What's the problem with electronic ballasts for street lighting lanterns?

A statistic compiled by the Engineering Department of Tenaga Nasional Berhad (TNB) in August 2002 had shown that between January 2001 and January 2002, more than 38% of electronic ballasts (EB) installed in street lighting lanterns nationwide had failed during operation. By August 2002, out of 82,000 EB installed nationwide, 53% became faulty. In some cases, the EB were found to be defective within days of being installed. It was suspected that the EB became faulty due to either vibration, shock or bump experienced during the transportation and handling of the EB, direct or indirect lightning strikes on the street lanterns or possibly inadequate design. A research project was undertaken by TNB Research Sdn Bhd (TNBR) to investigate the root causes of EB failures and to recommend improvements to the EB design. Samples of EB were obtained from the TNB vendors and from several sites around the country. The samples were subjected to various type tests and post-mortem analysis involving electrical and thermography tests. This paper presents the results of the tests performed and the recommendations made to TNB.