The push button RCD fitted on the Classic series is of the type known as “active”. An active RCD trips on either an internal fault or when there is an external power interrupt. This was intended to be an additional safety feature. If someone reconnected the external power, you would need to manually need to reset the RCD. Most boats have “passive” RCDs – meaning they do not trip on an external power interrupt and onboard systems (e.g. Battery Charger) continue to operate normally when external power is restored. (What I found annoying was that a momentary power interrupt, not infrequent in many Marinas, left my battery charger off until I returned to the boat and reset it!).
So…I had my electrician replaced the old breaker with a new one that is unaffected by power interruptions. Since the installation I have had no issues. Understand that my boat is docked in the states and operates with 110 volts ac shore power.