GB1005622A - Instrument for determining the temperature of a transformer winding in operation - Google Patents

Abstract

1,005,622. Temperature measurement. ARIC Ltd. June 30,1964 [July 17,1963], No. 28348/63. Heading G1D. An instrument for determining the temperature of a transformer winding comprises a fluidfilled bulb 10 disposed in the cooling oil of the transformer and connected to a bellows 16 by way of a junction piece 12, the bellows 16 being arranged to move a pointer 21 or operate a recording instrument, and a heater 25 energized in dependence of the electrical load on the transformer by way of a small transformer 26, the heater heating a further bulb 27 also connected to the junction piece 12 to produce additional movement of the pointer 21 or recording instrument to simulate the temperature at the hottest point in the transformer. Compensation for changes in ambient temperature are made by the provision of an unheated bulb 36 connected to a bellows 30, the bellows 30 acting on the bellows 16 by way of interengaged toothed quadrants 34, 35. A pipe 39 leading to a point adjacent the bulb 10-compensates for changes due to the pipe 11 connecting the bulb 10 and junction-piece 12. In attenative constructions the heated bulb 27 may be connected to a separate bellows whose action is additive to that of the bellows 16, or the heater 25 may be placed adjacent a fluid filled bellows or bimetal strip which is arranged to displace an abutment of the bellows 16 or a point in the linkage between the bellows and the pointer. This a bimetal strip may be arranged to displace the anchorage point 31 of the bellows 30. The expansible material within the bellows and bulbs may be a liquid or a vapour.