8D-i APPENDIX 8D. H OT SHOCK IN INCANDESCENT REFLECTOR LAMPS

TABLE OF CONTENTS

8D.1 INTRODUCTION AND DEFINITION................................................................. 8D-1 8D.2 IMPACT OF HOT SHOCK ON LI FE-CYCLE COST SAVINGS ....................... 8D-1 8D.3 AVOIDING HOT SHOCK..................................................................................... 8D-2 REFERENCES ..................................................................................................................... .... 8D-3

LIST OF FIGURES

Figure 8D.1 Filament After Hot Shock; Shorted Coils Visible ................................................ 8D-1

LIST OF TABLES

Table 8D.1 Commercial-Sect or IRL Lifetim e Reduction for Negative LCC Savings ............. 8D-2 Table 8D.2 Residential-Sector IRL Li fetime Reduction for Negative LCC Savings ............... 8D-2APPENDIX 8D. HOT SHOCK IN INCANDESCENT REFLECTOR LAMPS

8D.1 INTRODUCTION AND DEFINITION

Incandescent reflector lamps (IRL) produce light when a th in tungsten wire (filament) inside the lamp is heated to a temperature high enough to cause incandescence , which is the production of electromagnetic energy in the vi sible spectrum due to the movement of hightemperature molecules. Incandescent reflector la mps that feature haloge n or halogen-infrared (HIR) technologies incorporate a f ilament 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. Because the filament is also coiled (bringing the filament into close proximity with other parts of itself), movements of the filament due to external forces can cause parts of the filament to touch each other. If this 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 the short, produc ing a higher temp erature that subsequently reduces the life of the lamp. This phenomenon is known as hot shock

. Figure 8D.1 shows an image of a filam ent th at has experienced hot shock; note the darkened region where coils have been shorted. While certain kinds of IRL contain filament supports to reduce the probability of hot shock, halogen and HIR capsule s do not contain such supports because they would reduce efficacy. i

Figure 8D.1 Filament After Hot Shock; Shorted Coils Visible ii

8D.2 IMPACT OF HOT SHOCK ON LIFE-CYCLE COST SAVI NGS

Because the life-cycle cost (LCC) of a produc t depends directly on the product lifetime, hot shock in an incandescent reflector lamp will impact the life-cycle cost. The LCC savings that a consumer can achieve when switching to a more-efficient IRL thus also depends on the effective lifetime of that more-efficient lamp; a more-efficient product will incur more operating cost savings and thus deliver gr eater LCC savings to the consum er if it operates for a longer

8D-18D-2 time. The U.S. Department of Energy (DOE) thus attempted to determine the minimum lifetime the IRL analyzed in Chapter 8 (life-cycle cost an d payback period analysis) must have in order to deliver positive LCC savings to the consumer. To obtain these minimum lifetime values, DOE utilized the LCC spreadsheet described in Appe ndix 8A and reduced the lifetimes of all lamps with positive LCC savings until those LCC savings became negative. The results of this analysis are shown in Table 8D.1 for the commercial sector and in Table 8D.2 for the residential sector. The percent reduction colum n show s the percent reduction in IRL lifetime that would have to occur (due to hot shock or other causes) before the consumer experiences negative LCC savings. Note that some lamps analyzed by DOE gave negative LCC savings to consumers even when operated for their full rated lifetimes; these la mps are indicated by “N/A ” in the tables.

Table 8D.1 Commercial-Sector IRL Lifeti me Reduction for Negative LCC Savings
90W Baseline 75W Baseline 50W Baseline

Efficacy Level Lifetime Percent Reduction Lifetime Percent Reduction Lifetime Percent Reduction EL1 N/A N/A N/A N/A N/A N/A EL2 - 6,000 hr 2587 57% 2587 57% 3277 45% EL2 - 3,000 hr 2242 25% 2242 25% N/A N/A EL3 1897 37% 1897 37% 2932 2% EL4 - Short-life 1897 24% 2242 10% N/A N/A EL4 1897 53% 2242 44% 3277 18% EL5 - Short-life 1897 24% 1897 24% N/A N/A EL5 1897 55% 1897 55% 3277 22%

Table 8D.2 Residential-Sector IRL Lifeti me Reduction for Negative LCC Savings
90W Baseline 75W Baseline 50W Baseline

Efficacy Level Lifetime Percent Reduction Lifetime Percent Reduction Lifetime Percent Reduction EL1 2443 2% N/A N/A N/A N/A EL2 - 6,000 hr 2355 61% 2532 58% 3233 46% EL2 - 3,000 hr 1999 33% 2177 27% 2977 1% EL3 1644 45% 1821 39% 2621 13% EL4 - Short-life 1733 31% 1910 24% 2977 1% EL4 1733 57% 1910 52% 2977 26% EL5 - Short-life 1644 34% 1910 24% N/A N/A EL5 1644 61% 1910 55% 3243 23%

8D.3 AVOIDING HOT SHOCK

Hot shock can occur when an IRL is installed into an electrical grid or socket that is active, which causes electricity to flow through th e lamp before it is completely seated by the installer. iii Hot shock can also occur during the move ment of active lamps. Thus, one way to avoid hot shock in IRL is to deac tivate the electrical grid or so cket during lamp installation or during the aiming of lamps on movable fixtures (suc h as movable spotlights). If the electrical connection cannot be de-activate d, then the lamps should be inst alled or moved as smoothly and carefully as possible to reduce the risk of hot shock.8D-3 REFERENCES

i GE Consumer & Industrial Lighting. 2009. No. 63, Appendix 5 at p. 1. This attachment to a written comment, Document Number 63 Appe ndix 5, is available in Docket #EE–2006–STD– 0131. For more information, contact Brenda Edwards-Jones at (202) 586-2945.

ii National Electrical Manufacturers Association. 2009. No. 81 at p. 27. This written comment, Document Number 81, is available in Do cket #EE–2006–STD–0131. For more information, contact Brenda Edwards-J ones at (202) 586-2945.

iii GE Consumer & Industrial Lighting. 2009. No. 63, Appendix 5 at p. 1. This attachment to a written comment, Document Number 63 Appe ndix 5, is available in Docket #EE–2006–STD– 0131. For more information, contact Brenda Edwards-Jones at (202) 586-2945.