Dry type transformer temperature monitorr BWDK-326

Real-time Monitoring

Continuous winding temperature detection with PT100 sensor

Overheating Protection

Automatic alarm and trip control for transformer safety

Automatic Cooling

Smart fan control for forced air cooling operation

Fault Detection

Built-in diagnostic for early failure prevention

Q1: Why is transformer temperature monitoring important?

Temperature monitoring is critical for preventing transformer failure and extending equipment lifespan. Excessive heat in windings can cause insulation breakdown, reduced efficiency, and catastrophic failure. A temperature controller detects hot spots early, activates cooling systems, and provides protection through alarms and automatic shutdowns, significantly reducing maintenance costs and downtime.

Q2: What causes transformer overheating and hot spots?

Common causes of transformer overheating include:

• Overloading beyond rated capacity
• Poor ventilation and inadequate cooling
• Ambient temperature exceeding design limits
• Harmonic distortion in electrical system
• Insulation degradation or contamination
• Cooling fan failure or malfunction

Q3: How does the PT100 temperature sensor work?

PT100 is a platinum resistance temperature detector (RTD) that changes electrical resistance proportionally to temperature. “PT” stands for platinum, and “100” indicates 100 ohms resistance at 0°C. The sensor is embedded directly in transformer windings to measure actual hot spot temperature with high accuracy (±0.1°C). Platinum ensures excellent stability, repeatability, and long-term reliability in harsh electrical environments.

Q4: What is the difference between alarm and trip functions?

Alarm Function: Activates at a preset temperature threshold (typically 130-150°C) to warn operators of elevated temperature. The transformer continues operating while cooling system engages. Allows time for corrective action.

Trip Function: Activates at a higher critical temperature (typically 155-170°C) to automatically disconnect the transformer from the power supply, preventing damage or fire. This is an emergency shutdown protection.

Q5: Can this controller integrate with existing SCADA or BMS systems?

Yes. Model BWDK-326E provides 4-20mA analog output for standard industrial control systems. Model BWDK-326F offers RS485/RS232 serial communication using Modbus protocol. Model BWDK-326EF combines both features for maximum flexibility. These communication options enable remote monitoring, data logging, and integration with building management systems (BMS) or supervisory control and data acquisition (SCADA) platforms.

Q6: How often should the cooling fan exerciser function be used?

The built-in fan exerciser automatically runs cooling fans periodically (typically once per week for 1-2 minutes) even when temperature is low. This prevents bearing seizure and lubricant degradation during long periods of inactivity, ensuring fans are ready when needed. The exerciser function significantly extends fan service life and improves reliability in emergency cooling situations.

Q7: What maintenance is required for the temperature monitoring system?

Minimal maintenance is required:

• Monthly: Check display readings and verify fan operation
• Quarterly: Clean controller housing and verify alarm/trip settings
• Annually: Test sensor accuracy and perform system calibration
• As needed: Verify sensor cable connections and inspect for damage

The self-diagnostic function continuously monitors system health and alerts operators to sensor faults or connection issues.

Q8: What happens if a temperature sensor fails?

The automatic fault detection function continuously monitors all PT100 sensors for open circuits, short circuits, or out-of-range readings. When a sensor fault is detected, the controller displays a fault code, activates a warning indicator, and can trigger an alarm output. The system continues monitoring remaining sensors to maintain protection. Historical data helps diagnose intermittent failures.