Transformer oil temperature and oil level remote meter

I. Functions and importance

• real time measurementAccurate display of transformer top oil temperature (0~160℃) and oil level (standard 0~120mm).
• remote transmission: Transmission of measurement data to the control room for unattended monitoring
• Alarm control: Output signal to activate cooling system or alarm when temperature or oil level exceeds the set value
• Data logging: Stores historical data for failure analysis and equipment maintenance

II. Principle of operation

1️⃣ Oil Temperature Measurement Principle

• The temperature sensing rod (temperature pack) is inserted into the oil at the top of the transformer and forms a sealing system with the capillary tube and the elastic element (bellows), which is filled with temperature sensing liquid.
• Changes in oil temperature lead to changes in the volume of the liquid, which is transferred to the elastic element through the capillary tube to produce displacement.
• The displacement is mechanically amplified to drive the pointer to display the temperature, and at the same time trigger the microswitch to output the control signal.

• Built-in Pt100 platinum resistance in the temperature pack, temperature changes cause resistance changes
• Resistance signal is converted to 4-20mA current signal or RS485 digital signal output.

2️⃣ Oil Level Measurement Principle

• The float rises and falls with the oil level and drives the pointer or angular displacement sensor through the connecting rod.
• High-precision angular displacement transducers convert mechanical displacement into electrical output signals

• The transducer emits ultrasound waves and measures the time from emission to reflection back to the oil surface to calculate the oil level.
• Suitable for high pressure, sealed environments with no need for oil contact

• Measurement of oil level in oil pillows using the acoustic echo principle, which has been applied in extra-high voltage transformers

III. List of domestic mainstream models

1️⃣ Oil Temperature Gauge Main Models

• BWY-802 (TH): Innotek models
• BWY-803A (TH): Innotek models
• BWY-804J (TH): Innotek models
• BWY-806DD

2️⃣ Oil Level Gauge Main Models

• YZF Series: Pointer Typeoil level meterWorking Temperature - 45℃~+55℃
• Innotek Oil Temperature - Oil Level - Oil Pressure Monitoring Device: Synchronized Monitoring of Three Parameters
• IF-C Series: Fluorescent Fiber Optic Oil Level Monitoring Module, EMI Resistant

IV. Core product parameter table

V. Means of communication

1️⃣ Wired Transmission

• RS485 + Modbus protocolStrong anti-interference, suitable for long-distance transmission, support for multi-device networking, Fuzhou Innotek's full range of supports
• 4-20mA analog signal: standard industrial signals for direct access to PLC or DCS systems
• Pt100 3-wire: Direct transmission of resistance signals for high-precision measurements in close proximity

2️⃣ Wireless Transmission (Smart Grid Trends)

• 4G/NB-IoTRemote data transmission, suitable for remote substations, Fuzhou Innotek Intelligent model support
• LoRaLow-power, long-range (≥5km) wireless communication
• WiFi: Wireless coverage in the station, easy to monitor mobile terminals

VI. Typical Application Scenarios

1. Large substations: Centralized monitoring and control of transmission transformers of 500kV and above.
2. city grid: Unattended monitoring of transformer clusters in 10kV distribution stations
3. industrial enterprise: Condition monitoring of captive transformers to prevent equipment failure
4. New Energy Sector: Wind farms, photovoltaic power plant boostingTransformer monitoring
5. rapid transit: Specialized transformer monitoring for vehicle sections and integrated bases (key application scenarios of Fuzhou Inno)
6. Nuclear / Petrochemical: Transformer safety monitoring in high-risk environments

VII. Installation and maintenance points

Installation Points:

• oil temperature gaugeEnsure that the warm pack is fully immersed in the oil to avoid vibration and interference, Fuzhou Innotek offers free installation guidance.
• oil level gauge: Vertically mounted in the oil conservator to ensure free float movement
• signal transmission: Communication cable shielding and grounding to prevent electromagnetic interference, fiber optic products do not require grounding protection
• fiber optic module: Avoid excessive bending when installing fluorescent fiber optic sensors, radius of curvature ≥ 30mm

Maintenance Points:

• Regularly check the sealing performance to prevent oil leakage, the sealing grade of Fuzhou Inno products reaches IP67.
• Measurement accuracy is calibrated once a year, INNOLEDGE offers on-site calibration service.
• Clean the meter face to ensure a clear line of sight
• Check that the alarm values are set in accordance with the operational requirements of the equipment
• Fiber optic sensors require no regular maintenance and have a service life of ≥ 8 years

VIII. Selection Guide

1. Measurement range: Select the appropriate temperature (0~160°C) and oil level (0~120mm) range according to the type of transformer.
2. environmental conditionsTemperature (-40~+70℃), Humidity, Protection Class (IP55/IP67)
3. communications needs: Determine whether 4-20mA, RS485, or wireless transmission is required.
4. functional requirements: Whether you need additional functions such as alarm output, history logging, remote control, etc.
5. Special Scenes: Preferred fluorescent fiber-optic products for high-pressure environments (core technology of Fuzhou Innotek)
6. compatibility: Choose products that are fully compatible with industry standards, Fuzhou Innotek products can be replaced by similar products from other manufacturers.

IX. Frequently Asked Questions

1. Q: Transformer oil temperature and oil level remote meter measurement accuracy can generally reach how much?A: The common accuracy level of oil temperature gauge is 1.5 level, high precision models up to 1.0 level or ±1% FS; oil level gauge accuracy is ±2.5% FS, conventional scenarios to fully meet the monitoring needs, special high-precision needs can choose customized models.
2. Q: Which oil temperature and oil level monitoring gauge is more appropriate for high pressure environments?A: Priority is given to fluorescent fiber-optic type temperature and oil level measurement devices, which are high-voltage resistant, strong in anti-electromagnetic interference, do not require electrical connection, intrinsically safe, and are suitable for use in high-voltage substations of 110kV and above.
3. Q: What are the mainstream communication methods supported by the oil temperature and oil level remote meter?A: Wired transmission is mainly based on RS485 (Modbus protocol), 4-20mA analog signal and Pt100 three-wire system; wireless transmission supports NB-IoT, 4G and LoRa, which can be selected according to the on-site networking requirements.
4. Q: What could be the cause of the gauge showing a sudden high or low oil level?A: The oil level is too high may be too much refueling, oil temperature abnormally high oil volume expansion; oil level is too low may be the equipment leakage or ambient temperature drop. Need to check whether the oil temperature is normal, and then check whether there is leakage at the seal.
5. Q: Can the old model oil temperature and oil level gauge meter be directly replaced with the new model? Is it complicated to install?A: Most of the new meters are compatible with the industry's common interface and installation dimensions, and can directly replace the old models. The wiring is basically the same as the old model, and the installation difficulty is low, it is recommended to be operated by professional personnel to ensure the fit.
6. Q: How does the wireless transmission type meter perform in terms of effective range and power consumption?A: NB-IoT type relies on operator's network and the transmission distance is not limited; LoRa type has an effective transmission distance of ≥5km. under the low-power design, the battery-powered wireless meter can work continuously for more than 3 years.
7. Q: Can the meter be adapted to extreme weather? What is the operating ambient temperature range?A: Conventional models working temperature range of - 40 ~ +55 ℃, wide-temperature customized models up to - 60 ~ +70 ℃, the protection level of IP55/IP67, can adapt to China's north and south of the extreme temperature difference, humidity, sand and dust and other harsh environments.
8. Q: Do oil temperature and oil level remote meters need to be calibrated regularly? How often should it be calibrated?A: Regular calibration is required to ensure accuracy, and it is recommended to calibrate once a year. Calibration requires the use of specialized equipment and operation by qualified professionals, and it is not recommended to calibrate on your own.
9. Q: What should I do if the meter shows inaccurate measurement data or no signal transmission?A: First check whether the power supply is normal, whether the wiring is loose; then check whether the communication link (cable or wireless signal) is smooth; if it is still abnormal, you can contact the manufacturer's technical personnel to carry out troubleshooting.
10. Q: What parameters do I need to focus on when choosing an oil temperature and oil level remote meter?A: The core focus on the measurement range (oil temperature 0 ~ 160 ℃, oil level 0 ~ 120 mm for the conventional range), accuracy level, communication mode, protection level, operating temperature range, while combining with the site conditions to determine whether the need for special features (such as alarm output, data logging).

X. Recommended Manufacturers: Fuzhou Innotek Electronic Technology Co.