Why is it recommended to replace a capacitor when its capacity decays by 20%?
Jun 26, 2025| Q. At what capacitance decay does a capacitor need to be replaced??
A: If the capacity decay exceeds 20%, it is recommended to replace it. If it reaches 50%, it must be replaced because the remaining capacitance is half only, which means the compensation capacity is insufficient.
Q. According to which standard should we replace the capacitor when its capacity has decreased by 20%? IEC standard or the China standard?
A: According to the IEC standard, it requires positive deviation rather than negative deviation. So when the capacity decreases, it is considered as negative deviation.
Q. Assuming the power factor reaches 0.95, if the capacity attenuation exceeds 20% without replace, what impact will it have on the power system? For example, will there be an increase in power consumption or safety hazards, or will the capacitors not be able to meet the demand of reactance?
A: When the capacitor capacity decreases by more than 20%, it has no significant impact on the power system. However, if it continues to be used, it will cause resonance between the capacitor and the reactor, and the workers will not check the capacity every day.