An oil temperature indicator is a device used to measure the temperature of the oil in a transformer. The oil in a transformer serves several vital functions, including providing insulation for the electrical components, cooling the transformer, and protecting the transformer from external contaminants. The oil temperature in a transformer can significantly impact its performance and lifespan. If the oil becomes too hot, it can reduce the insulation properties of the oil and lead to electrical failure or damage to the transformer. On the other hand, if the oil becomes too cold, it may not be able to effectively cool the transformer, which can also lead to problems.
The oil temperature indicator typically consists of a temperature sensor, such as a thermocouple or a resistance temperature detector, and a display or indicator that shows the temperature of the oil in real time. The temperature sensor is usually installed in the transformer oil tank or a separate oil sample compartment. An oil temperature indicator is an essential tool for monitoring the health and performance of a transformer. By regularly checking the oil temperature, operators can identify potential problems with the transformer and take appropriate action to prevent damage or failure. This device measures the top oil temperature by putting a sensing bulb in a pocket and letting liquid in the bulb expand through a capillary connection to an operating mechanism. This movement is amplified by a link and lever system that moves the disc that holds the pointer and mercury switches. When the amount of liquid in the mechanism that does the work changes, the bellow at the end of the capillary tube expands and contracts. Through a linkage of levers, this movement of the bellow is sent to the pointer on the temperature indicator of the transformer.
The marshalling box has an oil temperature indicator used to determine the temperatures of the top oil in the transformer. The maximum oil temperature of an oil-immersed power transformer is measured by a system based on the volume of a liquid growing as its temperature increases. The measuring system comprises a sensing bulb, a measuring bellow, and a short barrel capillary that links the two. Complete air temperature compensation on the sensing bulb and line getting compensated below and a vein that ends at the head of the sensing bulb. The liquid inside this reacts to changes in the temperature around it. The measurement system and trying to compensate bellows are connected, so their effects cancel each other out.
The (OTI)oil temperature indicator is made up of a sensor bulb, a capacity tube, and a dial thermometer. The sensor bulb is positioned in the area of the engine that contains the oil that is at its hottest. Evaporation liquid has been placed within both the sensor bulb and the capacity tube. The variations in the vapour pressure that occur as a result of the temperature are communicated to a bourdon tube that is housed within the dial thermometer. This tube moves in a manner that is proportional to the changes in pressure that occur as a result of the temperature. In OTI, there are two different types of mercury switches, which are denoted by the letters S1 and S2. The switch labeled S1 is utilized for the Alarm, whereas the switch labeled S2 is used for the Trip.
The dial of the oil temperature indicator also has a dummy pointer that is moved by the main lead when the temperature goes up. When the primary information moves back because the temperature is going down, the dummy pointer stays where the main arrow is at the highest temperature. This shows how much the transformer’s temperature can rise in a set amount of time.