Hello: I stumbled across your forum and found a question that was close to mine, but have a more detailed query. I am wiring a shop/apartment. The building has a 200 amp service panel. The main loads (a/c, range) and dedicated loads (fridge, smoke detectors, etc) are branch circuits on the main service panel. I purchased a 125 panel at home depot (it looks like a main panel because it has a 125 amp breaker at the top). I put a 100 amp breaker in the main panel and connected the two panels using #2 copper. The two wires from the 200 amp main panel go to the 125 amp panel in the sub-panel. A #2 wire connects the main neutral bus to the sub neutral bus. I installed a separate ground bus in the sub panel, bonding it to the sub panel using machine screws; the ground bus is connected to the main panel's neutral/ground bus using #2 copper.

I wired a number of branch circuits into the shop/apt from the subpanel. My concern is in knowing that the sub panel's neutral bus is not bonded to the box. I have looked at the box (a GE 125 amp, 24 circuit load center) and I don't see any obvious connections that would bond the neutral bus to the box. I did not disconnect anything that would have bonded the neutral to the box. Does this sound reasonable? My logic is that is is unlikely that the neutral bus would be bonded to the box by default, but I am looking for some reassurance that my thinking is valid. As I am looking for a safe installation, any advice would be deeply appreciated.

The neutral in a subpanel is not to be bonded to the metal box, or equipment ground. So sounds like you did exactly as should be done.

The neutral and equipment ground only gets bonded at the location of the Main Service Disconnect, which sounds like your Main Panel.

Thanks for the response. It puts my mind at rest as I continue the project. I have read your other responses and they sound very good and are not condescending.