Hi:
I've recently had a need to re-visit the application of EFT pulses on AC
power cords. Although the current version of the std. (1st ed.,1995) discusses
assymetric application of the EFT pulse (Section 6.2), the std does not
explicitly describe that the pulse application must be done on one conductor
at a time. Considering Figures 4 and 11, it would appear that pulses can be
applied to the protective earth (ground). Question is, is simultaneous
application of the burst (in common mode) a valid and necessary test case?
I believe the answer is yes for the following reasons:
- I/O lines are exposed to EFT via the capacitive coupling clamp in true
common mode, so why would power cords be treated differently?
- for the same reasons that I/O cables are exposed to common mode burst
events in reality, power cords should be exposed to common mode events.
- A number of commercial stds, i.e. ETS 300-342-2, describe common mode
application of the burst.
Anyone else with comments on this?
Regards,
Geoff Skanes
EMC Engineer
Nortel Technology
RTP, NC
