The Effect of Hazardous Locations on Electrical Equipment Short-Circuit Ratings: Copyright Material IEEE, Paper No. PCIC-2018-50

2018 ◽  
Author(s):  
Rehanul Hasan ◽  
Rick Mendler ◽  
Behzad Nejad
Keyword(s):  
Short Circuit ◽  
Electrical Equipment ◽  
Copyright Material

scholarly journals Development of a Method and Algorithm for Inhibiting an Automatic Transfer Switch of the Circuit Breaker for a Sustained Short-Circuit

2020 ◽  
Vol 220 ◽  
pp. 01011
Author(s):  
Igor Nikolaevich Fomin ◽  
Roman Pavlovich Belikov ◽  
Tatyana Anatolyevna Kudinova ◽  
Nailya Kamilevna Miftakhova
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Electrical Equipment ◽  
Ring Network ◽  
Circuit Breakers ◽  
Emergency Situations ◽  
Short Circuit Currents

Circuit breakers with automatic transfer switches (ATS) are designed in such a way that when the voltage disappears during a short-circuit (SC) in the ring network line, the ATS device is triggered. At the same time, its switch is turned on at short-circuit, then it is turned off with acceleration. Even a shortterm switching on of the automatic transfer switch for a sustained short-circuit leads to emergency situations [1,2]. The electrical equipment of the ring network spare line is exposed to high emergency short-circuit currents, and the consumers powered by the spare transformer are turned off. It is possible to minimize and eliminate the damages caused by the above mentioned cases by inhibiting the switching on of the circuitbreaker of the automatic transfer switch.

scholarly journals Thyristor Arc Eliminator for Protection of Low Voltage Electrical Equipment

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2749 ◽  
Author(s):  
Karol Nowak ◽  
Jerzy Janiszewski ◽  
Grzegorz Dombek
Keyword(s):  
Lower Cost ◽  
Low Voltage ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Power Network ◽  
System Operation ◽  
Test Circuit ◽  
Wide Range ◽  
Short Circuit Currents ◽  
Electrical Apparatus

The paper presents the layout of two opposing thyristors working as an Arc Eliminator (AE). The presented solution makes it possible to protect an electrical apparatus against the effects of an arcing fault. An Arc Eliminator is assumed to be a device cooperating with the protected apparatus. Thyristors were used because of their speed of operation and a relatively lower cost compared to other semiconductors with the same current-carrying capacity. The proposed solution, as one of the few currently available, makes it possible to eliminate the fault arc—both at short-circuit currents and current values to which overcurrent protections do not react. A test circuit was designed and made to study the effectiveness of the thyristor arc eliminator. A series of tests was carried out with variable impedance in the arc branch, including the influence of circuit inductance on arc time. It was found that the thyristor arc eliminator effectively protects devices powered from a low voltage power network against the effects of a fault or arc fault. The correctness of system operation for a wide range of impedance changes in the circuit feeding the arc location was demonstrated.

Arc Flash Hazard Analysis in Traction Power Substations

2009 ◽  
Author(s):  
Kinh D. Pham ◽  
Robert Jones
Keyword(s):  
Hazard Analysis ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Rail Transit ◽  
Arcing Faults ◽  
Insulation Failure ◽  
Arc Flash ◽  
Transit Agencies ◽  
Ionized Air ◽  
Dc Arc

Arc flash hazards can result from accidents or equipment deterioration such as dropping tools, accidental contact with electrical equipment, build up of conductive dust, corrosion, condensation, over-voltage stress, or insulation failure. An arc is produced when electric current passes through ionized air after an initial flash over or short circuit, resulting in a flash that could produce significant heat, with temperature in excess of 35,000°F. The extremely high temperature of an electric arc can cause major burns within ten feet and fatal burns within five feet of an arc flash. Recently enacted guidelines and regulations by OSHA and NFPA 70E regarding arc flash hazards have compelled many rail transit agencies to require that an arc flash hazard analysis be performed. The purpose of this analysis is to determine the potential risk of arc faults at every switchgear and electrical panel board to which a worker may be exposed. To comply with OSHA and NFPA, appropriate work practices and personal protective equipment (PPE) must be utilized to reduce the risks associated with arc flashes. Several methods for calculating the arc-flash hazard have been developed. This paper will examine and discuss the following three methods: a) the Ralph H. Lee’s theoretical model, b) the NFPA 70E equations and tables, and c) the IEEE Std 1584 methods. None of the above methods addresses arcing faults in DC switchgear. To date, there is no written standard for DC arc flash hazard analysis. DC arcing faults and calculation methods are discussed. Sample arc flash hazard analysis from a recent rail transit project is included.

Design of High-Rise Building’s Monitoring System for Electric Fire Base on CAN Bus

2015 ◽  
Vol 734 ◽  
pp. 104-108
Author(s):  
Shi Wei Sun ◽  
Xin Tong Liu ◽  
Wei Liu ◽  
Qi Yang
Keyword(s):  
Monitoring System ◽  
Leakage Current ◽  
Power Distribution ◽  
Can Bus ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Current Signal ◽  
Fire Monitoring ◽  
High Rise ◽  
Electric Power Distribution

This paper accomplished a system of high-rise building’s fire monitoring system based on CAN bus. It is applied in avoiding the harm of leakage current , over current and short circuit, and protecting electric power distribution circuits and electrical equipment, thus to prevent the occurrence of electrical fire. The monitoring system can detect phase current signal and the leakage current signal, and can display real-time and alarm. It also can proceed network service and complete the distributed remote control and fault diagnosis. Practice shows that the system the characteristics of high precision, safe and reliable, low rate of false positives, easy operation and maintenance, etc .It can satisfy the demand of large high-rise building electrical fire.

scholarly journals A study on reported fire incidents in major hospitals of India

2020 ◽  
Vol 7 (10) ◽  
pp. 3896
Author(s):  
Shyam Siddharth Rao Patharla ◽  
Souri Reddy Pyreddy ◽  
Shilpa N. Panthagani
Keyword(s):  
Intensive Care ◽  
Short Circuit ◽  
Fire Detection ◽  
Electrical Equipment ◽  
Common Source ◽  
Common Cause ◽  
Air Conditioners ◽  
Mainstream Media ◽  
News Reports ◽  
Media Reports

Background: An uncontrolled fire is dangerous especially in the healthcare establishments as they frequently cater to the sick who often require assistance. We studied the various aspects of fire incidents that occurred in major Indian hospitals through media reports in the past decade (January 2010 to December 2019). It is our intention that this study would act as a reference to prioritize and stimulate research in hospital fire safety.Methods: An extensive internet search was done for news reports/articles on fire incidents in major hospitals by mainstream media outlets. Major hospitals were those with more than 100 in-patient beds.Results: 33 major fire incidents were reported during the defined period. The most common cause of fire was due to electrical short circuit 78% with air conditioners being the most common source. Functional firefighting systems were reported in 19 incidents. Fires originated at or near intensive care units (ICU’s) in 10 instances. 72.72% accidents occurred at night (8:01 p.m. to 7:59 a.m.). Casualties were reported in 39% of the fire accidents.Conclusions: The most common cause of fire accidents is electrical short circuit. Hospitals need to prioritize periodic testing of firefighting systems and regular training of staff on their use. Judicious placement of electrical equipment combined with oxygen monitoring devices in intensive care areas is recommended. Storage of flammable materials and placement of central gas supply points should be away from the vicinity of patient care areas and always in conjunction with robust fire detection and control methods. Hospitals should adhere to their planned capacity.

scholarly journals EQUIPMENT DESIGN AND TESTING TRANSFER VOLTAGE REFERRING TO IEC 156 STANDARD USING VIRGIN COCONUT OIL (VCO) WITH OIL TEMPERATURE CONDITIONING

2021 ◽  
Vol 2 (2) ◽  
pp. 001-006
Author(s):  
Ansyori Ansyori ◽  
Irsyadi Yani ◽  
Eric Rahman
Keyword(s):  
Breakdown Voltage ◽  
Short Circuit ◽  
Coconut Oil ◽  
Electrical Equipment ◽  
Transformer Oil ◽  
Virgin Coconut Oil ◽  
Electrical Failure ◽  
Environmentally Safe ◽  
Insulating Liquid ◽  
Design And Testing

Isolation is a separator between conductors in electrical equipment that prevents flashover, resulting in a short circuit or electrical failure. Isolation is critical in electrical appliances, exceptionally High Voltage Power Equipment (HVPE), to ensure the safety of circuit breakers, capacitors, and transformers. In addition to being an isolator, the insulating liquid material also serves to cool the heat generated by electrical appliances. Isolator with mineral oil-based transformer has various environmental issues, including non-biodegradability, non-renewability, and rarity. Because it is environmentally safe and extensively used, virgin coconut oil (VCO) is an alternative transformer oil insulation. This study aims to determine the properties of Virgin Coconut Oil (VCO) breakdown voltage using the IEC 156 standard and oil temperature conditioning. According to the test results, the oil breakdown voltage before heating (at room temperature) is 14 kV, which is much below the IEC 156 standard, and the breakdown voltage after heating at 90 ° is 35 kV, and 110 ° is 40 kV, which is even higher than the IEC 156 requirement

scholarly journals FACTORS OF FIRE HAZARD OF ELECTRICITY-GENERATING EQUIPMENT

Fire Safety ◽  
2019 ◽  
pp. 43-46
Author(s):  
I. P. Kravets ◽  
O. I. Bashynskiy ◽  
A. P. Kushnir ◽  
O. V. Shapovalov
Keyword(s):  
Fire Safety ◽  
Fire Hazard ◽  
Short Circuit ◽  
Electric Energy ◽  
Electrical Equipment ◽  
Correct Choice ◽  
Main Task ◽  
Prevention Measures ◽  
Strict Adherence ◽  
Generating Equipment

The article deals with the problems of fire hazard of electricity-generating equipment during their exploitation. Intensive electrification of industrial and residual objects leads to the saturation of these objects with different electricity-generating equipment. Functioning of such equipment is accompanied with high heat emission and contains significant fire hazard. The electric current in an electrical conductor produces heat, when electric energy turns into thermal. All electrical equipment must be produced in strict adherence to fire safety rules and requirements. Ignoring these requirements causes heating of conductors through all the length, spunking of isolation, sparkling and, as a result, breaking-out of fire. Therefore, reducing the probability of fire even in the cases of abnormal work, wrong exploitation and foreseen refuses is the main task during planning and exploitation of electrical equipment and also during selection of structural materials. The primary purpose of fire prevention measures in the electrical equipment is avoiding of its self-ignition, and localization of fire after the self-ignition of electricity-generating equipment. Fire safety during exploitation of electricity-generating equipment depends on its technical state. Correct choice of conductor cross section is very important. Protection stage of electrical equipment, type of wiring, and cable laying method must comply with environmental conditions and have the proper climatic implementation and placement category. Proper protective devices from a short circuit and overloads must be used. Their operating values must be also foreseen. All above-mentioned measures prevent fires and explosions during exploitation of electrical equipment. Key

MODELING OFDISTRIBUTION TRANSFORMERS BY A 3-D NUMERICAL TECHNIQUE

2020 ◽  
pp. 56-62
Author(s):  
Vuong
Keyword(s):  
Magnetic Flux ◽  
Numerical Technique ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Cover Plate ◽  
Magnetic Vector Potential ◽  
Practical Application ◽  
Leakage Flux ◽  
Electromagnetic Quantities ◽  
Flux Leakage

Modeling of electromagnetic quantities (magnetic flux, leakage flux, eddy current loss, and electromagnetic force) in distributed power transformers remarkably plays an essential role for researchers and designers in the calculation and production of electrical equipment in general and transformer designs in particular. In the frame of this research, the distribution of magnetic flux densities along the tank wall and cover plate, the leakage flux in air regions, and the forces for both rated and short circuit modes in the windings of the transformer are computed/simulated via a 3-D numerical method. The method is herein developed with magnetic vector potential formulations and is applied to a practical application of the distributed transformer (630kVA-22/0,4kV).

High-voltage electrical equipment in electrical power systems: diagnostics, defects, damage, monitoring

2019 ◽  
Author(s):  
Александр Хренников ◽  
Alexander Khrennikov
Keyword(s):  
Power Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Electrical Equipment ◽  
Diagnostic Methods ◽  
Power Transformers ◽  
Electrical Power Systems ◽  
The Impact ◽  
Short Circuit Currents ◽  
Detection Of Defects

The analysis of the main methods of diagnostics of electrical equipment for detection of defects and damages in the course of operation is presented. Analysis of the effectiveness of the main diagnostic methods is accompanied by examples of detection of defects and damage to specific equipment: power transformers, reactors, current and voltage transformers, disconnectors, turbogenerators, OPN, etc. Examples of damage and investigation of technological violations of oil-filled transformer-reactor equipment during operation, associated with the loss of electrodynamic resistance of the windings during the flow of through short-circuit currents (short-circuit). The analysis of efficiency of application of methods of diagnostics at detection of defects and damages of power transformers because of the impact of fault current. The questions of electrodynamic tests of power transformers (reactors) for resistance to short-circuit currents, which serve as a tool to improve the reliability of their design, are considered.

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