01-08-2025
Recommendations for the Use of Capacitors from BTB Electric
Reactive Power Compensation Capacitors play a crucial role in improving power factor, reducing energy losses, and enhancing the operational efficiency of the electrical system. The installation of these capacitors not only helps save electricity costs but also contributes to stabilizing the voltage for equipment within the system. However, capacitors are highly sensitive to factors such as poor power quality (harmonics, voltage fluctuations) and unfavorable environmental conditions, especially high temperatures, which can reduce efficiency and shorten the lifespan of the equipment. Therefore, during the selection, installation, and operation of capacitors, the following points should be considered:
Allowable Operating Temperature for Capacitors:
- The allowable operating ambient temperature for the capacitor is from -25°C to +55°C, with the average daily temperature not exceeding +35°C. It is recommended to install an automatic cooling fan to prevent the capacitor from overheating.
- The maximum allowable temperature at the discharge resistor location should not exceed +125°C.
- Based on results from both internal and external typical testing, under ambient conditions of +55°C, the maximum temperature at the hottest point on the capacitor body can reach approximately +70°C. In such cases, we recommend regular monitoring and the installation of a thermal relay to automatically disconnect the power when the capacitor exceeds the specified temperature limit.
Recommended Distance and Installation Method to Ensure Optimal Operating Temperature for Capacitors:
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Pressure Activation Mechanism in Case of Excessive Pressure in Capacitors:
Our capacitors are dry-type, designed with a self-protection mechanism to handle abnormal operating conditions such as overvoltage, overcurrent, or excessive temperature. In such cases, the MPP (metallized polypropylene) capacitor has the ability to self-recover while generating gas inside the capacitor shell. When the gas accumulation reaches a certain level due to these abnormal conditions, the internal pressure protection mechanism is activated, causing an internal disconnection and isolating the capacitor from the electrical system, ensuring the safety of the entire system.
Survey of Power Quality Before Installing Capacitors in an Operating System:
- Before installing the capacitors, it is necessary to conduct a power quality survey at the intended installation site, under conditions where no capacitors are in operation, to ensure accurate measurement results.
- If the total voltage harmonic distortion (THDu) is ≥ 3%, it is recommended to install the capacitor in combination with a reactor to prevent resonance and protect the capacitor.
- Similarly, if the total current harmonic distortion (THDi) is ≥ 12%, combining the capacitor with a reactor is essential to ensure the capacitor’s lifespan and safe operation.
The above are our technical recommendations to ensure that the capacitor operates safely, stably, and efficiently within the electrical system.
