With a completely resistive loading, the active power and the apparent power are the same thus the cosφ is 1. Under conditions of inductive loading, the ratio between active power and apparent power will be lower than 1. The lower the cosφ , the higher the absorbed inductive current. Therefore, a plant working with a low cosφ has the following disadvantages: – higher losses of power in transmission in the electrical lines -higher voltage lowerings – higher dimensioning of the generation, transportation, transformation and utilization plants Last but not least, for a low cosφ the companies producing and distributing electrical energy charge – by law- considerable money penalties and sanctions. As a consequence, the energy utilized by the users is lower than that generated by the energy supplier. It is evident that these negative consequences – in a situation of increasing need of energy – are not tolerable in presence of a massive energy saving plan and major performances, both from the point of view of the energy distributor and that of the user. It is therefore important to eliminate or, at least, to reduce the consequences of a low power factor with devices whose behaviour can be compared to a generator of capacitive reactive power as opposed to the phase that is given to the loadings. The capacitors are devices suitable to achieve this purpose.
The single-phase MECO capacitors of the series CMA 1 in metallized polypropylene film are generally created to be assembled with triangle connections for usage in triphase system for power factor correction. The capacitor element is included in an aluminium can which incorporates a pressure sensitive safety device.