Q&A: Ask an expert

April 11th, 2014, Published in Articles: Vector

In this article, we talk to IESSA technical adviser Connie Jonker about the claims made about energy-saving lamps; how the user should decide between LED and CFL; whether the wattage and efficiency claims are tested, and on the effect they have on power factor.

Can the end-user have faith in the claims made about “energy saver” lamps?

Connie Jonker

Connie Jonker

CFL lamps are regulated against the compulsory specification VC9091 at present. This specification requires that these lamps be manufactured under a Type 5 product certification scheme, which requires manufacturers to conduct ongoing testing of the quality and performance requirements (including life testing) for these lamps.

Only limited surveillance testing is conducted under the regulatory system operated by the NRCS and SABS product certification mark scheme for CFLs. Therefore, no significant statistics of conformance of CFLs is available to prove that the claims made are valid.

It is estimated that life-time testing is conducted locally on fewer than 100 samples of CFLs per year. This testing is totally insignificant and statistics of these tests would be meaningless if one considers that approximately 40-million CFLs are imported per year, covering numerous brands and types. It is advisable to purchase lamps of known brand names, manufactured by reputable companies with proven records of good quality.

Are the wattage and lm/W figures tested by anyone?

At this stage the only accredited South African test laboratory conducts testing on CFLs. This includes the lm/W characteristics. These tests are, however, only conducted in limited quantities and are mainly conducted for manufacturers or importers who seek approval and letters of authority (LoAs) for these products under the compulsory safety specification, VC9091.

This laboratory still tests LED lamps on a very limited scale. The performance specification for LED lamps, IEC/PAS 62612, does not specify minimum lm/W requirements, but states that the lamps shall have an initial luminous flux no less than 90% of the rated luminous flux.

While there are no mandatory requirements for LED lamps, testing will normally be conducted by the manufacturer and published in manufacturers’ catalogues. In the standard the lumen maintenance test for LED lamps is conducted after 25% of the rated lamp life (with a maximum of 6000 h). The standard gives categories A to E for lumen maintenance after 6000 h, with the requirement that the decrease in light output shall be no more than 10, 20, 30, 40 or 50% from the initial luminous flux value, respectively.

While this standard was published as a “publicly available specification”, it is not certain whether these requirements are being applied by manufacturers yet.

T2_CFL led-lights


Do CFLs create power supply problems?

According to VC9091, CFLs shall have a minimum power factor of 0,5. All electrical and electronic apparatus is also subject to EMC/EMI standards in accordance with Government Gazette No. 26869, 5 October 2004.

This requires that electrical lighting and similar equipment (including CFLs and LEDs) shall comply with the requirements of SANS 215 (CISPR 15) for electromagnetic emission (EMC), and IEC 61547 for electromagnetic immunity (EMI). It is the responsibility of manufacturers and importers to ensure that these requirements are met.

In view of the limited test facilities in South Africa (only one accredited commercial test laboratory), one can only assume that the testing of these products is not at the level it is supposed to be.

How can the end-user decide between CFLs and LEDs?

The choice between CFLs and LEDs depends on many factors, some of which are:

  • Affordability: does the user have the financial means to buy the LED product, which is claimed to have a life expectancy of about eight times that of a CFL, but also at a related price? In the case of a retrofit, the lamp type is most suitable for the luminaire in which it will be fitted is a deciding factor.

In terms of performance, the photometric characteristics often determine the user’s choice. LEDs are so versatile that they can be used for almost all lighting applications, general lighting, flood lighting, task lighting etc.

  • Lamp efficacy: LEDs are certainly the choice of better energy efficiency. In view of their lifetime claims of up to 50 000 h, these lamps are the preferred choice for luminaires mounted in locations where accessibility for maintenance and lamp replacement is difficult.

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