8 D

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APPENDIX 8D. HOT SHOCK IN INCANDESCENT REFLECTOR LAMPS

TABLE OF CONTENTS

8D.1 INTRODUCTION AND PURPOSE ...................................................................... 8D- 1

8D.2 IMPACT OF STANDARDS .................................................................................. 8D- 2

REFERENCES ................................................................................................ ......................... 8D- 3

LIST OF FIGURES

Figure 8D.1.1 Filament after Hot Shock; Shorted Coils Visible .............................................. 8D-2

LIST OF TABLES

Table 8D.2.1 IRL Lifetime Reduction at CSL 1 ....................................................................... 8D-28D

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APPENDIX 8D. HOT SHOCK IN INCANDESCENT REFLECTOR LAMPS

8D.1 INTRODUCTION AND PURPOSE

Incandescent reflector lamps (IRLs) produce light when a thin tungsten wire (filament) inside the lamp is heated to a temperature high enough to cause incandescence , which is theproduction of electromagnetic energy in the visible spectrum due to the movement of hightemperature molecules. IRLs that feature halogen or halogen-infrared (HIR) technologies incorporate a filament that is contained within a small capsule inside of the lamp. In order for the filament to fit inside of the capsule while being of the necessary length to allow the lamp to obtain its rated performance, the filament must be coiled upon itself.

Because the filament is thin, it is subject to movement due to forces (such as sudden jolts) applied to the lamp. The coiled structure of the filament brings it in close proximity with other parts of itself and external forces to the lamp can cause parts of the filament to touch each other.

If thi s self-contact occurs when the filament is heated and producing light, the areas that contact each other can weld together and cause an electrical short. Electrical current is higher through a short ed circuit and produc es a higher temperature that subsequently reduces the life of the lamp. This phenomenon is known as hot shock

. Figure 8D.1.1 shows an image of a filament that has experienced hot shock; the darkened regions are where the coils have been shorted. While certain kinds of IRLs contain filament supports to reduce the probability of hot shock, halogen and HIR capsules do not contain such supports because they would reduce lamp efficacy. 1

Hot shock can occur when an IRL is installed into an electrical socket that is active, which causes electricity to flow through the lamp before it is completely seated by the installer. 2
Hot shock can also occur during the movement of active lamps. Thus, one way to avoid hot shock in IRLs is to deactivate the electrical socket during lamp installation or during lamp position adjustments on movable fixtures (such as movable spotlights). If the electrical

connec tion cannot be deactivated, then the lamps should be installed or moved as smoothly and carefully as possible to reduce the risk of hot shock.

Because lamp lifetime impacts the life-cycle cost (LCC) analysis and hot shock shortens

the life time of IRLs, the U.S. Department of Energy (DOE) evaluated the possible impacts of hot shock on potential standards.8D

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Figure 8D.1. 1 Filament after Hot Shock; Shorted Coils Visible 3

8D.2 IMPACT OF STANDARDS

DOE analyzed the impacts of standards at the candidate standard level (CSL) considered for IRLs with respect to shortened lifetime as a result of hot shock. Because the LCC of a product depends directly on the product lifetime, the occurrence of hot shock in an IRL will impact the LCC savings to the consumer. Switching to a more efficacious IRL that operates for a longer time will result in an increase in the residual value of the lamp, delivering greater LCC savings to the consumer. Therefore, DOE performed an analysis to determine how much the lifetime of IRLs at CSL 1 could be shortened before it negatively impacted LCC savings.

As discussed in chapter 5 of this preliminary technical support document (TSD ), DOE evaluated two baselines for IRLs, a 1, 500 -h ou r improved halogen lamp and a 3,000-h ou r halogen-infrared (HIR) lamp. To obtain minimum lifetime values, DOE reduced the lifetime of lamps at CSL 1 for all scenarios with positive LCC savings until those savings became negative. The results of this analysis are shown in Table 8D.2. 1

. IRL lifetime could be shortened by 48 percent in the commercial sector and 43 percent in the residential sector before the consumer experiences negative LCC savings at CSL 1 relative to the 1,500-hour improved halogen

baseline. Note that the LC C results for the 3,000-h our HIR baseline were negative and thus were not included in the hot shock analysis ; this is indicated by “N/A” in the table below.

Table 8D.2. 1 IRL Lifetime Reduction at CSL 1

Baseli ne Commercial Sector Residential Sector

Lifetime (hours) Percent

Reduction Lifetime

(hours) Percent

Reduction

60 W PAR38 1

, 500 h our Improved Halogen 2

, 302 48 % 2

, 509 43%

60 W PAR38 3

, 000 hour HIR N/A N/A N/A N/A8D

- 3 REFERENCES

1 GE Consumer & Industrial Lighting. 2009. No. 63, Appendix 5 at p. 1

. This attachment to a written comment, Document Number 63 Appendix 5, is available in Docket # EE

– 2006

– STD–

0131

. For more information, contact Brenda Edwards-Jones at (202) 586-2945.

2 GE Consumer & Industrial Lighting. 2009. No. 63, Appendix 5 at p. 1

. This attachment to a written comment, Document Number 63 Appendix 5, is available in Docket # EE

– 2006

– STD–

0131

. For more information, contact Brenda Edwards-Jones at (202) 586-2945.

3 National Electrical Manufacturers Association. 2009. No. 81 at p. 27. This written comment, Document Number 81, is available in Docket # EE

– 2006– STD– 0131

. For more information, contact Brenda Edwards-Jones at (202) 586-2945.