Originally Posted by suemarkp
I guess you learn something every day. I thought the primary was one wire and the "neutral" was a common wire used for both the primary and secondary. Is a common wire ever used in power distribution for one side of the primary and secondary?
Around here the primary and secondary neutral are one in the same.
I just looked at several transformers. Both ones with single primary terminals and those with 2.
Those with one have a single lead from the primary lug to the cutout.
One the secondary they have 3 terminals (all appear to be insulated). But below the CT is a ground lug to the case. A bare wire goes form the ground lug to the CT lug and then down the pole to the ground electrode under the pole.
3 leads from the secondary to the secondary lines.
At the end of that circuit the primary/secondary netural continues on to the next transformer.
Also at the tap for the cutout there is what appears to be an arc gap arrestor connected to between the primary and ground wire.
Those transformers with 2 primary side connections are wired the same, except the 2nd connection goes to the ground wire, which is also connected to the neutral at the secondary CT. There is no simple single ground/neutral bonding point like there is in a panel.
As I was walking the poles I came to the one place where one circuit ended and another started. The pole happened to be on a corner and had the 3 secondary from one circuit land on one side of the pole and feed one house. The other other circuit land 90 degrees from the first and feed another house. Then there was a single jumper from neutral on one circuit to that of the other.
Note - this is for all above ground distribution I am sure that under ground is handled differently.