| Kita-Iwaki Powerline | |
| Country: | Japan |
| Coordinates: | 35.5906°N 138.7997°W 36.5758°N 139.2236°W 37.4258°N 138.5975°W 37.3814°N 140.8044°W 36.6228°N 138.8017°W 36.7128°N 139.8325°W |
| Start: | Minami-Iwaki switch |
| Finish: | Higashi-Yamanashi substation |
| Operator: | Tokyo Electric Power Corporation |
| Est: | 1999 |
| Length Km: | 240 |
| Ac Voltage: | 500 kV |
| Circuits No: | 2 |
The Kita-Iwaki Powerline is the largest double-circuit powerline for three-phase electric power in the world. Built in 1999, it runs from Minami-Iwaki switch (Tamura, Fukushima) to Higashi-Yamanashi substation (Ōtsuki, Yamanashi) and has 2 circuits, which are operated at present with 500 kV, but can be switched over to 1100 kV if necessary equipment is installed. The conductors of the lines consist of 8*31.5 mm ACSR ropes providing for a total current capacity of 4000 amperes.The line is supported by lattice towers with a typical height of 108 meters. These have three crossbars of spanning 31, 32 and 33 meters.
There are two such lines: the first one is 190 kilometers long and starts at Kashiwazaki-Kariwa Nuclear Power Plant and runs over Nishi-Gunma switch to Higashi-Yamanashi substation. It was built in 1993.The second 240 kilometers long line, which was built in 1999 starts at Nishi-Gunma substation and runs over Higashi-Gunma substation to Minami-Iwaki switch, whereby it passes close to Shin-Imaichi switch, which is not connected to the line.
| Substation/switch | Coordinates | |
|---|---|---|
| Higashi-Yamanashi | 35.5906°N 138.7997°W | |
| Higashi-Gunma | 36.5758°N 139.2236°W | |
| Kashiwazaki-Kariwa | 37.4258°N 138.5975°W | |
| Minami-Iwaki | 37.3814°N 140.8044°W | |
| Nishi-Gunma | 36.6228°N 138.8017°W | |
| Shin-Imaichi | 36.7128°N 139.8325°W |