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AIR-CELL OIL STORAGE UNIT "ATMOSEAL" TYPE |
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GENERAL
The air-cell storage unit maintains a constant pressure (atmospheric pressure) on the insulating oil and preserves it from coming into contact with the atmosphere and thus forming humidity and oxidation. |
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| The system achieves a small head of oil with an expansion chamber set above the transformer cover so that it is always full. A duct goes from the expansion chamber to the transformer caisson; this duct contains the gas relay. This device therefore permits the expansion and contraction of the oil as the temperature varies, but there is no active circulation between the two containers. The expansion chamber lodges an air-cell made of a special, oil-resistant rubber that is kept inflated by the atmospheric pressure that is transmitted through a breather duct that freely connects the air-cell to the external environment. When the system is started in the way described, the air-cell keeps an air seal at atmospheric pressure i.e. it is inflated and deflated as the oil volume in the expansion chamber varies. This type of storage unit normally requires no maintenance. (look picture 1 valid only for explanatory purposes). | |
| Picture 1 | |
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