I’m switching my dryer outlet from 240 30amp to 125 30amp because that’s what the dryer I have mates with. Pulled the old four prong off and expected to find two greens a white and a black, instead I’ve got a red, something that is either black or green a white and a braided copper wire unsheathed.  I believe the last is the system ground the white or neutral is the appliance ground and either one of the other two is hot. Is this correct?