Energy and Power
Time relays setting ranges explained in details
Time relays are used in control switching operations involving time delay. Most of these time relays have multiple time setting ranges and most of them are explained below. Time relays perform either on-delay or off-delay timing. An arrow is used… Read more
Apr 30, 2012 | By Edvard Csanyi
Electric Motor
Why do we find electric motor drive very important?
Electric motors impact almost every aspect of modern living. Refrigerators, vacuum cleaners, air conditioners, fans, computer hard drives, automatic car windows, and multitudes of other appliances and devices all use electric motors to convert electrical energy into useful mechanical energy…. Read more
Feb 29, 2012 | By Edvard Csanyi
Energy and Power
Using VLT AQUA Drive in submersible pump application
The system consists of a submersible pump controlled by a Danfoss VLT AQUA Drive and a pressure transmitter. The transmitter gives a 4-20 mA feedback signal to the VLT AQUA Drive, which keeps a constant pressure by controlling the speed… Read more
Jan 30, 2012 | By MarkoCvrkota
Electric Motor
How to select AC converter for VSD?
Altough manufacturers’ catalogues try to make it easy as possible, there are many variables associated with the selection and rating of the optimum electric motor and AC converter for a Variable Speed Drive (VSD) application. In many cases, it requires… Read more
Jan 06, 2012 | By Edvard Csanyi
Industrial Automation
Ladder diagrams and the PLC for electrical engineers – beginners
The ladder diagram has and continues to be the traditional way of representing electrical sequences of operations. These diagrams represent the interconnection of field devices in such a way that the activation, or turning ON, of one device will turn… Read more
Dec 27, 2011 | By Edvard Csanyi
Industrial Automation
PROFIBUS at a Glance
PROFIBUS is an open, digital communication system with a wide range of applications, particularly in the fields of factory and process automation. PROFIBUS is suitable for both fast, time-critical applications and complex communication tasks. PROFIBUS communication is anchored in the… Read more
Dec 24, 2011 | By Edvard Csanyi
Industrial Automation
When we started to use PLCs after all?
PLCs (Programmable Logic Controllers) were first introduced in the 1960’s. The primary reason for designing such a device was eliminating the large cost involved in replacing the complicated relay based machine control systems. Bedford Associates (Bedford, MA) proposed something called… Read more
Dec 21, 2011 | By Edvard Csanyi
Electric Motor
Why do we need variable speed drives (VSD)?
There are many and diverse reasons for using variable speed drives. Some applications, such as paper making machines, cannot run without them while others, such as centrifugal pumps, can benefit from energy savings. In general, variable speed drives are used… Read more
Nov 25, 2011 | By Edvard Csanyi
Industrial Automation
How Stuxnet (PLC virus) spreads – Part 4
Continued from How Stuxnet (PLC virus) spreads – Part 3 » Read here Once the worm has a foothold in the Perimeter Network, it would attempt to infect any print servers and file servers it could discover. Next, the worm… Read more
Aug 18, 2011 | By Edvard Csanyi
Industrial Automation
How Stuxnet (PLC virus) spreads – Part 3
Continued from How Stuxnet (PLC virus) spreads – Part 2 » Read here Given the well-secured industrial control system described above, how could a worm like Stuxnet ever penetrate all the way to the PLCs? Yet clearly it did – Siemens… Read more
Aug 03, 2011 | By Edvard Csanyi
Electric Motor
AC motors – Protection against short circuits
Every electric motor has operating limits. Overshooting these limits will eventually destroy it and the systems it drives, the immediate effect being operating shutdown and losses. A short circuit is a direct contact between two points of different electric potential:… Read more
Jul 29, 2011 | By Edvard Csanyi
Industrial Automation
How Stuxnet (PLC virus) spreads – Part 2
Continued from How Stuxnet (PLC virus) spreads – Part 1 » Read here Stuxnet is a computer worm designed to infect Siemens SIMATIC WinCC and S7 PLC products, either installed as part of a PCS 7 system, or operating on… Read more
Jul 23, 2011 | By Edvard Csanyi
Industrial Automation
How Stuxnet (PLC virus) spreads – Part 1
The Stuxnet worm is a sophisticated piece of computer malware designed to sabotage industrial processes controlled by Siemens SIMATIC WinCC and PCS 7 control systems. The worm used both known and previously unknown vulnerabilities to install, infect and propagate, and… Read more
Jul 20, 2011 | By Edvard Csanyi
High Voltage
GIS control system
For ease of operation and convenience in wiring the GIS back to the substation control room, a local control cabinet (LCC) is provided for each circuit breaker position (Figure 1). The control and power wires for all the operating mechanisms,… Read more
May 29, 2011 | By Edvard Csanyi
Energy Efficiency
KNX automation makes buildings more efficient
In light of climate change and increasingly scarce resources, the energy-efficient operation of buildings is gaining in importance. Essential requirements for this are an energy-efficient architectural design, an insulated building exterior and modern installation engineering with a high level of… Read more
Apr 15, 2011 | By Edvard Csanyi
