On June 5 Jerry Martin wrote:
We are designing a product that will be used in a Network Interface Device (NID) that mounts on the outside wall of a house. The enclosure will be a 5V material and the customer will not have access to the network circuitry. We would like to submit the product to UL 1459 (knowing that it will be replaced by UL 1950 in April, 2000). With so much energy available during the overvoltage test, we're concerned that etch will open. Is it o.k. if the etch opens and we pass the dielectric strength test afterwards? The enclosure will be covered with cheesecloth and there is no way for flaming particles to get out. Thank you for your replies, Jerry Jerry, Having etch open is not considered a passing condition. There have been discussions where people try to use etch as a fuse. Safety agencies do not accept that construction since there can be manufacturing inconsistancies. Sometimes the etch can peel off the board and short something else, causing even a worse hazard. I would be concerned about an etch that would blow before the wiring simulator fuse, usually a Bussman MDQ 1.6 A Time Delay fuse. Opinions expressed are my own, and not those of my employer. Eric Petitpierre Pulsecom Herndon, VA [email protected]
