Harmony™ Series Transformers

    Harmony™ Series Transformers

    HARMONY™ SERIES isolation transformers and autotransformers combine very low zero sequence impedance outputs with phase shifting for effective harmonic mitigation. They are designed to replace standard or k-rated transformers, especially when servicing single phase (120V L-N) non-linear loads, such as personal computers and other power electronic equipment.


    NEMA STD TP1 Compliant Harmonic Mitigating Isolation Transformers with low zero sequence impedance secondary windings. Available with either 0° or 30° phase shift between primary and secondary windings.

    Configuration of the secondary windings cancels the fluxes generated by the triplen harmonics in the load current thereby minimizing triplen harmonic voltage distortion. Choice of phase shift permits cancelling of 5th and 7th current harmonics against those of other loads fed from the same primary supply.

    Harmony-2E™ and Harmony-3E™

    NEMA STD TP1 Compliant Multiple output phase shifting transformers with extremely low zero sequence impedance (patented). Available in both isolation or autotransformer configurations.

    All models have secondary windings which cancel the triplen harmonic fluxes to minimize triplen harmonic voltage distortion. 5th, 7th and other higher order harmonics are cancelled as well to further reduce heating, voltage distortion, and upstream harmonic currents.

    Harmonics treated by the secondary windings are as follows:

    Harmonic No. Product
    3rd, 5th, 7th, 9th, 15th, 17th Harmony-2™*
    3rd, 5th, 7th, 9th, 11th, 13th Harmony-2™
    * pairs of Harmony-2™ transformers can be configured to treat 11th & 13th on the primary bus.

    The impedance of standard or K-factor transformers will often introduce anywhere from 5-15% voltage distortion when servicing non-linear loads. Multiple output Harmony™ transformers will typically add only 1-3% voltage distortion when servicing similar non-linear loads.