This command sets the selected grid object as the construction grid. The previously active grid, whether the home grid or another grid object, is consequently deactivated. This command is available only when a grid object is selected.
To activate a grid object:
Grids and Snaps
Activate Grid Object. If using the Alt menu system, use the Scene menu instead.
The grid object changes to show its internal grid structure. Except for its main axes, the home grid disappears in all viewports.