring is always more desirable and economical than fixing it later. A scheduled program of preventive maintenance can save money while maintaining productivity and safety.

By using the following maintenance suggestions, the ballast will have a longer, more trouble-free life. There are many lighting maintenance contractors and electrical contractors who will economically perform a scheduled maintenance program.

To obtain normal ballast life and maximum efficiency from a fluorescent lighting installation, fixtures should be periodically inspected for:

  • Lamps cycling on and off
  • Heavy lamp end discoloration
  • Dim lamps
  • Slow-starting lamps
  • Inoperative lamps
  • Dust or dirt

The significance and correction of these conditions can vary with the type of lamp and ballast used, and are covered in greater detail later in this guide. The following general maintenance procedures apply to all lamp and ballast types and will help ensure maximum performance and long component life:

  • Lamps should be replaced when they reach 70%-80% of their rated life. Your lamp supplier has additional information available regarding lamp maintenance procedures.
  • Lamps, reflectors, and lenses should be cleaned periodically as an accumulation of dirt, combined with high humidity conditions, can impede starting.
  • Lamps should be checked to be sure the proper lamp type is being used, according to the information on the label of the installed ballast. Many lamp types currently offered are interchangeable physically, but not electrically, such as T8 and T12 rapid start lamps.
  • Line voltage should be checked at the fixture and compared with the ballast rating to be sure it is within the prescribed limits.
  • Lamps cycling on and off may be a warning that the ballast is operating too high a temperature, causing the automatic resetting thermal protector to deactivate the ballast when the temperature limit is exceeded. Detailed information and corrective action can be found elsewhere in this guide.
  • Make sure that lamp socket spacing and mounting distance from grounded fixture or metal strip are correct and lamps are properly seated. (See Appendix C)
  • Make certain polarity is correct. (See Appendix D)
  • Be sure the fixture and ballast(s) are properly grounded. (See Appendix E)

Safety First

Ballast replacement and lighting maintenance present the possibility of exposure to potentially hazardous voltages and should be performed only by qualified personnel. All installation, inspection, and maintenance should be performed only with the entire circuit power to fixture or equipment turned off.

All ballasts and fixtures must be installed and operated in compliance with the National Electrical code, requirements of Underwriters Laboratories, Inc., and all applicable codes and regulations. This includes, but is not limited to, proper grounding of ballasts and fixtures as well as prescribed branch and total circuit protections.


This concise guide provides a logical sequence and procedures for troubleshooting and correcting the most commonly encountered problems in a typical fluorescent lighting system. There are many specialized ballasts, lamps, fixtures and lighting controls which are not specifically addressed. The troubleshooter should always check for special conditions which might exist in an installation, creating an exception to the rules or a potential safety hazard.

Proper maintenance of any lighting system is essential to maintain levels of illumination necessary for productivity, merchandising, visual comfort, safety and security. If an individual component fails and is allowed to remain in the lighting system, costly damage to other components can result. Major repairs can often be avoided by simple maintenance procedures and timely attention to small problems, such as replacing burned-out lamps.


Any electrical system presents potential hazards. Troubleshooting or maintenance procedures should only be performed by qualified personnel. Ballasts and other components, as well as the fixture, must be grounded. All components must be installed and operated in compliance with the National electrical code and all local electrical ordinances.

Protect the Ballast

A ballast, like any electrical device, generates heat. To ensure maximum ballast life, it is imperative that operating temperatures be kept as low as possible. Burned-out or failing lamps, or high temperatures in or around the fixture, can cause the ballast to overheat, resulting in premature failure. For additional information regarding heat and recommendations for maximizing ballast life and performance, consult Universal Lighting Technologies' catalogs.

Most fluorescent ballasts incorporate internal automatic-resetting thermal protection, which deactivates the ballast should it overheat. Normal operation resumes once the ballast has cooled sufficiently. Cycling will continue until the cause of overheating is corrected.

Ballasts manufactured before 1984 may contain non-resetting thermal protection, which permanently deactivates the ballast, or no thermal protection at all.

For Additional Assistance

If additional troubleshooting assistance is required, or you have any questions regarding your lighting system, we’re ready to help! Call Universal Lighting Technologies’ Technical Engineering Service™ Department at 1-800-BALLAST.