I am adding a 50 amp sub panel to my shed. I am using thwn 6 awg wire in pvc conduit 2 hots 1 neutral 1 ground. I have installed a ground rod to sub in shed also. Here are the questions I have conduit that leads straight to a sub panel next to main. Can I feed 50 amp sub off a 60 amp sub? Also the 60 amp sub next to main only has 2 hots and a neutral no ground wire it is bonded do I need to bring new sub in shed to main? Also shouldn't my 60 amp sub have a ground to main? I hope I did not confuse anyone. !
ThreePhaseEel is investigating some important aspects, but here's one that I notice.
Your 6 AWG wire, if it's copper, it's good for 65A officially but you can breaker it at 70A. Which is kind of interesting because your subpanel 1 is already 60A and presumably has a 60A breaker in the main panel. What does this mean?
Well, since subpanel 1 is already breakered at 60A, that means you do not need an additional breaker to protect the #6 Cu wiring onward to subpanel 2. You can use thru lugs, subfeed lugs, or simply use 3-void Polaris connectors to split the feeder between subpanel 1 and subpanel 2.
The only way this fails to work is if subpanel 2 a) does not have a main breaker (uh-oh!) and b) has internal busing that can only take 50A. But it would be crazy to use such a small subpanel. I would implore you to return it and get a bigger one. Spaces are dirt cheap, and running out of spaces is painful. Even a modest 6-space panel will have at least 60A and probably 100A busing.