Solution:

We test to the EFT ±1 KV limit. EMC tests are done to the limits listed in the Standards, in this case the Light Industrial Standard, EN61000-6-1. In the EMC world there are no required “safety margins”. The EFT requirement is ±1 KV on the signal lines. The USR602 was tested to the limits identified. We can’t guarantee beyond that. EFT Burst was tested in accordance with the Light Industrial Standard to 1 kV on the signal ports. See attached.