Why some RCDs/GFCIs are damaged if used in reverse

With recent regulation changes to address the issue of RCDs/GFCIs being damaged when used in solar power systems that can feed power back to the supply network.

The issue is that some (not all) RCDs/GFCIs have a short duty cycle coil designed to be pulsed at high current very briefly to trigger the breaker. They can rely on the breaker tripping to kill power to the coil. If the breaker doesn't trip or the power is being supplied from the wrong side, the trip coil and its drive circuitry will potentially be energised long enough to cause damage.