Pub Date : 2010-06-21DOI: 10.1109/PAPCON.2010.5556520
D. Durocher
Many legacy low and medium-voltage unit substations installed today are based upon older designs that took advantage of reduced first cost “opportunities” allowed by existing installation codes and standards. Fast-forward to how these substation designs fair in safety and reliability today, particularly in industrial process applications found in cement, pulp and paper, petroleum & chemical and others, some of the exercised “opportunities” applied in the past begin to look more like liabilities than assets. Legacy engineering decisions once thought to be prudent take on new meanings today, particularly when these decisions are viewed through the lens of emerging new workplace safety standards. The critical issue of addressing destructive arc-flash hazards associated with persons working on or around energized electrical equipment must now be considered. Because traditional substation designs often appeared to involve some compromise regarding both safety and reliability, a design team of a major process industry user took a fresh look at unit substation design. The design review took place in conjunction with construction of a Greenfield plant built in the spring of 2009 in the USA. This paper will review the design limitations of traditional unit substation configurations, offer an overview of the alternatives considered by the Greenfield site project team, and discuss technical and safety validation of the design that was ultimately selected and installed. Economic comparisons to traditional designs, changes in the owner operating and safety procedures for plant personnel as a result of the engineering design changes, and overall design acceptance by operations will also be reviewed in this paper.
{"title":"Considerations in unit substation design to optimize reliability and electrical workplace safety","authors":"D. Durocher","doi":"10.1109/PAPCON.2010.5556520","DOIUrl":"https://doi.org/10.1109/PAPCON.2010.5556520","url":null,"abstract":"Many legacy low and medium-voltage unit substations installed today are based upon older designs that took advantage of reduced first cost “opportunities” allowed by existing installation codes and standards. Fast-forward to how these substation designs fair in safety and reliability today, particularly in industrial process applications found in cement, pulp and paper, petroleum & chemical and others, some of the exercised “opportunities” applied in the past begin to look more like liabilities than assets. Legacy engineering decisions once thought to be prudent take on new meanings today, particularly when these decisions are viewed through the lens of emerging new workplace safety standards. The critical issue of addressing destructive arc-flash hazards associated with persons working on or around energized electrical equipment must now be considered. Because traditional substation designs often appeared to involve some compromise regarding both safety and reliability, a design team of a major process industry user took a fresh look at unit substation design. The design review took place in conjunction with construction of a Greenfield plant built in the spring of 2009 in the USA. This paper will review the design limitations of traditional unit substation configurations, offer an overview of the alternatives considered by the Greenfield site project team, and discuss technical and safety validation of the design that was ultimately selected and installed. Economic comparisons to traditional designs, changes in the owner operating and safety procedures for plant personnel as a result of the engineering design changes, and overall design acceptance by operations will also be reviewed in this paper.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130458072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-20DOI: 10.1109/CITCON.2010.5470070
G. Fox
Coordination studies utilize time current curves to determine the extent to which upstream overcurrent protective device pick-up and time delays must be increased to provide selectivity with downstream devices. These increases in device time delays result in increased let through energy and greater arc flash hazards. Advanced breaker trip unit technologies, including zone selective interlock, maintenance mode, and enhanced time current curve adjustment options, limit let through energy and reduce arc flash hazards without compromising system selectivity. This paper will detail how these new technologies can be utilized within industrial and commercial facilities to enhance system reliability and protect personnel.
{"title":"Methods for limiting arc flash hazards while maintaining system selectivity","authors":"G. Fox","doi":"10.1109/CITCON.2010.5470070","DOIUrl":"https://doi.org/10.1109/CITCON.2010.5470070","url":null,"abstract":"Coordination studies utilize time current curves to determine the extent to which upstream overcurrent protective device pick-up and time delays must be increased to provide selectivity with downstream devices. These increases in device time delays result in increased let through energy and greater arc flash hazards. Advanced breaker trip unit technologies, including zone selective interlock, maintenance mode, and enhanced time current curve adjustment options, limit let through energy and reduce arc flash hazards without compromising system selectivity. This paper will detail how these new technologies can be utilized within industrial and commercial facilities to enhance system reliability and protect personnel.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127251256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489906
Y. Ke, Y. Chuang, H. Chuang, Yuan-Kang Wu, C. Chang
This study implements a driver circuit for a liquid crystal display backlight source to develop a dc-ac converter with few components, which is then connected to a cold cathode fluorescent lamp as the load. The circuit configuration includes a push-pull circuit, which provides parallel resonance and acts as a transformer that generates a sinusoidal waveform across the secondary winding. The circuit provides sufficiently high ac voltage to drive the lamps. Additionally, the impedance characteristics of the resonance circuit can be modified to set the dimming frequency. The work describes in detail the operating principles and design of the parameters of the resonance circuit. Experimental results demonstrate the theoretical effectiveness of the developed circuit.
{"title":"Self-excited electronic ballast for cold cathode fluorescent lamps","authors":"Y. Ke, Y. Chuang, H. Chuang, Yuan-Kang Wu, C. Chang","doi":"10.1109/ICPS.2010.5489906","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489906","url":null,"abstract":"This study implements a driver circuit for a liquid crystal display backlight source to develop a dc-ac converter with few components, which is then connected to a cold cathode fluorescent lamp as the load. The circuit configuration includes a push-pull circuit, which provides parallel resonance and acts as a transformer that generates a sinusoidal waveform across the secondary winding. The circuit provides sufficiently high ac voltage to drive the lamps. Additionally, the impedance characteristics of the resonance circuit can be modified to set the dimming frequency. The work describes in detail the operating principles and design of the parameters of the resonance circuit. Experimental results demonstrate the theoretical effectiveness of the developed circuit.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128324864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489877
P. Sutherland
A “nuisance trip” of a microprocessor based transformer differential relay was observed, with an unknown cause. The relay settings were modified with a higher pickup and an alarm at a more sensitive setting. The relay was then able to capture an event, which then did not cause tripping. The results were analyzed and found to be caused by energization of a downstream transformer. In addition, the CT ratio on the transformer primary was excessively high, which was corrected by auxiliary CTs. Based on these results, no further changes needed to be made to the relay settings.
{"title":"Investigation of nuisance trips in microprocessor based transformer differential relay","authors":"P. Sutherland","doi":"10.1109/ICPS.2010.5489877","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489877","url":null,"abstract":"A “nuisance trip” of a microprocessor based transformer differential relay was observed, with an unknown cause. The relay settings were modified with a higher pickup and an alarm at a more sensitive setting. The relay was then able to capture an event, which then did not cause tripping. The results were analyzed and found to be caused by energization of a downstream transformer. In addition, the CT ratio on the transformer primary was excessively high, which was corrected by auxiliary CTs. Based on these results, no further changes needed to be made to the relay settings.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124827826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489889
G. Parise, L. Parise
The ecodesign is developing a strong encouragement towards the energy saving balanced with other performances and requires new approaches that this paper begins to highlight. The distribution system management has to facilitate innovations, changes and the complying with these improvements. Together to energy saving, reduced voltage-drops and losses, the system modeling with components of smaller size allows to guarantee a higher value of current densities, reduced volume of conductors and other related goals of efficiencies. Microsystem criteria are highlighted introducing few specific parameters to assist the system design that rises generally as a comprehensive solution of a non linear system of many elements, grouping adequately the supplying loads, adopting circuit with conductors/cables in bunch, in loop or in rope design.
{"title":"Microsystem criteria in electrical installations ecodesign","authors":"G. Parise, L. Parise","doi":"10.1109/ICPS.2010.5489889","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489889","url":null,"abstract":"The ecodesign is developing a strong encouragement towards the energy saving balanced with other performances and requires new approaches that this paper begins to highlight. The distribution system management has to facilitate innovations, changes and the complying with these improvements. Together to energy saving, reduced voltage-drops and losses, the system modeling with components of smaller size allows to guarantee a higher value of current densities, reduced volume of conductors and other related goals of efficiencies. Microsystem criteria are highlighted introducing few specific parameters to assist the system design that rises generally as a comprehensive solution of a non linear system of many elements, grouping adequately the supplying loads, adopting circuit with conductors/cables in bunch, in loop or in rope design.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129446943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489893
G. Parise, L. Martirano, Massimo Mitolo, T. Baldwin, S. Panetta
Street lighting installations are publicly accessible electrical pieces of equipment out of the physical control of who operates/owns them. Street lighting systems are a typical case of low-voltage loads, distributed in a large area and collectively protected by the same protective device. In fault conditions, hazardous potentials may appear on the metal parts of such equipment, and expose persons to shock hazards. To reduce such risk, different solutions for the grounding are available. The Standard IEC 60364, and a current worldwide tendency, seem to encourage the use of Class II components, that is, equipment with double or reinforced insulation, for all the elements of the street light system (i.e. wiring systems, light fixtures, etc.). These authors examine possible technical alternatives in light of IEC standards, and propose to increase the safety of Class II metal poles by adopting a circuitry within lighting systems panelboards to monitor their double insulation-to-ground.
{"title":"Grounding of distributed low-voltage loads: The street lighting systems","authors":"G. Parise, L. Martirano, Massimo Mitolo, T. Baldwin, S. Panetta","doi":"10.1109/ICPS.2010.5489893","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489893","url":null,"abstract":"Street lighting installations are publicly accessible electrical pieces of equipment out of the physical control of who operates/owns them. Street lighting systems are a typical case of low-voltage loads, distributed in a large area and collectively protected by the same protective device. In fault conditions, hazardous potentials may appear on the metal parts of such equipment, and expose persons to shock hazards. To reduce such risk, different solutions for the grounding are available. The Standard IEC 60364, and a current worldwide tendency, seem to encourage the use of Class II components, that is, equipment with double or reinforced insulation, for all the elements of the street light system (i.e. wiring systems, light fixtures, etc.). These authors examine possible technical alternatives in light of IEC standards, and propose to increase the safety of Class II metal poles by adopting a circuitry within lighting systems panelboards to monitor their double insulation-to-ground.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134269456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489896
G. Parise, L. Martirano, G. Fox
The earthquake causes serious problems to the functional reliability and continuity of supply of electrical power systems particularly in exposed and sensitive structures as hospitals and strategic buildings. The paper discusses the need to study the requirements for the design and installation of electrical power systems in buildings subject to seismic hazard. Mechanical and electrical criteria for the design and the installation are recommended to be graduated according to building occupancy categories (as hospitals, strategic buildings). At least three levels of performance are identified for equipment. An important goal is to coordinate the non structural designing criteria with a layout of the system architecture that avoids or confines as possible intrinsically in a “duty-free” zone the seismic exposition and limits the same installation problems. A special power distribution, “brush-distribution”, has a laid structure suitably for the strategic buildings that are at risk for seismic event. Other general design criteria, such as a guarantee for the supply continuity, the system reliability and the system protection, have a special use in these appliances. The paper compares the brush distribution against the recommendations for the non structural components issued by the National Earthquake Hazard Reduction Program (NEHRP) (edition 2009).
{"title":"Electrical power systems availability in buildings exposed to seismic hazard","authors":"G. Parise, L. Martirano, G. Fox","doi":"10.1109/ICPS.2010.5489896","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489896","url":null,"abstract":"The earthquake causes serious problems to the functional reliability and continuity of supply of electrical power systems particularly in exposed and sensitive structures as hospitals and strategic buildings. The paper discusses the need to study the requirements for the design and installation of electrical power systems in buildings subject to seismic hazard. Mechanical and electrical criteria for the design and the installation are recommended to be graduated according to building occupancy categories (as hospitals, strategic buildings). At least three levels of performance are identified for equipment. An important goal is to coordinate the non structural designing criteria with a layout of the system architecture that avoids or confines as possible intrinsically in a “duty-free” zone the seismic exposition and limits the same installation problems. A special power distribution, “brush-distribution”, has a laid structure suitably for the strategic buildings that are at risk for seismic event. Other general design criteria, such as a guarantee for the supply continuity, the system reliability and the system protection, have a special use in these appliances. The paper compares the brush distribution against the recommendations for the non structural components issued by the National Earthquake Hazard Reduction Program (NEHRP) (edition 2009).","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131290012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489883
G. T. Orr, S. Cooper, C. Mozina
At many industrial facilities, distribution busses serving critical loads are supplied from two power sources. Typically, this bus arrangement is in a main-tie-main arrangement. Upon the loss of the normal power source, critical motor loads must be transferred to the alternate source without damaging the equipment, and ideally, without interrupting the process. In this application, two digital motor bus transfer systems were installed to transfer two 4 KV busses to two sources. This paper describes the steps to applying a digital motor bus transfer system to medium-voltage switchgear at a large chemical company including the feasibility analysis, available transfer methods, input/output considerations, settings, and commissioning methods. A summary of actual operations data to date and lessons learned is also included.
{"title":"High-speed transfer of two 4 KV motor bus sources using a digital motor bus transfer system","authors":"G. T. Orr, S. Cooper, C. Mozina","doi":"10.1109/ICPS.2010.5489883","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489883","url":null,"abstract":"At many industrial facilities, distribution busses serving critical loads are supplied from two power sources. Typically, this bus arrangement is in a main-tie-main arrangement. Upon the loss of the normal power source, critical motor loads must be transferred to the alternate source without damaging the equipment, and ideally, without interrupting the process. In this application, two digital motor bus transfer systems were installed to transfer two 4 KV busses to two sources. This paper describes the steps to applying a digital motor bus transfer system to medium-voltage switchgear at a large chemical company including the feasibility analysis, available transfer methods, input/output considerations, settings, and commissioning methods. A summary of actual operations data to date and lessons learned is also included.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133890858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489895
R. Rifaat
Usage of 3-winding transformers is extended to industrial and in-plant generation in order to realize cost and real estate savings. Such an extension has been successful in most cases. However in some cases, better understanding of how to size, specify test requirements, and model the 3-winding transformers for power system studies, would have avoided unnecessary electrical distribution system sub-performance. As equipment with inherit systems the subject transformers performed as intended. The successes and short comings are attributed to the interpretations of the 3-winding transformer parameters as part of the larger industrial power system. Hence, it is essential to scrutinize the modeling, selection of case studies, scenarios, analysis of study results and system design when 3-winding transformers are used. From application experiences this paper addresses concerns associated with the selection of 3-winding transformers discusses power system sensitivity to their parameters and presents the scenarios, cases and modeling accuracies required for associated industrial system studies.
{"title":"Considerations in modeling and applications of three winding transformers in industrial and commercial facilities","authors":"R. Rifaat","doi":"10.1109/ICPS.2010.5489895","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489895","url":null,"abstract":"Usage of 3-winding transformers is extended to industrial and in-plant generation in order to realize cost and real estate savings. Such an extension has been successful in most cases. However in some cases, better understanding of how to size, specify test requirements, and model the 3-winding transformers for power system studies, would have avoided unnecessary electrical distribution system sub-performance. As equipment with inherit systems the subject transformers performed as intended. The successes and short comings are attributed to the interpretations of the 3-winding transformer parameters as part of the larger industrial power system. Hence, it is essential to scrutinize the modeling, selection of case studies, scenarios, analysis of study results and system design when 3-winding transformers are used. From application experiences this paper addresses concerns associated with the selection of 3-winding transformers discusses power system sensitivity to their parameters and presents the scenarios, cases and modeling accuracies required for associated industrial system studies.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133985327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-09DOI: 10.1109/ICPS.2010.5489909
W. Brown, J. M. Kennedy, C. Linkhart
The paralleling of uninterruptible power supplies (UPS's) with generators during UPS bypass operations can result in high-magnitude circulating ground currents under certain conditions. This paper explores the phenomena that cause this system behavior, presents data from an actual documented occurrence, and discusses methods to reduce or eliminate such circulating currents.
{"title":"Investigation of circulating ground currents occurring during UPS/generator paralleling","authors":"W. Brown, J. M. Kennedy, C. Linkhart","doi":"10.1109/ICPS.2010.5489909","DOIUrl":"https://doi.org/10.1109/ICPS.2010.5489909","url":null,"abstract":"The paralleling of uninterruptible power supplies (UPS's) with generators during UPS bypass operations can result in high-magnitude circulating ground currents under certain conditions. This paper explores the phenomena that cause this system behavior, presents data from an actual documented occurrence, and discusses methods to reduce or eliminate such circulating currents.","PeriodicalId":346769,"journal":{"name":"2010 IEEE Industrial and Commercial Power Systems Technical Conference - Conference Record","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125270104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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