MR VACUTAP - Bleeding On-Load Tap-Changer Head and Suction Pipe

4 Commissioning
Maschinenfabrik Reinhausen GmbH 2020 315788897/03 EN VACUTAP
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VVS
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2. Establish a connecting lead between pipe connection E2 and one of the
pipe connections R, S or Q to ensure equal pressure in the oil compart-
ment and transformer during evacuation.
Figure16: Connecting lead
3. Fill on-load tap-changer with new mineral insulating oil for transformers in
accordance with IEC 60296 using one of the two free pipe connections of
the on-load tap-changer head.
Figure17: Pipe connections S and R
4. Take oil sample from oil compartment.
5. Record temperature of oil sample just after sample is taken.
6. Determine dielectric strength and water content at a diverter switch oil
temperature of 20 °C ± 5 °C. The dielectric strength and water content
must comply with the limit values provided in the appendix.
7. Bleed the on-load tap-changer.
8. Perform trial tap-change operations.
4.1.2 Bleeding on-load tap-changer head and suction pipe
4.1.2.1 Bleeding on-load tap-changer head
1. Open all forward and return valves in the pipe system.