Procedure - ABB UCC Series Installation And Commissioning Manual

6.5.1 Procedure

1. Close the valve in the tube to the conservator.
2. Connect the oil pump to the oil valve. (For connection dimensions, see the
dimension drawing for the on-load tap-changer), see Figs. 45 and 47.
3. Open the oil valve and the air release valve.
4. Start the oil pump and drain approximately 45 litres of oil into a clean and dry
container.
5. Close the air release valve.
6. Close the oil valve and disconnect the pump.
7. Connect the output side of the pump to the oil valve.
8. Open the oil valve.
9. Open the valve in the tube to the conservator!
10. Pump the earlier drained 45 litres of oil back into the diverter switch housing.
11. Close the oil valve and disconnect the pump.
12. The level in the oil conservator and the gas cushion are now restored.
Oil valve
CAUTION
Open
6 Oil Filling
Open end wrench
key width 6 mm
Air release valve
TC_00154