Introduction

In industrial applications, compressors require high power during startup. When a motor starts, it can draw 5–6 times higher current than normal because there is no back EMF initially to oppose the supply.

To control this, soft starter panels are used. These panels reduce inrush current using: 

  • Voltage control (thyristors in modern systems)  
  • Reactor coils (inductors) in series  

The reactor coil provides inductance, which opposes sudden changes in current. As per the principle: 

  • V = L × (di/dt) 

This means when current tries to rise suddenly, the inductor generates an opposing voltage and limits the rate of current increase.  

At the same time, reactor coils generate heat during operation, making temperature monitoring essential. 

Challenges

  • High inrush current leads to heating of reactor coils  

  • Inductors continuously oppose current changes, causing energy loss as heat  

  • Temperature inside the panel can rise to 80°C–200°C depending on load  

  • Overheating can result in:  

    • Coil insulation damage  
    • Reduced equipment life  
    • Risk of failure or shutdown

  • Manual monitoring is not practical for continuous operation  

Solution

The GIC TCS1T100 temperature controller is used to monitor and control panel temperature. 

Working: 
  • Temperature sensor placed near the reactor coil
  • Controller continuously monitors temperature  
  • When temperature exceeds preset value:  
  • Cooling fan is automatically switched ON
  • When temperature reduces:  
  • Fan switches OFF  
Combined Benefit with Reactor Coil: 
  • Reactor coil → Limits inrush current using inductance  
  • TCS1T100 → Controls temperature caused by that inductive operation  
Key Advantages: 
  • Controlled motor starting current  
  • Protection of reactor coils from overheating  
  • Improved reliability of soft starter panel  
  • Reduced maintenance and downtime  

Conclusion

The combination of reactor coils and GIC TCS1T100 ensures both electrical and thermal protection in soft starter panels. 

  • Reactor coils smoothly limit inrush current  
  • Temperature controller prevents overheating  

This results in:

✔ Safer compressor operation
✔ Longer equipment life
✔ Efficient and reliable panel performance