1. is the place that transformer was located fixed or movable? substation

2. the cables are connected and the tank or casing is earthed before or after the transformer is put into its permanent position? After

3. a sample of oil in a transformer is tested for what purpose? the oil must be taken for chemical tests or voltage breakdown test

4.the transformer should be inspected visually for oil level with or without de-energizing?yes

5.when must the transformer immediately be disconnected from the supply? If it discovered the oil level is low, an oil leak exists, compound leak from a box, or the transformer hums abnormally.

6. when the transformer carries a constant load what is a sign of a leak in the tank? the windings have become over heated because of an overload or an internal fault within the transformer

7. if an overload or an internal fault happened within the transformer how is the level of oil? Rise

8. what may lead to compound leakage from the cable box? a poor contact at the terminals of cable conductors

9.when should the transformer be disconnected from the supply? when scheduled maintenance is done

10. what is the shortest scheduled maintenance of transformer? At least once every six months a sample of the oil should be taken from the transformer for dielectric strength ( breakdown voltage) test. Not less than once in 12 months sludge and acidity tests should be performed.