I understand that it is acceptable to place two circuits on one breaker (assuming the load is within limits) by pig-tailing as opposed to placing two cables under the breaker terminal. However, can the same thing (pig-tailing) be done with the neutrals or grounds, when the buss bar is full and a new circuit is being added? It seems to me that to do so would require that the pig-tail be a greater gauge than the two wires to which it is connected.
