Author Archives: PQBlog

Variable Frequency Drive (VFD) Testing Applications

Published by Dranetz Technologies, Inc. VFD motor controls have become very popular for both retrofits and in new applications. They offer increased energy efficiency, potential for less motor wear, lower startup currents and more. Potential disadvantageous include producing harmonics and damaged motors if they are not controlled properly. VFD’s use a Pulse Width Modulated (PWM) voltageContinue reading “Variable Frequency Drive (VFD) Testing Applications”

What is Contact Resistance Test and Why is Contact Resistance Testing Done

Published by Carelabs (Carelabz), Website: carelabz.com What is Contact Resistance Contact resistance is the resistance to current flow, due to surface conditions and other causes, when contacts are touching one another (in the closed condition of the device). This can occur between contacts of:  Breakers  Contactors  Relays  Switches  Connectors  Other switching devices  Contact resistance testing alsoContinue reading “What is Contact Resistance Test and Why is Contact Resistance Testing Done”

Hot Stuff! Power Monitoring on Live Circuits Can Be Done Safely

Published by Michael Daish, Summit Technology, Inc, Walnut Creek, CA Introduction Our modern technological world depends on systems and processes that require 24 x 7 x 365 operation. When their electrical infrastructures need maintenance it must inevitably be performed on live circuits. This article discusses a procedure to keep workers safe when performing “hot work”.Continue reading “Hot Stuff! Power Monitoring on Live Circuits Can Be Done Safely”

What problems do non-linear loads and harmonics create?

Published by Mirus International Inc., [2010-01-08] MIRUS-FAQ001-B2, FAQ’s Harmonic Mitigating Transformers, 31 Sun Pac Blvd., Brampton, Ontario, Canada. L6S 5P6. Most power systems can accommodate a certain level of harmonic currents but will experience problems when they become a significant component of the overall load. As these higher frequency harmonic currents flow through the powerContinue reading “What problems do non-linear loads and harmonics create?”

A Case Study on EMI Noise adversely affecting the performance & reliability of Robotics & Automation

Published by J A Simon, Chief Executive, Waveforms, Email: waveformspower@gmail.com, Website: http://www.waveforms.co.in Automation improves productivity but it can also derail the automation process due to the issue of harmonics & Emi (high-frequency noise). This case study is about how to improve the reliability, electrical efficiency, & power quality of robotics & automation. This real-time caseContinue reading “A Case Study on EMI Noise adversely affecting the performance & reliability of Robotics & Automation”

Dranetz HDPQ Family Generator & Mission Critical Testing

Published by Dranetz Technologies, Inc. INTRODUCTION Data centers, hospitals, mission critical and other facilities rely on standby power. This is often generators that are ready to carry the load if there is an interruption in the primary power source. Such facilities often have UPS systems for a seamless transition to standby power, and to carry theContinue reading “Dranetz HDPQ Family Generator & Mission Critical Testing”

Learn About Residual Current Device Testing and Safety

Published by Carelabs (Carelabz), Website: carelabz.com Residual Current Device offer a level of personal protection that ordinary fuses and circuit-breakers cannot provide. Residual Current Devices, or RCDs. are safety switches that prevent people from getting electrocuted in homes and businesses. The device monitors the flow of electricity as it enters a property from the main distribution panel. A surge ofContinue reading “Learn About Residual Current Device Testing and Safety”

Power Quality Problems and New Solutions

Published by A. de Almeida, L. Moreira, J. Delgado, ISR – Department of Electrical and Computer Engineering, University of Coimbra, Pólo II, 3030-290 Coimbra (Portugal), Phone: +351 239 796 218, fax: +351 239 406 672, E-mail: adealmeida@isr.uc.pt, licinio@isr.uc.pt, Jdelgado@elect.estv.ipv.pt. Abstract: In this paper, the main Power Quality (PQ) problems are presented with their associated causesContinue reading “Power Quality Problems and New Solutions”

What is an SMPS and how does it generate harmonics?

Published by Mirus International Inc., [2010-01-08] MIRUS-FAQ001-B2, FAQ’s Harmonic Mitigating Transformers, 31 Sun Pac Blvd., Brampton, Ontario, Canada. L6S 5P6. What is an SMPS and how does it generate harmonics? The Switch-mode Power Supply (SMPS) is found in most power electronics today. Its reduced size and weight, better energy efficiency and lower cost make itContinue reading “What is an SMPS and how does it generate harmonics?”