Led Design Guide Page 15 LED Design Guide

2015 Littelfuse LED Lighting Design Guide www.littelfuse.com LED Lighting Design Guide The DOE requirements are similar to those in IEEE C.62.41-2002, IEEE's Recommended Practice on Characterization of Surge in Low Voltage (1000V or less) in AC Power Circuits, with a couple of small differences. DOE's MSSSLC calls out a combination wave and not separate and successive application of the 10kV/10kA surge levels as stated in IEEE C.62.41-2002. The DOE MSSSLC waveform is a combination 1.2/50 s open circuit voltage and 8/20 s short circuit current waveform ( Table 4 ). To perform this test the specified peak current is calibrated on the tester by shorting the output to ground prior to connection to the luminaire. The actual current that gets driven through the luminaire is a result of the combination wave and will likely be lower based on the effective impedance of the luminaire. In turn, the actual current that would run through the MOVs (at the AC input of Figure 3 , or elsewhere) will probably be less than the total current that enters the luminaire, based on available current paths and their effective impedances. This test setup is depicted in Figure 8 . Parameter Test Level/ Configuration Short Circuit Current Peak 0.5kA Open Circuit Voltage Peak 6kV Coupling Modes L1 to PE, L2 to PE, L1 to L2 Polarity and Phase Angle Positive at 90 and Negative at 270 Test Strikes 5 for each Coupling Mode and Polarity/Phase Angle combination Time between Strikes 1 minute Total Number of Strikes = 5 strikes 3 coupling modes 2 polarity/phase angles = 30 total strikes Table 5. DOE MSSSLC 0.5s Rise Time - 100kHz Ring Wave Test Specification Test in LF 10kA Test on whole luminaire A1 = 10kA = A2 (slightly less than 10kA) + A3 Powering Circuitry Luminaire A1 A2 A3 Figure 8. Littelfuse MOVs tested with 2-ohm source impedance per MSSSLC combination waveform. LED Lighting Compliance with Global Standards (continued) 15

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