B, casing oil level should be normal, no damage cracks outside the casing, no serious oil pollution, no discharge marks and other abnormal phenomena.
C, transformer sound is normal.
D, cooler handle temperature should be similar, fan, oil pump, water pump work normally, oil flow relay work normally.
E, moisture absorber in good condition, absorbent dry.
F, lead joint, cable, bus should be no heating phenomenon.
G, pressure relief device, safety airway and explosion-proof membrane should be intact.
H there is no gas in the gas relay, the radiator and the gas relay are connected by the transformer body, and the valve is in the open position.
Extended data
Transformer is an electrostatic appliance made by electromagnetic induction principle. When the primary coil of transformer is connected to AC power supply, alternating magnetic flux is generated in the iron core, which is generally expressed by φ.
In order to reduce eddy current and hysteresis loss in iron, the iron core is made of painted silicon steel sheets. There is no electrical connection between the two coils, which are made of insulated copper wire (or aluminum wire). One coil connected to an AC power supply is called a primary coil, and the other coil connected to an electrical appliance is called a secondary coil.
The actual transformer is very complicated, and there are inevitably copper loss (coil resistance heating), iron loss (iron core heating) and magnetic leakage (air-closed magnetic induction wire). In order to simplify the discussion, only the ideal transformer is introduced here.
The conditions for the establishment of an ideal transformer are: ignoring leakage flux, ignoring primary and secondary winding resistance, ignoring core loss, and ignoring no-load current (the current in the primary winding when the secondary winding is open).
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