Linking 2 TB3 ports on the same macbook

[mihai1880]

I know this sounds silly, but TB3 is the first port with both ends of the cable with male connectors.
If one would accidentally connect 2 ports with one cable, would that damage the unit or nothing would happen?

 

[killawat]

Using the supplied Apple charging cable that is correctly wired, nothing bad. I think the Mac tries to charge itself.

 

[xraydoc]

I know this sounds silly, but TB3 is the first port with both ends of the cable with male connectors.
If one would accidentally connect 2 ports with one cable, would that damage the unit or nothing would happen?

TB1 and TB2 also had cables that could potentially be looped back in to the same MacBook.

I don't, however, know what would happen. Hopefully nothing but I guess there's the potential for damage.