Influence of cold starting on the life of T5 fluorescent tubes and CFLs

The paper presents an experimental investigation of the parameters that influence the life of T5 and compact fluorescent lamps (CFLs) operating with instant start ballasts. Measurements were carried out during the starting period of the systems as well as during operation. Results reveal that cold ignition has a strong impact on the life of the systems. Lamp life was found to be less than 5,000 operating cycles. The same lamps operating with ballasts providing warm start achieved a life of more than 70,000 starts. Five groups in different operating cycles were tested. Starting time, starting voltage and inrush current were measured during the starting period and their influence on lamp life was examined. The paper also investigates the hypothesis that in every ignition a constant quantity of emissive material is lost and another quantity is also lost during every hour of operation. In general, the results establish that predictions for the lamp life of these systems cannot be drawn, because of the absence of deterministic effects that can be attributed to fluorescent lamps.