If a PED had interfered with the high-impedance parts of a circuit that controlled a relay, then I could see it, but by the fact that we are talking about relays acting on their own I assume that has been ruled out
Could that possibly mean high-impedance parts or connections in the wiring close to the relays somewhere between the relays and ELMS?
Could fretting corrosion in connectors be a factor in this case? This kind of corrosion is often not visible to the naked eye. That is why there is an occasional misperception that there is no corrosion problem.
This was found to be a factor in the case regarding unscheduled closing of the shutoff valve i referred to in previous posts.
Regards,
Green-dot