Lighting Surge Protection Modules Design and Installation Guide
LED Lighting Surge Protection Modules Design and Installation Guide Table of Contents Introduction Page 3 Indirect Lightning-Induced Surge 3-5 Regional Differences in Lightning Frequency 6-7 Components That Protect Against Induced Surge Events 8 Modular Solution vs.
LED Lighting Surge Protection Modules Design and Installation Guide Introduction and Indirect Lightning-Induced Surge Introduction LED lighting is increasingly replacing legacy light sources (mercury vapor, metal halide and sodium vapor) in outdoor applications as a result of technological revolutions in LED efficiency (higher lumens per watt), secondary optics (better lenses/reflectors), and greater thermal dissipation.
LED Lighting Surge Protection Modules Design and Installation Guide Indirect Lightning-Induced Surge (continued) Transients Transients Underground Line Figure 2. Indirect lightning strikes can induce magnetic fields in overhead and underground power lines that produce over-voltage transient surges. The surges produced by electrical storms can adversely affect outdoor LED lighting installations.
LED Lighting Surge Protection Modules Design and Installation Guide Indirect Lightning-Induced Surge (continued) Service Equipment Category A: Parts of the installation at some distance from the service entrance Service Entrance Category B: Between Category A and Category C Category C: External part of structure, extending some distance into the building Service Equipment Meter Subpanel Location Category A Outbuilding Service Entrance Location Category B Underground Service Location Category C Fi
LED Lighting Surge Protection Modules Design and Installation Guide Regional Differences in Lightning Frequency The DOE test waveform used to evaluate surge immunity of luminaires used in outdoor lighting (Figure 4) is a combination 1.2x50μs open circuit voltage and 8x20μs short circuit current waveform. To perform this test, the specified peak current is calibrated on the surge generator by shorting the output to ground prior to connection to the luminaire. 1.0 1.0 Front Time - 8 µs 0.8 0.6 0.
LED Lighting Surge Protection Modules Design and Installation Guide Regional Differences in Lightning Frequency (continued) Figure 5. This map of worldwide lightning frequency (courtesy of NASA Global Hydrology Resource Center) depicts the number of lightning flashes/km2/year for various regions.
LED Lighting Surge Protection Modules Design and Installation Guide Components That Protect Against Induced Surge Events Components That Protect Against Induced Surge Events Protecting outdoor LED lighting from lightning induced surges requires diverting high voltage/ current transient interference away from sensitive electronics in the lighting fixture. A variety of surge protective devices (SPDs) are used in outdoor LED lighting to suppress surge energy and minimize surge impact.
LED Lighting Surge Protection Modules Design and Installation Guide Modular Solution vs. a Solution Embedded and Thermally Protected MOV for SPD Safety Modular Solution vs. a Solution Embedded into the Power Supply Unit Outdoor luminaires are easily affected by transient surges inductively coupled into power lines from lightning strikes. IEEE C62.41.2™-2002 categorizes two different exposure levels for outdoor locations (Category C Low and C High) with different suggested surge levels.
LED Lighting Surge Protection Modules Design and Installation Guide Over-voltage Testing in UL 1449 and IEC 61643-11 MOVs are designed to clamp fast over-voltage transients within microseconds. However, in addition to short duration transients, MOVs inside SPD modules can experience temporary over-voltage conditions caused by loss of neutral or by incorrect wiring during installation (Figure 9).
LED Lighting Surge Protection Modules Design and Installation Guide Over-voltage Testing in UL 1449 and IEC 61643-11 (continued) 120 V MOV rated for 150 V rms continuous voltage 120 V Load Figure 10. Loss of Neutral-Ground connection in a standard U.S. split-phase power distribution system. For example, in a standard U.S. 120V AC Line application, two 120V AC power lines (180° out of phase) are commonly fed from a center-tapped 240V transformer. See Figure 10.
LED Lighting Surge Protection Modules Design and Installation Guide Over-voltage Testing in UL 1449 and IEC 61643-11 (continued) IEC 61643-11 Temporary Overvoltage (TOV) Test Compared to surge transients, which are short-duration (microseconds) over-voltage disturbances in AC power lines, temporary over-voltages (TOVs) are longer-duration (milliseconds to minutes long) abnormal high voltages affecting the SPD module.
LED Lighting Surge Protection Modules Design and Installation Guide Over-voltage Testing in UL 1449 and IEC 61643-11 (continued) –– Loss of Secondary Neutral. A broken neutral shifts its potential away and may cause a 1.73× (√3) over-voltage at Line-to-Neutral in the worst case. (A) Normal (B) Lost of neutral L1 L1 U0 U0 N N U0 N1 L3 L2 L3 L2 Figure 12.
LED Lighting Surge Protection Modules Design and Installation Guide Over-voltage Testing in UL 1449 and IEC 61643-11 (continued) End-of-Life/Replacement Indication for SPDs When an MOV becomes overheated due to temporary over-voltage or excessive leakage current, a thermal disconnect may be used to help remove it from the AC circuit. However, with the MOV removed from the circuit, the SPD module no longer provides surge suppression.
LED Lighting Surge Protection Modules Design and Installation Guide L L L + AC/DC N Power L or N Over-voltage Testing in UL 1449 and IEC 61643-11 (continued) N/G - Supply G LED Module LSP10 Wiring Guide, Parallel Connection with End-of-Life Indication Parallel Connection Apply series-connected models of LSP10 Series thermally protected varistor modules (as SPD indicated by an S suffix in the part number) as parallel connections in the lighting fixture.
LED Lighting Surge Protection Modules Design and Installation Guide Coordination between the SPD and the Power Supply Unit Matching the Resistor to the Indicating LED Green/red indicating LEDs are available in the market with different form factors, sizes and ratings. Since the LED connected to SPD is fed by AC line voltage, it is important to choose an LED rated to withstand the full AC voltage in the reverse-bias mode.
LED Lighting Surge Protection Modules Design and Installation Guide Coordination between the SPD and the Power Supply Unit (continued) Typically, compliance testing of luminaires involves 20kV/10kA surges in North America and up to 10kV/5kA1 in Europe. L L MOV2 N MOV1 L MOV2 N G G AC Input LED DRIVER MOV1 SPD UltraMOV™ 25S or TMOV25S™ Series SPD AC Input LED DRIVER UltraMOV™ 25S or TMOV25S™ Series Figure 17. SPD protection schemes that increase the surge immunity of an LED driver.
LED Lighting Surge Protection Modules Design and Installation Guide Power Supply Unit Design Considerations The following steps summarize a design process that helps ensure enough inductance is present between the SPD MOVs and the one in the driver: 1. MOV1 and MOV2 need to be coordinated so that most of surge current/energy flows through MOV1. 2. Select MOVs with VM of MOV1 ≤ VM of MOV2, where VM is the Maximum Continuous Operating Voltage. 3.
LED Lighting Surge Protection Modules Design and Installation Guide Power Supply Unit Design Considerations (continued) F1 L N I1 R1 I2 G I3 MOV2 AC Input LED DRIVER MOV1 SPD Figure 18. Residual voltage and current can damage an LED driver. • Residual Voltage Determined by MOV1; therefore, a varistor with fast response time and low clamping voltage varistor is preferred.
LED Lighting Surge Protection Modules Design and Installation Guide Wiring Guide Wiring Guide L-N-G type, select the model based on rated voltage (Line-to-Neutral) of the power source. The power source’s rated voltage should NOT be higher than the surge protector operating voltage (i.e., 240VAC for Model LSP10240P).
LED Lighting Surge Protection Modules Design and Installation Guide Wiring Guide (continued) L-L-N/G type, Models LSP10240LLX and LSP480LLX are designed to be installed on standard 2-pole, 3-wire single-phase circuits rated 120/240VAC and 277/480VAC respectively. Do not connect them to other circuits.
LED Lighting Surge Protection Modules Design and Installation Guide Installation Guide With IEC color wires (brown/blue) for Class II equipment Line 120V, 240V, 277V, 347V, 480V (Brown) Neutral (Blue) SPD AC/DC Power Supply LED Module LSPxxyyyPX3316, for Class II equipment xx = 05, 10; yyy = 120, 240, 277, 347, 480 Line 120V, 240V, 277V, 347V, 480V (Brown) Brown Neutral (Blue) Blue SPD + – AC/DC Power Supply + – LED Module LSP10yyySX3316, for Class II equipment yyy = 120, 240, 277, 347, or 480
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