Abstract: Insulating oil in electric power transmission devices such as a transformer is filtered for removal of accumulated water and carbon particles. The filter and circulation pump are usually located in a separate cabinet external to the transformer with circulation conduits connecting the filter, the pump and the transformer. To prevent environmental contamination by leaks or ruptures in the oil circulation conduits, secondary or sleeving conduits surround and protect the circulation conduits and additionally provide an independent leak flow conduit back to the filter cabinet dry sump. An accumulation of oil in the dry sump actuates a fluid sensor to transmit an alarm signal.

Abstract: Insulating oil in electric power transmission switchgear such as a load tap changer for a transformer is filtered for removal of accumulated water and carbon particles. The filter and associated circulation pump is usually located in a separate cabinet external to the switchgear with circulation conduits connecting the filter, the pump and the switchgear reservoir. To prevent or minimize equipment damage that is presaged by excessive insulating oil temperature, oil flow within the oil circulation conduits is monitored for temperature excesses. Alarms are issued and electrical loads are disconnected upon detection of an excess temperature event. If desired, provision may be made for disconnected the jeopardized equipment from its respective service load.

Abstract: Insulating oil in electric power transmission devices such as a transformer is filtered for removal of accumulated water and carbon particles. The filter and circulation pump are usually located in a separate cabinet external to the transformer with circulation conduits connecting the filter, the pump and the transformer. To prevent or minimize environmental contamination by leaks or ruptures in the oil circulation conduits, oil flow within the pump suction conduit is monitored independently of oil pressure within the pump discharge conduit. A flow rate or discharge pressure below a predetermined minimum operates motor control relays to terminate the pump drive motor operation and transmit appropriate alarms. Additionally, an accumulation of oil in the dry sump volume of a pump and filter housing also activates motor terminating relays and transmits an alarm.