57W CFL Street Light Luminaires - BEKA (Pty) Ltd

Technical BulletinAs a result of the various National Energy Efficiency Campaigns, many customers startto believe that CFL lamps, and particularly the 57W CFL lamps, are the most efficientlight sources to be contemplated for energy reduction programs.We wish to remind our customers that the CFL lamp technology rates rather poorly, ifcompared to other available light sources for streetlighting applications.Herewith an overview:Lamp TypesLuminousEfficacyLumenper Wattlm/WMercuryVapourLEDCFLMetalHalideHighPressureSodium50 60 72 88 94We also wish to caution our customers regarding the 57W CFL lamp in use for streetlighting applications, for the following reasons:1. A concern is the fragility of the lamp. Even if the lamp is perfectly positioned inside alamp holder, it is mechanically not suitable to withstand the vibrations as prevail ontop of street light poles. This leads to premature failure of the lamp, which is causedby the disassembly of the glass tubes from its lamp base, into which it wascemented.Vibrations on poles cause the 57W CFLlamp to break between the glass tubesand its lamp base.Mechanical supports, as shown in the picture below, are not only making lampreplacement much more cumbersome, but they also create a “cold spot” on thelamp, which reduces lamp lumen output and the lamp lifetime.

This lamp support does not meet with thelamp manufacturers’ approval because itintroduces a "cold spot" on the glass.2. The 57W CFL lamp needs to be operated by an Electronic Control Gear. Due to thehigh prevalence of lightning strikes in most parts of Southern Africa, clientsneed to be made aware that this could result in failures of ALL ECGs on acircuit, which was hit by lightning. It has to be stated that surge arrestors, builtinto the lighting pole, would not protect the ECG against its failure, since it wouldpresuppose a perfect earth at every pole.No ECG has yet been successfully tested under these conditions, and thereforeBEKA wishes to point out the potential disadvantages associated with the use ofsuch a lamp.To summarise:a. BEKA recommends High Pressure Sodium and Metal Halide Lamptechnologies for Public Lighting, since they represent the most energyefficient light sources for this purpose.b. BEKA does not recommend CFL’s, which require Electronic Control Gears,for use:i. In lightning-prone areas, orii. If mounted on structures, which vibrate.BEKA (PTY) LTD, 13 West View Road, OlifantsfonteinPO Box 120, Olifantsfontein 1665, South AfricaTel: +27 (0)11 238-0000 • Fax: +27 (0)11 238-0180 • e-mail: info@beka.co.zaWebsite: www.beka.co.za