Automation trigger when AC comes back on from my inverter

My connected inverter has a entity called “Battery Grid Charge Current”

This normally sits at 448W, charging my lithium battery using AC.

I have done an automation to notify me if this drops to below 1W using Whatsapp Notification which implies the AC is off. Works perfectly!

But now I want a secondary automation trigger which notifies me once the AC comes back on.
The attributes however only allow for “Above” and “Below” but I want to use the logic that says if the grid charge current changes from 0 to above then I know the AC is back on.
What automation trigger/ YAML code can achieve this?