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Harmonic Analysis Reporting

The Challenge of Harmonics:

The largest challenge with harmonics is not just explaining what it is, but why it’s important to monitor. Analyzing harmonics on board a marine vessel and addressing disturbances is critical for the safety of your electrical systems. Gaining a real understanding of harmonics can be challenging for anyone without an extensive background in the electrical field. Even studied engineers have a hard time grasping the subject. In this post TESS will try to share our knowledge, simply and efficiently, while explaining how a Harmonics Analysis Report can be a cost effective preventative measure for all electrical maintenance programs.

What is a Harmonic?

A harmonic can be defined as “a sinusoidal component of a periodic wave or quantity having a frequency that is an integral multiple of the fundamental frequency.” We know this may be hard to understand. The important information to grasp is that the presence of harmonics in electrical systems means current and voltage are distorted. In distribution networks, harmonics flowing represent disturbances in the flow of electricity. The quality of electrical power has deteriorated and it will effect the efficiency of the system. Some of the most common risks linked to harmonics are:

  • malfunctioning of microprocessor-based equipment.
  • overheating in neutral conductors. transformers, or induction motors.
  • deterioration or failure of power factor correction capacitors.
  • erratic operation of breakers and relays.
  • pronounced magnetic fields near transformers and switch gear.

The presence of harmonics does not mean your yacht’s electrical systems will crash. Most power distribution systems are built with a certain “stiffness” that protects the susceptibility of the equipment. What will increase is the nonperformance/ failures in sensitive components due to high harmonic voltage and/or current levels. Sometimes the “source” of the harmonic pollution will run properly with little to no effect,  but the disturbance will be carried through the distribution system and effect more susceptible equipment. This is why it’s important to have trained professionals, TESS electricians, analyze and detect the true source of the problem.

Total Harmonic Distortion (THD):

“Total harmonic distortion, or THD, is the summation of all harmonic components of the voltage or current waveform compared against the fundamental component of the voltage or current wave.”  An example, given a 60Hz fundamental waveform, the 2nd, 3rd, 4th, and 5th harmonic components will be at 120Hz, 180Hz, 240Hz, and 300Hz respectively. Harmonic distortion is the degree to which a waveform deviates from its pure sinusoidal values. Again, this is pretty complicated and we don’t expect everyone to follow. What our job as trained engineers and technicians is to analyze the percentages related to the harmonic distortion and determine the severity of the situation. As stated in IEEE 519-1992 the recommended voltage distortion limit is 5%, THD, and 3% for individual harmonics. Any severity greater than these percentages dictate our efforts to find, and mitigate the problem.


Harmonics Analysis Report:

Is your yacht’s electrical system in need of a cost effective preventative maintenance plan? Have components and equipment on board started acting up? Tess service is here to help! Using a Dranetz Power Guide 4400, Power Quality Analyzer, a Tess electrician will test the system quickly and efficiently, providing a detailed report which gives the Captain, Engineer, or any other primary stakeholders,  the important information needed to address the problem.

For more information or to set up a FREE consultation contact TESS Electrical Sales & Service at 954-583-6262.



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