Hello, everyone. I was browsing some old 1950s street photographs of the Cincinnati suburb of my youth and was curious about the medium voltage (MV) lines seen on the utility pole cross arms. Unlike most of the present day 3-phase MV runs in the U.S. with 3 wires on a crossarm and the neutral carried lower on the pole, the photos show poles each having a top cross arm with 4 wires and a lower cross arm with 2 wires. Below them are what look to be 120/240 LV wires. None of the old photos clearly show the connections for a pole-mounted MV-LV distribution transformer. So for anyone with an historical knowledge of these methods your comment is greatly appreciated. Sincerely,
1950s MV Distribution
Aug 15, 2016
3 Replies
I will have to look at some of the pictures from my youth (early 50s) and see what is there. I think there were just 3 MV wires on the pole tho. I do remember a fun game was throwing a straightened coat hanger up into the primary, until we blacked out a big section of S.E. DC.
It is probably two circuits on a single pole. I've seen transmission lines (relatively low power, feeding a small substation) that had that arrangement, and it appeared the 3 wires on the left side were one circuit and the three on the right side a second circuit.
Hello, and that was also my first impression. Don't know if a single-phase pole-mounted distro transformer was connected across 2 MV lines or line-to-neutral. Judging from the size of the MV insulators on a pole in the photos, the MV transmission line voltages were most likely considerably lower than what is used in most locales today. Sincerely,
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