A short circuit condition occurs when the insulation between the phase conductors fails and the load current level exceeds the normal locked rotor current levels that a motor would draw during start-up. The fault level of the motor feeder supply determines the current level during a short circuit and can be as high as 15 to 50 times the motor full load current value.
A short circuit fault is a system level fault, which means that it will compromise the stability of the entire network and result in total power loss of the healthy drive and shut down the entire process. The MCCB is a maintenance specific item that can still appear to be functional but may not be, and will result in a catastrophic failure on the next fault clearance.
NewElec’s MA motor protection relay is able to protect against thermal overloads, locked rotor and running stall or jam protection. The MA also protects against short circuit faults and automatically takes care of trip co-ordination so that the main contactor is not used to disrupt high energy faults.
Additional MA features include real time and date stamping recorded by the relay for the last four trips, a recording utility of actual RMS loads, thermal conditioning, mains phase voltage, line voltage, as well as the status of digital inputs and output contacts. The user has the possibility of expanding the unit for fieldbus communications via Profibus DP, Modbus RTU and Canbus protocols.
Retrofitting for sustainability Schneider Electric South Africa
Electrical Power & Protection
As budgets tighten and sustainability targets increase, retrofit and modernisation strategies are gaining traction across Africa, allowing organisations to upgrade only what limits performance while preserving existing infrastructure and extending asset life.
Read more...USB-Datalogger for voltage 0 to 30 V DC Vepac Electronics
Electrical Power & Protection
The PeakTech 5186 is a data logger for DC voltages from 0 V to 30 V with terminals on the top of the device.
Read more...Pole-top boxes for smarter, more secure electricity networks
Electrical Power & Protection
As South Africa accelerates the rollout of smart prepaid electricity metering, innovative enclosure technology from Power Process Systems is helping utilities improve network security, reduce electricity theft and protect critical electrical infrastructure.
Read more...Simplifying electrical design compliance
Electrical Power & Protection
Referro Systems highlights how Rockwell Automation’s Global SCCR Tool simplifies short-circuit current rating compliance for complex industrial electrical systems.
Read more...Engineering resilience into Africa’s energy future
Electrical Power & Protection
Zutari’s managing director of water explains how Burundi’s landmark Jiji and Mulembwe hydropower projects demonstrate what resilient, climate-adapted infrastructure delivery looks like – and what this means for Africa’s energy future.
Read more...Voltage Tester with LED-Display Vepac Electronics
Electrical Power & Protection
The PeakTech 1094 is a reliable and robust two-pole voltage tester that has been specially developed for the safe and precise measurement of AC and DC voltages in the 12 to 400 V range.
Read more...Schneider Electric launches circuit breaker for cost-effective LV protection Schneider Electric South Africa
Electrical Power & Protection
Schneider Electric has launched its EasyPact CVS C4 moulded case circuit breaker in South Africa, extending the Easy series to 1 600 A and giving consultants, contractors, and end users a cost-effective solution for non-critical low-voltage applications.
Read more...Schneider Electric launches cost-effective, high-performance LV protection Schneider Electric South Africa
Electrical Power & Protection
Schneider Electric has launched its EasyPact NW air circuit breaker in South Africa, extending its Easy series portfolio with a cost-effective solution for non-critical low-voltage applications in commercial, industrial and residential projects.
Read more...SF6-free switchgear brings digital intelligence to mining Schneider Electric South Africa
Electrical Power & Protection
Combining pure-air switchgear with embedded digital intelligence helps mines cut greenhouse gas emissions, improve safety and meet sustainability targets while enabling real-time visibility into critical electrical assets.
Read more...Turning plastic waste into clean hydrogen
Electrical Power & Protection
Researchers have developed a solar-powered process that converts plastic waste into hydrogen and useful industrial chemicals while using spent acid from vehicle batteries. The approach could help create a circular system for dealing with several challenging waste streams at the same time.
While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.
printer friendly version