I have a surface mount subpanel in my garage which has been present since I bought the place (I didn't wire it up). I am thinking about adding a circuit to it, so I pulled the cover to take a look at how it's wired and I'm wondering if the panel ground is wired correctly.
This subpanel sits exactly on the back side of the main panel. There are 6AWG wires feeding the panel from a 60A breaker in the main panel, they've run 6AWG for both 120v legs and the neutral leg, there is no ground wire run or even a ground bar in the subpanel.
The subpanel is physically connected to the main panel via some type of very short (1-3") metal conduit nipple. I am assuming the "ground" exists by this connection.
My question is, is this a valid way to ground the subpanel? I know subpanels are not supposed to have neutral and ground bonded, but it is in this panel. Not sure if that is OK since the panels are physically connected via the conduit nipple.
Any advice? Thanks in advance.