I am adding 350 sf to my little so. Calif. house. (master bath and adding to the bedroom) Thanks for your help on my heating questions. The heating has been solved. I put in hydronic baseboards with the water coming from a tankless water heater.
Now, I put in a new electrical sub-panel. Ran a conduit and some #10 wires from the main. The inspector says to put another buss bar in the sub-panel and hook all of the bare coppers to that, and the green #10 from the main. Also the ground wire which is clamped to the water pipe. So, I guess that’s it. I’ll hook all of the white (neutrals) to the existing buss which must be isolated from the box I would guess.
Does this sound right? I remember reading about cutting the bond between the neutral and ground busses in a sub-panel.
I put in a arc-fault breaker for the bedroom circuits. What is that for?
Replies
yes thats right. the arc fault in bedroom because its code.
You are right. The only place the ground wires (bare or green) and the neutrals (white, or sometimes black if large) are connected together is in the main panel. Everywhere else in the system they are to be separate, and that includes the sub panel. So, in the sub panel there must be two buss bars, the one grounded to the box receives all the ground wires and carries them back on the ground wire to the main panel, and the buss that's isolated from the box which receives the neutrals and carries them back to the main panel on a conductor different from the ground.
Arc fault circuit breakers are newly required in bedroom circuits. The requirement is in response to fires started while people slept caused by arcing within the circuit. An arc fault circuit breaker detects when arcing occurs (as from a loose wire in an outlet, for example) and trips the breaker. They also trip on current overload as regular breakers do.