Testing and Commissioning
What to check when commissioning variable speed drives
The main purpose of commissioning VSDs is to ensure that: The AC converter and motor have been correctly installed and meet the wiring and safety standards such as IEC 60364… Read more
Apr 22, 2015 | By Edvard
Electric Motor
Comparison of motor speed control methods
It is often desirable to control the motor speed, usually for reasons process control for such variables as flow or pressure. Such applications as fans and pumps often have varying… Read more
Mar 13, 2015 | By Edvard
Industrial Automation
10 Things to Consider When Selecting a High Quality Medium Voltage Drive
Medium voltage drives have been available for over 35 years, but have only recently achieved very high reliability and simplicity within the past few years. Below are 10 considerations on… Read more
Sep 17, 2014 | By Craig Hartman
Industrial Automation
Effects of Speed Variation on Rotodynamic Pumps
A rotodynamic pump is a dynamic device with the head generated by a rotating impeller. Thus, there is a relationship between impeller peripheral velocity and generated head. Peripheral velocity is… Read more
May 09, 2014 | By Edvard
Energy and Power
Effect of utility-induced surges in a steel mill with variable speed drives
A steel mill with variable speed drives (VSDs) had problems of frequent tripping of the VSDs with the indication overvoltage in AC line. Each tripping caused severe production disruption and… Read more
Feb 12, 2014 | By Edvard
Electric Motor
Keeping Motor At Correct Temperature When Connected To a Frequency Converter
When a motor is connected to a frequency converter it must be kept at the correct temperature, and this is subject to two types of influence: If the speed decreases,… Read more
Jul 05, 2013 | By Edvard
Industrial Automation
Benefits and Potential Drawbacks of VSDs
VSDs (Variable Speed Drives) offer several benefits, some of which are relatively easy to quantify, and others of which are less tangible, but there are some potential drawbacks, which must… Read more
Apr 03, 2013 | By Edvard
Electric Motor
PLC Application For Speed Control of AC Motors With Variable Speed (VS) Drive
A common PLC application is the speed control of AC motors with variable speed (VS) drives. The diagram in Figure 1 shows an operator station used to manually control a… Read more
Dec 29, 2012 | By Edvard
Industrial Automation
Basic Mechanical Terms Used In Drives Applications
Terms below are the basic mechanical terms associated with the mechanics of DC drive operation. Many of these terms are familiar to us in some other context. Force Net Force… Read more
Dec 06, 2012 | By Edvard
Variable Speed Drives
VLT Drives in Wastewater Treatment Plant Applications
The most common use of frequency converters is to drive sludge pumps, elevators, conveyers, aeration, chemical dosing, clarifiers, digesters, presses and centrifugal dewatering. In the beginning water is being pumped… Read more
Nov 22, 2012 | By MarkoCvrkota
Industrial Automation
Few Words About Frequency Converters
Since the late 1960’s, frequency converters have undergone extremely rapid changes, largely as a result of the development of microprocessor and semi-conductor technologies and their reduction in prices. However, the basic principles of… Read more
Nov 21, 2012 | By Edvard
Industrial Automation
How to Select Right Frequency Converter for Variable Speed Drive (VSD)?
Selecting of a frequency converter for variable speed drives requires a lot of experience. If the experience is not available, it is often useful to visit either a reference plant with similar… Read more
Nov 17, 2012 | By Edvard
Electric Motor
LT / Medium / HT VFD Used In the Industry (part 2)
Consider the application of a drive to a cane milling unit where the speed is to be variable from full to half rated speed. The drive is to be capable… Read more
Sep 11, 2012 | By sprabakar22
Electric Motor
LT / Medium / HT VFD Used In the Industry (1)
In modern plants, there are number of drives like Milling Plant Drive, Hydraulic Drive, DC Motor Drive and AC Motor Drive of adequate capacities are available. There is lot of… Read more
Sep 10, 2012 | By sprabakar22
Electric Motor
AC Adjustable Speed Drive (ASD) – An Overview
The simplest and least expensive way to control the speed of a process or piece of equipment is to operate all the equipment at full speed. Many applications require the… Read more
Jul 19, 2012 | By Edvard
