Hello
We manufacture Industrial control products and have been listing them to UL508 and UL1604 for several years. These are typically products with plastic enclosure designed to be mounted on a panel. Most of these products have LCDs and PCBs inside and the plastic enclosures have opening to show the LCD. We have been using plastics rated to V0 and polyester overlays rated to HB without any problems.
Recently on our new products because the plastic enclosure has an opening (to show the LCD and touchscreen), UL asked us to use plastics rated to V5. This is a big problem since we will have to change the entire supply chain for plastics and so on.
Has anybody else had similar problems? Since the opening is already covered with LCD and PCB (Fr4 or better) anyway, why is UL concerned about fire coming out from the opening? What is the solution?
Thanks in advance.
We manufacture Industrial control products and have been listing them to UL508 and UL1604 for several years. These are typically products with plastic enclosure designed to be mounted on a panel. Most of these products have LCDs and PCBs inside and the plastic enclosures have opening to show the LCD. We have been using plastics rated to V0 and polyester overlays rated to HB without any problems.
Recently on our new products because the plastic enclosure has an opening (to show the LCD and touchscreen), UL asked us to use plastics rated to V5. This is a big problem since we will have to change the entire supply chain for plastics and so on.
Has anybody else had similar problems? Since the opening is already covered with LCD and PCB (Fr4 or better) anyway, why is UL concerned about fire coming out from the opening? What is the solution?
Thanks in advance.
