The Blue Jay TWSK Series is an analog transformer temperature controller specifically designed for container transformer stations. It continuously monitors transformer oil temperature and ambient environmental temperature, and automatically controls cooling fans, heaters, alarm relays, and trip actions based on measured values and user‑programmed thresholds. An armored PT100 liquid sensor with three‑wire connection is used for the oil temperature measurement, supporting cable runs of up to 20 meters without requiring compensation or calibration. An RS‑485 interface with Modbus RTU protocol enables remote monitoring and data transmission.

Automatic Protection and Environmental Adaptation

• Fans, Alarm, and Trip: Three independent relay outputs (rated 5 A at 250 V AC) provide an integrated control sequence—fans are activated at elevated ambient temperature, an over‑temperature alarm is triggered when the oil temperature exceeds a predefined threshold, and a trip relay disconnects the transformer if the oil temperature reaches a critical limit, providing a layered protection strategy in a single controller.
• Heater Control for Dehumidification: When ambient humidity approaches condensation levels, the controller automatically activates an external heater to prevent moisture accumulation that could degrade transformer insulation.
• Wide Operating Range: The controller itself is designed to operate reliably from -40 °C to 80 °C, making it suitable for outdoor container transformer stations exposed to extreme climates.

Measurement Accuracy and Analog Output

• Armored PT100 Sensor: The armored PT100 resistance temperature detector provides high‑precision temperature readings of the transformer oil with an accuracy better than 1 °C, while the humidity measurement accuracy is better than 5 %.
• Dual DC 4‑20 mA Outputs: Two independent analog outputs transmit temperature and humidity values to remote SCADA systems, chart recorders, or distributed control systems for integration into plant‑wide monitoring architectures.
• 3‑Digit LED Display: The programmable switching display shows real‑time collected data, enabling on‑site operators to verify measurements without additional instruments. Parameters can be configured directly by the user through the front panel.

Applications

• Container‑type substation transformer winding and oil temperature monitoring
• Dry‑type and cast resin transformer thermal protection for industrial and utility installations
• Transformers in mining, oil & gas, solar, and wind energy applications requiring remote temperature surveillance
• Retrofit projects replacing outdated bimetallic temperature switches with a single unit capable of fan control, alarm, trip, analog retransmission, and Modbus communication