摘要 |
The dangers inherent in the failure of available sensors to protect against explosions of the tanks of oil filled transformers has been found to be due in part to failures of such sensors to compensate for the fact that the temperature-pressure relationship in tanks of oil filled transformers does not necessarily follow a single valued constant volume version of Boyle's Law. The construction of the apparatus is readily adaptable to pressure only or temperature only sensing, to contact make or break operation either inside or outside of the tank. Further difficulties arise particularly in stiff systems from failure of available protective systems to respond in a manner to prevent explosions in spite of a warning that conditions have reached the danger point. These dangers are further overcome by the use of a sensor which senses both temperture and pressure in the system to short circuit the high-voltage input conductor to the transformer to ground whereby a current limiting fuse or other overcurrent device is quickly opened thus causing the protective device immediately ahead of the transformer to clear the fault and prevent explosion of the transformer.
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