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Explain the K-Factor rating?

K factor is defined as a ratio between the additional losses due to harmonics and the eddy current losses at 60Hz. It is used to specify transformers for non-linear loads. Transformers with a rated K factor of 4, 9, 13, 20 are available. For balanced loading, a transformer with a K factor of 4 should be specified when no more than 50% of the total load is non-linear. A transformer with K factor 9 should be specified when 100% of the load is non-linear. For critical applications, K=13 can be considered.

As the K-factor of the transformer increases, generally the size and cost increase, low load efficiency (<25% load) decreases and impedance decreases. That is the trade-off to be able to handle higher harmonic factors.

Learn more about HPS Sentinel K

Learn more about HPS Sentinel H

  • Explain the K-Factor rating?

      K factor is defined as a ratio between the additional losses due to harmonics and the eddy current losses at 60Hz. It is used to specify transformers for non-linear loads. Transformers with a rated K factor of 4, 9, 13, 20 are available. For balanced loading, a transformer with a K factor of 4 should be specified when no more than 50% of the total load is non-linear. A transformer with K factor 9 should be specified when 100% of the load is non-linear. For critical applications, K=13 can be considered.

      As the K-factor of the transformer increases, generally the size and cost increase, low load efficiency (<25% load) decreases and impedance decreases. That is the trade-off to be able to handle higher harmonic factors.

      Learn more about HPS Sentinel K

      Learn more about HPS Sentinel H

  • What are K-Factor Transformers and where are they used?

      K-factor transformers are designed to withstand the extra heating and higher neutral currents caused by harmonics created by non-linear loads such as VFD, DC power supplies and LED lighting. K-factor distribution transformers in North America are subject to minimum efficiency regulations in both the U.S.A. and Canada. K-Rated transformers must have:

      • Operate at specific K-rated harmonics without overheating
      • 200% rated neutral
      • Electrostatic Shield

  • What is the energy efficiency regulation compliance in the U.S. and Canada?

      In the past several years, there has been an accelerated rate of change in updating energy efficiency standards for transformers in North America.

      Governments in US and Canada are encouraging users to use higher energy efficiency dry-type transformers, to help reduce carbon dioxide emissions. There is also a long term cost savings in operating higher efficiency transformers translated in lower energy usage, lower cooling cost, etc.

      In U.S.A. the Department of Energy (DOE) has mandated new higher efficiency levels effective Jan. 1st 2016.

      In Canada Natural Resources Canada (NRCan) published SOR/2016-311 which amends the Energy Efficiency Act to align the via amendment 14 the minimum energy efficiency levels for dry type transformers to the ones implemented by DOE in Jan 2016.

      The new NRCan 2019 regulation is going to be enforced across Canada on May 1st, 2019. The Ontario government already adopted these new efficiency levels by publishing the ON Reg.404-12 which in schedule 6 defines the new energy efficiency levels that dry type transformers sold in ON must comply with starting Jan.1st 2018 (Ontario Energy Efficiency Compliance).

      The rest of Canada (including Quebec) is still following the current energy efficiency levels prescribed by CSA C802.2, until the new NRCan regulations come in effect on May 1st 2019.

      To help our valued customers in estimating the cost savings resulting from upgrading their old dry type transformer to the new DOE2016/NRCan2019 efficiency levels, HPS has developed an Energy Savings Calculator available on its website. To find out how HPS can help reduce your energy consumption, click here.

      To visit the Canadian Gazette for more information about the Canadian energy efficiency standards, click here.

      For the Ontario Energy efficiency regulation please click here.

      To view an electronic copy of the U.S. DOE energy efficient standards, click here.