What is the transverse/common mode interference?
A. Some protection against these two forms of interference is not as effective as you may be led to believe. Surge clippers and RFI filters will not provide a complete cleaning for the power line. Also expensive ultra isolating transformers will provide little attenuation of high-energy transverse spike and will attenuate common mode noise no better than any conventional isolating transformer, provided that earth and secondary neutral lines are linked, which is always desirable.