Contents
1. Introduction
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1.1 General
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1.2 Repair categories
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1.3 Serial number
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1.4 Spare parts list
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1.5 Maintenance guide
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1.6 Tightening torque
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2. Trouble-shooting
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2.1 On-load tap-changer
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2.2 Pressure relay
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2.3 Motor-drive mechanism
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2.3.1 Control system
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2.3.2 Power system
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2.3.3 Miscellaneous
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3. Repairs and adjustments
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3.1 Replacement of gear box on the on-load tap-changer or
replacement of o-rings for the gear box ________________________________
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3.1.1 General
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3.1.2 Tools required
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3.1.3 Material and spare parts required
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3.1.4 Procedure
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3.2 Replacement of diverter switch housing cover gasket
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3.2.1 General
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3.2.2 Tools required
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3.2.3 Material and spare parts required
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3.2.4 Procedure
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3.3 Restoring the gas cushion
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3.3.1 General
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3.3.2 Equipment required
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3.3.3 Procedure
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3.4 Replacement or addition of a multi-position switch (BUL only)
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3.4.1 General
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3.4.2 Tools Required
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3.4.3 Procedure
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3.5 Examination of the diverter switch after a pressure relay trip
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3.5.1 Tools and material required
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3.5.2 Procedure
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3.6 Tests of the pressure relay
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3.7 Replacement of pressure relay
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3.7.1 General
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3.7.2 Tools required
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3.7.3 Spare parts required
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3.7.4 Procedure
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