Equipment and appliances requiring reactive energy

All AC equipment and appliances that include electromagnetic devices, or depend on magnetically coupled windings, require some degree of reactive current to create magnetic flux.

The most common items in this class are transformers, reactors, motors and discharge lamps with magnetic ballasts (see Fig. L6).

The proportion of reactive power (kvar) with respect to active power (kW) when a piece of equipment is fully loaded varies according to the item concerned being:

• 65-75% for asynchronous motors (corresponding to a Power Factor 0.8 – 0.85)
• 5-10% for transformers (corresponding to a Power Factor close to 0.995)

Fig. L6 – Power consuming items that also require reactive energy