UL 1449 5th Edition and IEC 61643 are both representative international standards for the safety and performance of surge protection devices (SPDs). The main differences between each standard, including focus, classification method, and test method, are summarized below.
Classification method
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UL 1449 5th Edition : Classifies SPDs into Type 1, 2, 3, 4, and 5 according to installation location (e.g. transformer secondary side, distribution board, terminal, etc.). Focuses on the product installation environment and safety.
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IEC 61643 : Classified into Class I (for direct lightning strikes), Class II (for distribution protection), and Class III (for terminal equipment protection) according to the experimental waveform (e.g. 8/20μs, 10/350μs). Surge protection performance is the main criterion.
Key items for evaluation and testing
|
division |
UL 1449 5th Edition |
IEC 61643 |
|
Main focus |
Numerous product safety, case, and disconnector tests |
Surge protection performance (withstands high energy surges) |
|
Classification criteria |
Installation location (Type 1, 2, 3, 4, 5) |
Experimental waveforms (Class I, II, III) |
|
Test waveform |
1.2/50μs & 8/20μs combination waveforms |
Class I (10/350μs), II (8/20μs), etc. |
|
Protection class |
Voltage Protection Rating (VPR) |
Up (Voltage Protection Level) |
|
Rated Items |
MCOV (Maximum Continuous Operating Voltage), etc. |
Up, In (rated discharge current), Iimp (impulse current), etc. |
|
Test method |
Repeated testing with many samples, multiple tests on the disconnector, relatively low surge levels |
More surge waveforms, higher surge current values, and more repetitive surge tests |
|
etc |
Focused on North America, emphasizing product safety |
International (especially European) focused, with an emphasis on performance and durability |
Summary of Standard Differentiators
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UL 1449 places a lot of emphasis on the safety of the device and its suitability for the installation environment (overheating, short circuit, durability, etc.).
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IEC 61643 places emphasis on the rigor of protective performance under actual lightning/surge conditions and repeated high-energy testing.
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Both standards test SPDs to ensure they are compatible with each country's utility equipment, but the testing methods and focus are different.