Loads fuel into equipment grid burner generators, for example Equipment+: Portable Engine, Fission and Fusion or Battery Pack.

Automatically pulls fuel from a player's, a train's or a vehicle's inventory (including fuel inventory, if using compatible fuel).

It checks back when it expects half the fuel in the burner will be exhausted (assuming the burner is running at full power) to attempt to load more fuel; if there's no fuel available, it checks every tick for fuel to arrive.