I have been reading your thread and have a few questions. I have a main that has 3 breakers: 100A that feeds to a sub and runs most the house and (2) sperate 50A's for the A/C and Oven. Currently the 100A sub has all the nuetrals and grounds tied to the same bar. This sounds incorrect per this thread. The sub is run via SE type 3 wire that has 2 hots and (2) seperate grounds (not in jackets). What are my options here: Can I use one of the 2 frounds as the neutral or will I have to reqire for true 4 wire to have the neutral and grounds seperate at the sub? Doesn't the NEC code say I can use the SE type wire in this manner? The house was built in 1982. Thanks for all the responses. C