| # | Label | Description | Cable/pipe diameter | Tool size | Tightening torque |
|---|---|---|---|---|---|
| 1 | Oil Out | Oil return to transformer. | 10 mm (0.39 in) | 19 mm | - |
| 2 | Oil In | Oil intake from transformer. | 10 mm (0.39 in) | 19 mm | - |
| 3 |  |
Ground connection. | 1.5–50 mm2 (16–1/0 AWG) conductor | 5 mm | 3.5 Nm (1.5–10 mm2)10 Nm (15–50 mm2) |
| 4 | RS-485 | RS-485 connection. | 5–10 mm (0.20–0.39 in) | 20 mm | 5 Nm |
| 5 | Relay control out | Relay control to OPTPSU. Use Vaisala cable CBL210539. | 7–12 mm (0.28–0.47 in) | 24 mm | 10 Nm |
| 6 | DC in | DC input from OPTPSU. Use Vaisala cable CBL210544. | 9–16 mm (0.35–0.63 in) | 30 mm | 12 Nm |
| 7 | Ethernet | Ethernet connection. Use shielded outdoor Ethernet cable. Assemble the included protection shell on the RJ45 connector. | - | - | - |
| 8 | Spare | Not reserved. | 5–10 mm (0.20–0.39 in) | 20 mm | 5 Nm |
| 9 | Spare | Not reserved. | 7–12 mm (0.28–0.47 in) | 24 mm | 10 Nm |