{"title":"Cable temperature requirements and fault current detection in telephone equipment locations","authors":"J. Godby, L. Hinkel","doi":"10.1109/INTLEC.1990.171262","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171262","url":null,"abstract":"The problem of the inability of overcurrent protection devices to operate consistently in telephone switching equipment locations is addressed. Overcurrent protection (fuses or circuit breakers) will not always function with DC power to ground faults in the major power feeders because of the design philosophies of the power feeders and their associated overcurrent protection devices. Sizing principles of the power feeders from the battery plant to the secondary DC power distribution are listed, and the issues of cable temperatures and fault current detection are discussed. Fault current monitor considerations, including the description of microprocessor-controlled power monitor and control systems (MPMCs) are presented.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127597003","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}
{"title":"Intelligent power management and control-a maintenance view","authors":"B.I. Wallner, R. Bowers","doi":"10.1109/INTLEC.1990.171289","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171289","url":null,"abstract":"The requirements and application of intelligence power monitoring and control (IPMC) for power systems in central office, CDO and remote/radio sites are described from a field maintenance point of view. The IPMC system is designed to provide the same degree of power management and control of power systems that is currently provided for switching and transmission facilities. The system is an onsite, processor-based system that automatically performs surveillance data collection, testing, on/off line analysis and control of all components of central office power plants. This control includes emergency generators, UPS (uninterruptible power supply) systems, and AC switchgear. Because of its open architecture, the intelligent power system at one trial site also includes security (door card reader and perimeter) monitoring as well as fire escalation calls. The IPMC will extend power expertise for maintenance and reinforce the power reporting capability by directing help calls to key power personnel.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133623870","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}
{"title":"A new decentralized DC power system for telecommunications systems","authors":"K. Mizuguchi, S. Muroyama, Y. Kuwata, Y. Ohashi","doi":"10.1109/INTLEC.1990.171225","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171225","url":null,"abstract":"A new decentralized power system has been developed to decrease the cost and the floor space requirements of the conventional decentralized power system now used by NTT. The new system is composed of rectifiers, booster converters, and batteries. The maximum output current of the system is 1000 A at the output voltage of 48 V DC. It can decrease annual cost by about 20% for power equipment, construction and electricity. Additionally the floor space required for power equipment in telecommunications rooms is reduced about 30%. The authors describe the configuration and operation of the new system, and review evaluation results for the annual cost and floor space of this system compared with conventional system.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131834692","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}
{"title":"Increased float voltage and the effects of negative self-discharge on flooded lead calcium telecommunications cells","authors":"T.G. Martinez, A. Novak","doi":"10.1109/INTLEC.1990.171253","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171253","url":null,"abstract":"The problem of negative plate self-discharge in flooded lead-calcium cells is addressed. Two aspects of the problem are discussed. The first is quantification of negative plate self-discharge through recharge testing. The second is the benefits and drawbacks of equalizing the cells by the method of increasing the float voltage from 2.17 to 2.20 Vpc. Float operation, temperature effects, and polarization calculations are also discussed.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124141047","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}
{"title":"ENTEL Bolivia microwave network powered by photovoltaic/diesel hybrid power systems","authors":"C. Coleman","doi":"10.1109/INTLEC.1990.171293","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171293","url":null,"abstract":"Northern Power Systems (NPS) supplied fourteen photovoltaic/diesel hybrid power systems to the Bolivian national telecommunications company, ENTEL. These power systems were supplied under contract with AT&T World Services, the prime contractor for the microwave link. The author describes the basic design philosophy, components and hardware configurations, training issues, and experiences with installation and commissioning. The use of photovoltaic/diesel hybrid power systems for this remote microwave project has proved to be economical and technologically successful. The major obstacles to the project were experienced not with the hybrid system technology but in the logistics and material handling portions of the project.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114767149","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}
{"title":"Identification and thermal simulation in building industry","authors":"C. Archambault, T. Le Magueresse","doi":"10.1109/INTLEC.1990.171247","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171247","url":null,"abstract":"The ISIBAT software (the acronym comes from the French for 'Building Identification and Simulation') was created at the France Telecom Research Center (CNET) in cooperation with the University of Brest. It is intended to identify and simulate the thermal behaviour of buildings housing any telecommunications equipment, but its fields of application are not limited to the thermal kinetics of building. Three examples are given to illustrate the performance of ISIBAT. The first concerns the design of outdoor distribution frame cabinets housing subscriber line equipment in which no heat dissipation occurs. The second is the analysis of a small remote telephone exchange with a heat dissipation below 2 kW, housed in a 10 m/sup 2/ building in a rural area. The third concerns a large exchange with a heat dissipation exceeding 10 kW installed in a 130 m/sup 2/ air-conditioned room. The results obtained in these three cases using ISIBAT are compared with those obtained using different evaluation methods.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114845954","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}
{"title":"Unregulated temperature excursions in VRLA standby battery enclosures","authors":"R. Nelson","doi":"10.1109/INTLEC.1990.171243","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171243","url":null,"abstract":"Laboratory testing on valve regulated lead-acid (VRLA) batteries under conditions designed to accelerate failure lead to life predictions that are inconsistent with results seen in actual field applications. In most standby battery enclosures, units experience elevated temperatures and thermal cycling not encountered in laboratory experiments. This study includes a qualitative thermal model for such cabinet enclosures, and it is shown that batteries operate under conditions that do not accurately reflect the surrounding environment. In most cases, overheating of batteries leads to shortened life; in extreme cases systems can go into catastrophic thermal runaway, resulting in total system failure. Thermal runaway is defined in practical terms, and results of experimental studies are presented that point toward the source of this phenomenon.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129768510","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}
{"title":"Will distributed on-board DC/DC converters become economically beneficial in telecom switching equipment?","authors":"L. Thorsell","doi":"10.1109/INTLEC.1990.171226","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171226","url":null,"abstract":"The author considers different power distribution systems for telephone switching equipment. Described are central distribution, decentralized distribution with one converter per shelf, and decentralized distribution with distributed on-board supplies. Besides a choice between a more central type of power supply and a distributed architecture, there is also a choice of whether the design shall be of an internal or external nature. The situation is examined, and some key figures are estimated that can be used when choosing which way to go.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128972376","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}
{"title":"The use of phase change materials (PCMs) and vacuum panel heat exchangers for energy conservation and thermal stability of electronic equipment enclosures","authors":"R. Prudhoe, L. Doukas","doi":"10.1109/INTLEC.1990.171246","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171246","url":null,"abstract":"Advances in the development and application of new types of energy conservation systems and control devices to achieve thermal stability of electronic equipment enclosures are addressed. Phase change material (PCM) research conducted to find new types of self temperature regulating, energy conserving high-density thermal energy storage structures is described. Such systems have become the standard method of reserve cooling in smaller type telephone exchanges with PCM application now extending into larger type exchanges. Also introduced is a vacuum panel heat exchanger (VPHE) currently being developed in Australia. The VPHE is a superconductor of heat which will enable the building to behave as a thermal diode heat pipe. The authors conclude with a discussion of some novel design concepts which they believe will form the basis for future developments in communication equipment buildings that will be more in tune with natural energies and protection of the natural environment.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132416470","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}
{"title":"A three element fuse that can be triggered 'open' in the event of fire","authors":"M. Wolpow, R. Ludlow","doi":"10.1109/INTLEC.1990.171264","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171264","url":null,"abstract":"A simple, safe, inexpensive and exact method is described for disconnecting the bus conduits from the battery strings in the event of fire or catastrophe by means of a fuse that can be triggered open. The trigger open, self-destruct link is essentially a melt system derived from a self contained oxidizable chemical package. This is achieved by means of an ultrafine aluminothermic slow alloy emulsion that is soft-sintered on to each side of the zinc alloy fuse link. An ultrafine magnesium alloy ignitor is embedded into the emulsion surface. The ignitor can be commanded to turn on by the electronic package, causing the emulsion to burn 'easy' and melt the link. This entire discrete link is ceramic encapsulated; therefore, it does not pose any fire threat. It is also further embedded into extinguishing sand.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130900661","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}