Last month we had a callout to a utility customer who had an ABB low harmonic 315kw VSD fail on short circuit failure, this was in the early hours of a Sunday morning and the failure was beyond an onsite repair due to the extent of the damage. So we were on site and installing a hire …

# Category: Harmonics

Sep 19 2018

## Why you must use Variable Speed Drives in pumping applications!

Variable speed drives in pumping applications Pumping applications represent a significant opportunity for applying variable speed drives (VSDs) in new, as well as retrofit installations. The majority of pumping applications need to be controlled. It is unlikely that a pump will run continuously at a maximum speed. Many analyses show that energy consumption is …

Feb 14 2018

## What are the common effects of harmonic distortion?

The distortion in the waveform in the load current of any nonlinear device causes similar changes in the voltage waveform relative to the harmonic impedance of the source network. This voltage distortion affects both the current and voltage for all other loads connected to that system. The common effects of such harmonic distortion are as …

Nov 09 2017

## What is the principle of power factor correction and protection of capacitors?

Power factor correction principle// Loads such as induction motors draw significant reactive power from the supply system, and a poor overall power factor may result. The flow of reactive power increases the voltage-drops through series reactances such as transformers and reactors, it uses up some of the current carrying capacity of power system plant and …

May 04 2017

## What are harmonics and what do they do?

What are harmonics? The harmonics allow to represent any periodic waveform. In fact, according to Fourier’s theorem, any periodic function of a period T may be represented as a summation of: A sinusoid with the same period T; Some sinusoids with the same frequency as whole multiples of the fundamental; A possible continuous component, if the function …

Nov 21 2016

## How do you diagnose a potential harmonics related problem?

4 steps to diagnose a potential harmonics related problem // If a plant engineer suspects that he might have a harmonics related problem, the following steps can easily be performed as an initial investigation into potential problems: Step 1 Look for symptoms of harmonics as listed in Table 1 below. If one or more of …