Colleagues, I have several times got into debates over the appropriate ESD severity levels for plastic-enclosed products. This class includes cameras, remote controls and mobile phones.
Only the air-discharge test is applicable (there being no exposed metal to make contact to), and generally the designer's goal is to protect the product by preventing flashover from occuring (by using insulation and labyrinths). So what voltage does one design/test to? IEC 801-2:1984 defines severity level 4: 15kV, which is intended for dry (5%RH) synthetic environments. However, IEC 801-2:1991 and EN55024-2 only seem to specify AIr Discharge at 8kV. I know of several handheld products where the manufacturer tested to 8kV and regarded this as good enough. So much for the standards. What really matters is the product shall work and not blow up in the customer's hand. The literature suggests that a human body under the most extreme conditions can reach about 25kV (presumably limited by corona discharge). Should this be the target level? Does anyone know of any standards beyond IEC that shed any light? What do the military do? Is anyone aware of manufacturers having internal standards that go up to or beyond 15kV? I will be happy to collate any replies sent to me and re-post them as a summary to the group. --Paul Reilly-- PA Consulting Group Cambridge UK, Tel UK + 1763-261222 [email protected]
