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.

Study of Fault Arc Protection Based on UV Pulse Method in High Voltage Switchgear

2013 ◽  
Vol 853 ◽  
pp. 641-645
Author(s):  
Cheng Xu ◽  
Jia Xiang Sun ◽  
Jin Gang Wang ◽  
Yi Luo
Keyword(s):  
Ultraviolet Radiation ◽  
High Voltage ◽  
Pulse Method ◽  
Electrical Equipment ◽  
Electric Arc ◽  
Protection System ◽  
New Technique ◽  
Arcing Faults ◽  
The Relationship

Based on the relationship between electrical equipment discharge and ultraviolet radiation, this paper proposed the use of UV pulse method to detect switchgear arcing faults. Switchgear protection system based on this new technique detects arcing faults by analyzing the ultraviolet produced by electric arc. The technique was implemented and tested in laboratory, and results verified the performance of the protection system; its capable to calculate the number of UV pulses and cut off faults fast and precisely.

Experimental Study of Fault Arc Protection Based on UV Pulse Method in High Voltage Switchgear

2014 ◽  
Vol 15 (3) ◽  
pp. 247-252
Author(s):  
Jingang Wang ◽  
Cheng Xu ◽  
Jiaxiang Sun
Keyword(s):  
Experimental Study ◽  
Ultraviolet Radiation ◽  
High Voltage ◽  
Pulse Method ◽  
Electrical Equipment ◽  
Electric Arc ◽  
Protection System ◽  
New Technique ◽  
Arcing Faults ◽  
The Relationship

Abstract Based on the relationship between electrical equipment discharge and ultraviolet radiation, this paper proposed the use of UV pulse method to detect switchgear arcing faults. Switchgear protection system based on this new technique detects arcing faults by analyzing the ultraviolet produced by electric arc. This technique was implemented and tested in laboratory, and the performance of the protection module was verified: it is capable of calculating the number of UV pulses quickly and precisely, which indicates the intensity of fault arc, and therefore it can be applied to arcing faults protection system for detecting faults.

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