When is it not allowed to adjust the tap changer of the transformer on load voltage regulating device?

1. During overload operation of transformer (except for special cases)

2. The light gas protection of the on load voltage regulating device of the transformer frequently presents signals.

3. When there is no oil in the oil pointer of the on load voltage regulating device of the transformer.

4. The number of voltage regulation exceeds the specified value.

5. When the pressure regulating device is abnormal.

When is it not allowed to adjust the tap changer of the transformer on load voltage regulating device?-SPL- power transformer, distribution transformer, oil immersed transformer, dry type transformer, cast coil transformer, ground mounted transformer, resin insulated transformer, oil cooled transformer, substation transformer, switchgear