“They are typically tuned to specific harmonic orders – 3rd, 5th, 7th and 11th, for example – providing low-impedance paths at those frequencies to divert harmonic content,” according to the company, which is aiming at “maintaining THID in compliance with the current and voltage requirements of IEEE 519”. “Capacitive elements in these filters offer reactive power compensation, enhancing the system’s power factor,” it added. The family is called TPQH3411, and at a nominal 400V, its members range from a 1kW 3A load version weighing 9kg, to a 250kW version at 330kg. In size, the range is 360 x 160mm by 220mm tall, to 1.4m x 550mm x 600mm tall. 1.6x over-load is possible for one minute once per hour, and efficiency is >98% at rated voltage and power.