IEC 60893-3-3 (UPGM203) vs NEMA LI-1 GPO-3 are the same material: alkali free fiberglass felt+flame-retardant unsaturated polyester thermosetting laminated board; Just two different regional standard codes, not two different materials
-UPGM203=IEC International Standard Grade (commonly used in Europe)
-GPO-3=NEMA US Standard Grade (commonly used in North America and UL projects)
1. Do not mistakenly think that UPGM203 and GPO-3 are two different types of boards; The performance of qualified products is basically aligned, and the difference comes from the testing method and unit system, not the material formula itself.
2. Low price and low-quality board: Although the nominal UPGM203/GPO-3 is used, a large amount of calcium carbonate filler replaces fiberglass. Although the density is similar, the arc resistance and CTI may not meet the standards.
3. Neither IEC nor NEMA standards specify the minimum proportion of fiberglass
