Momentary Electrical Spikes

What is your incoming voltage.?? 415V, 3.3KV, 33KV or 132KV???

Both Discrimination and co-ordination are big and complex issues. Companies such as ABB, Sprecher and Schuh or Schnieder have a lot of expertise that should help you.

Your secondary breakers are rated at a certain KVA in-rush on the power ladder. There are engineering safety designs configured into the power ladder design for releasing the latch in-case of overload. It is good your system did trip out as it did. I would rather have a secondary main stop the in-rush before it takes out real critical equipment. Yes you can put in a simple surge suppressant on all your critical equipemnet, how ever it does get pricey. I would reccomend not just installing a single suppressor, but to have them at the disconnect of the individual critical equipement. I would rather have each piece protected and not have the system completly down due to an in-rush. That is why certain types of breakers are installed and are designed into the power grid system of your particular structure.

I have delt with a company in Lake Park Fl called Meter treater 561-845 2007. They are experts in surge protection and may be able to help you analyse your problem.

You have to find out which relays operated to trip the secondary breakers. This could be either the undervoltage, overvoltage, earth fault, differential or reverse power relays. Once the relay is determined, add a time delay of about .05s to this relay before it trips the circuit breaker. The system should stay stable during transient power surges.