Electricidad - 651 entradas encontradas
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German Standards Committee (Deutscher Normenausschuss), Berlin (Westsektoren); German Electrotechnical Commission (Deutscher Elektrotechnische Kommission), Frankfurt am Main, May 1975.
Rule of the Association of German Electrical Engineers concerning the operation of power installations
VDE-Bestimmung für den Betrieb von Starkstromanlagen [en alemán]
This rule applies to the operation of electrical installations in conformity with regulations VDE 0100 and 101 (rated voltage below and above 1kV respectively). It also applies to construction, assembly and repair work carried out in the vicinity of heavy current installations. Definitions and general requirements are followed by provisions concerning the following points: operation of electrical installations, maintenance and cleaning; disconnection before all interventions, and checks to ensure that the installation is "dead"; switching on after conclusion of the work; "hot" work; work near live installations; equipment for prevention of accidents and fire fighting equipment.
Beuth Verlag GmbH, Burggrafenstrasse 4-7, 1 Berlin 30. 38p. Illus. Price: DM.21.00.
Stuurgroep Richtlijnen Veiligheid Procesindustrie, Voorburg.
Dangers of static electricity in the process industry
Gevaren van statische elektriciteit in de procesindustrie [en holandés]
Report drawn up by a Dutch committee set up to draft safety directives. Contents: causes and hazards of static electricity charges; selection of types of flooring, footwear and clothing; conductivity of liquids; speeds of liquid transfer; hazards of suspending or dispersing substances in liquids; earthing when loading or unloading tanker trailers and trucks; transfer of gases; prevention of dust explosions (ignition energy, particle size, concentration); rules for earthing. Characteristic values and measurements of electrical resistance are appended.
Directoraat-Generaal van de Arbeid, Postbus 69, Voorburg, Netherlands, 1975, 57p. Illus. 59 ref. Price: Glds.2.50.
Notes on the convention on electrical installations at construction sites
A propos de la convention relative aux installations électriques de chantier. [en francés]
On construction sites, the solution requiring each undertaking and each trade to provide a statutory installation cannot be applied. Thus the Organisation for Safety in Building Construction and Civil Engineering (Organisme professionnel de prévention du bâtiment et des travaux publics) in France has attempted to promote the setting up of a provisional collective installation by a specialist (generally the electrician responsible for installing the electricity in the building) on the basis of a convention that architects have accepted to include in their specifications when inviting tenders. The convention eliminates certain electrical hazards, promotes order, limits the number of cables, which are a cause of falls, and ensures correct lighting of communication ways. It further increases the efficiency of the site by facilitating detection of failures and improving operation conditions. The main aspects are illustrated by photographs taken on a work site, with comments.
Cahiers des Comités de prévention du bâtiment et des travaux publics, Mar.-Apr. 1975, No.2, p.67-71. Illus.
Gabor S., Frits T., Anca Z.
Effect of quartz and asbestos on erythrocyte surface charge.
Method and results of experiments in vitro, carried out to determine the surface-charge density of human red cells incubated with 7 quartz varieties and UICC asbestos dusts. Red-cell mobility was measured by capillary migration on Whatman paper strips and by electrophoresis. All dusts significantly decreased the erythrocyte surface electric charge, possibly as a result of activation of neuraminidase induced by quartz and asbestos. Pretreatment of quartz dust with polyvinylpyridine-N-oxide restored the electronegativity of erythrocytes. The results support the theory of the cytotoxic effect of quartz and asbestos on the external cell membrane.
International Archives of Occupational and Environmental Health, 4 Nov. 1975, Vol.36, No.1, p.47-55. Illus. 21 ref.
Electrical safety in compact high-tension switching stations
La sécurité électrique dans les postes à haute tension à encombrement réduit. [en francés]
A relatively recent technique used in the installation of high voltage switchgear is described, in which all components are encased in a metal enclosure filled with gas under pressure (usually sulfur hexafluoride) which acts as a dielectric. The article describes how extension, maintenance and repair work can be carried out in safety on these installations. The procedure is illustrated by 2 examples (replacement of a changeover isolating switch, replacement of a busbar section), with circuit diagrams. No interruption of normal operation of the system is required, and yet all contact with live elements is avoided.
Vigilance, 1975, No.51, p.15-20. Illus.
Rain-proof insulating rods for work with rated voltages up to 110kV
Regensichere Betätigungsstangen mit Nennspannungen bis 110kV [en alemán]
Presentation of insulating rods offering protection during work in the rain with voltages of 30, 60 and 110kV: properties required, testing, design, materials employed, electrical and mechanical characteristics. The rods consist of a tube of fibrous-glass-reinforced epoxy resin filled with polyurethane foam. The outer casing of the rods and the umbrella discs are composed of silicon rubber. The number of discs varies according to the voltage: 2 for 30kV, 3 for 60kV, and 4 for 110kV.
Sichere Arbeit, 1975, Vol.28, No.2, p.11-14, 22. Illus.
Construction sites and electric current
Die Baustelle und der elektrische Strom [en alemán]
After some general remarks concerning electrical accidents (direct and indirect contacts, effects of electric current on the human body, dangerous current) this article gives general accident statistics in the building and civil engineering sector for the period 1968-1972, showing that electrical accidents are comparatively rare, but that the probability of their being fatal is 27 times greater than in the case of other types of accident. The author deals in particular with the following points: regulations of the Association of German Electrical Engineers, distribution panels on construction sites, protection against electrical hazards, connectors and conductors, protection of lamps and other electrical equipment and prevention of direct contacts with electrical installations or overhead power lines.
Die Industrie der Steine und Erden, Mar.-Apr. 1975, Vol.85, No.2, p.40-47. Illus.
Zabudkin I.L., Žilo V.N.
Instrument for measuring static electricity accumulated during the mechanised loading of boreholes
Pribor dlja izmerenija stepeni ėlektrizacii pri mehanizirovannom zarjažanii skvažin [en ruso]
Considerable charges of static electricity may build up during the pneumatic loading of boreholes with loose explosives. To measure these charges, which might cause premature initiation, an instrument has been developed which, without contact, quantifies and indicates the potential of the electrostatic charge in kV. Detailed description of the instrument and its use.
Bezopasnost' truda v promyšlennosti, Dec. 1974, No.12, p.47-48. Illus.
Hazard evaluation of the discharge of static electricity from the human body in chemical production areas with explosive atmospheres
Opredelenie stepeni opasnosti razrjadov statičeskogo ėlektričestva s tela čeloveka vo vzryvoopasnyh proizvodstvah himičeskoj promyšlennosti [en ruso]
Results of human experiments undertaken to determine the relations between (1) the electrical capacitance of the body and (2) the height of the body and the type of floor-covering material. Man senses an accumulation of static charges when they have reached 25kV. Determination of the maximum safe potential for the human body in relation to the minimum energy required to ignite a gaseous mixture showed that the energy of a static discharge coming from the body is enough to ignite all gas-air or vapour-air mixtures and some dust-air mixtures. This hazard can be calculated by an equation, which is given.
Himičeskaja promyšlennost', Nov. 1974, No.11, p.825-827. Illus. 11 ref.
Treatment of extraneous electricity in electric blasting.
This data sheet concerns procedures needed to minimise stray current hazards, and personal injury due to these hazards, during blasting operations. Sections are devoted to: hazards from extraneous electricity (stray currents, sources of stray currents; electric blasting caps; detecting and minimising stray currents and protection from these currents; lightning, static electricity, radio frequency energy). Information on electrical systems is appended.
Data Sheet 644, National Safety Council, 425 North Michigan Avenue, Chicago, Illinois 60611, USA, 1974. 8p. Illus. 4 ref.
Panova Ju.M., Ivanova I.G.
Cardiovascular changes due to electric burns
Izmenenija serdečno-sosudistoj sistemy pri ėlektroožogah [en ruso]
Results of clinical observations of 140 patients with electric contact burns. Disorders of the cardiovascular system were characteristic in the case of high-voltage burns. The authors frequently observed an atrioventricular extrasystole and disturbances of the atrioventricular rhythm. An outstanding feature was the existence of neuro-circulatory disorders accompanied by fits of paroxysmal tachycardia, a significant rise in arterial pressure, disturbed myocardial circulation in and disorders of the central nervous system. All these disorders are persistent and recovery is a long-term process.
Sovetskaja medicina, May 1974, No.5, p.58-63. Illus. 19 ref.
Safe work with portable electric tools
Veilig werken met elektrisch handgereedschap [en holandés]
Descriptions of fatal accidents (due to confusion of the earth conductor during the renewal of a flexible cord, substitution of stones for a safety isolating transformer in the transformer box) are followed by comments on the Netherlands safety legislation respecting extra-low voltage, double insulation, high-frequency tools and off-the-job electrical equipment. Attention is drawn to limitations of certain safety principles (e.g. double insulated tools should not be used in tanks and confined spaces). Rules for safe working methods are given (safety checks, correct use, work in hazardous premises, personal protection).
De veiligheid, Dec. 1974, Vol.50, No.12, p.489-495. Illus.
Les surtensions. [en francés]
In this article, which is concerned only with continuous overvoltages in an electric network, i.e. at the frequency of the network, examples are presented to show that such overvoltages can be prevented by appropriate design of equipment. The best solution may be to avoid 2 different voltages in the same network; this can be done in a variety of ways: not laying a neutral conductor; using transformers with separate windings rather than autotransformers; not employing the 2 transformer sockets (220 and 380V), when present, simultaneously. With regard to protection against overvoltage originating in high-voltage installations, the best solution (interbonding of the earth connections) coincides with the best means of personal protection against electrocution as a result of indirect contacts.
Promotion de la prévention, 4th quarter 1974, No.32, p.22-37. Illus.
Protective measures against excessive contact voltage (in the light of directive 0100/5.73 of the Association of German Electrical Engineers)
Schutzmassnahmen gegen zu hohe Berührungsspannung (in Anlehnung an VDE 0100/5.73) [en alemán]
Explanation of fault voltage, contact voltage, earth-leakage voltage, and commentary on the provisions of directive VDE 0100/5.73 of the Association of German Electrical Engineers: double insulation, very low safety voltage, supply by isolating transformer, connection to neutral, direct earthing, protective conductors, fault-current-operated and fault-voltage-operated relays, protection against overvoltage, state of insulation of electrical plant, installation of earth electrodes and earth conductors, checks of safety and insulation, safety measures at construction sites and in agricultural establishments.
Nr.9, VDE-Schriftenreihe, VDE-Verlag GmbH, Bismarckstrasse 33, 1 Berlin 12 (Westsektoren), 1974. 97p. Illus. 16 ref. Price: DM.10.00.
High-voltage electrical installations - Regulations
Installations électriques à haute tension - Règles. [en francés]
Rules for electric installations supplied with alternating current at a rated voltage of 1,000V to 66kV (frequencies below 10kHz). Definitions, specifications for the design of installations (with diagrams) and environmental conditions (degree of protection of sheathing, atmospheric influences and pollutants, fire and explosion hazards), rules for electrical safety (protection against electric shock, effects of heat, overcurrent, overvoltage), rules for the choice and use of equipment, and provisions concerning premises or sites intended for installation of electric equipment.
Norme française enregistrée NF C 13-200, French Electrotechnical Association (Union technique de l'Electricité), 12 place des Etats-Unis, 75783 Paris Cedex 16, France, Dec. 1974. 48p. Illus.
Llaurado J.G., Sances A., Battocletti J.H.
Biologic and clinical effects of low-frequency magnetic and electric fields.
This book presents the papers, discussions and reports from a symposium and workshop held in Aspen, Colorado (USA) on 18-24 Feb. 1973, sponsored by the U.S. National Science Foundation in concert with other societies and university colleges. The first 4 sections contain papers and discussions on: Sources and effects of electric and magnetic fields on biological systems (General; Special topics); Electrical stimulation and therapy; Nuclear magnetic resonance applications. The 5th section comprises 4 workshop reports: Magnetic-electric fields and environments; Sources and safe levels of electric and magnetic fields; Biological effects of electric currents: electrical stimulation and therapy; Magnetics and nuclear magnetic resonance. Index.
Published by Charles C. Thomas, 301-327 East Lawrence Avenue, Springfield, Illinois, USA, 1974. 345p. Illus. 446 ref. Price: US-$34.50.
Development trends in international research in the field of electrical safety
Internationale Entwicklungstendenzen auf dem Gebiet der Elektrosicherheit [en alemán]
Panorama of the institutions in Western and Eastern Europe (including the USSR) engaged in research in the field of electrical safety, giving the subjects of research, with 2 summary tables. General development trends in international research apparent from analysis of technical literature.
Der Elektro-Praktiker, 1974, Vol.28, No.5, p.148-151. 10 ref.
Resistivity problems in electrostatic precipitation.
Comprehensive and up-to-date description of the problems encountered in the collection of high-resistivity particles by electrostatic precipitation. Subjects dealt with include: measurement of resistivity, resistivity data (chemical powders, industrial dusts and fumes), electrical conduction mechanisms, effects of high resistivity on precipitation performance, and methods of overcoming high resistivity (wet methods, etc.).
Journal of the Air Pollution Control Association, Apr. 1974, Vol.24, No.4, p.313-338. Illus. 51 ref.
Live work at the French Electricity Board - Research at SERECT
Les travaux sous tension à Electricité de France - Les recherches à la SERECT. [en francés]
The Study, Development and Experimentation Section of the Committee on Live Work (Section d'études, des réalisations et d'expérimentation du Comité des travaux sous tension - SERECT) was created by the French Electricity Board. Description of its activities, which relate to the development of new methods and tools, particularly for work on live low-voltage networks (special clothing, insulating blankets for network installations, equipment for fitting splicing sleeves) and medium-voltage networks (extension of remote working to 30kV networks, work on small-section conductors, hydraulic tools, earth-boring and pole-lifting equipment, aerial baskets).
Vigilance, Feb. 1974, No.48, p.3-13. Illus.
Jacobsen J., Buntenkötter S., Schreyer L.
Hazard ranges of electric currents
Gefährdungsbereiche elektrischer Ströme [en alemán]
Results of experiments with pigs to determine the mean hazardous current intensity for ventricular fibrillation are discussed. The minimum current intensity, being fatal under worst-case conditions, and the dangerous values of different current types are indicated. The heart-current factor, which allows for the amount of current flowing through the heart, depends on the current path in the body; values for this factor are tabulated. The effects of an electrical accident are subdivided into 3 classes in relation to the intensity and resistance of the total circuit. Finally, the safe ranges of a current-operated earth leakage circuit breaker with 30mA rated leakage current are dealt with.
etz - Elektrotechnik + Automation, Ausgabe B, Berlin (Westsektoren), 1974, Vol.26, No.12, p.321-325. Illus. 8 ref.
Iinoya K., Makino K.
Application of electric field effects to dust collection filters.
New types of electric fibrous dust filters (a fibrous filter packed with electrically conductive graphite fibres and a dielectric fibrous filter) are discussed analytically and experimentally. The electric field effect on collection efficiency is remarkable. In comparison with conventional fibrous filters, higher efficiency can be achieved with lower pressure drop for the new types.
Aerosol Science, Aug. 1974, Vol.5, No.4, p.357-372. Illus. 24 ref.
Degree of protection with connection to neutral by a separate protective conductor and with classic connection to neutral
Schutzwert der Nullung mit besonderem Schutzleiter gegenüber der klassischen Nullung [en alemán]
Statistical bases of this evaluation and history of connection to neutral by (1) local connection of the non-current-carrying parts to the neutral conductor and (2) by the intermediary of a separate protective conductor, made compulsory in the German Federal Republic in 1970. Statistical analysis of 860 fatal electrical accidents, and calculation of the degree of protection. The low degree of protection assured by connecting to neutral by means of a separate conductor backs up the misgivings of experts concerning the general use of this system. Study of the technical reasons for this poor efficacity.
Forschungsbericht Nr.119, Bundesanstalt für Arbeitsschutz und Unfallforschung, Martener Strasse 435, 46 Dortmund-Marten, Germany (Fed.Rep.), 1974. 81p. Illus. 47 ref. Price: DM.10.50.
Ministry of Labour (Ministère du travail), Paris.
Order of 7 Aug. 1974 extending the general regulations relating to the prevention of occupational accidents in the course of electrical work
Arrêté du 7 août 1974 portant extension des dispositions générales concernant la prévention des accidents du travail lors des travaux électriques. [en francés]
The general regulations enacted by the South-East France Regional Sickness Fund (Caisse régionale d'assurance maladie du Sud-Est de la France), annexed to this order, are extended to the whole of the French territory. They make it compulsory for heads of undertakings to comply with the provisions of the publication UTS 18-513 concerning the construction, operation and maintenance of electricity distribution networks (CIS 72-1783), which are commented upon.
Journal officiel de la République française, 20 Aug. 1974, Vol.106, No.194, p.8645-8646.
Safe working methods in electric welding
Sicherheit beim Elektroschweissen [en alemán]
The author recalls the risks of electrical accident and the effects of electric current on the human body, and examines the factors giving rise to these hazards (power supply, cables, electrode holders). Hazards connected with UV radiation and preventive measures (protective lenses, screening of welding unit, protective clothing). Protection against welding fumes and gases, fire and explosion.
Hochbau, July-Aug. 1974, Vol.62, No.4, p.106-109. Illus. 6 ref.
High-voltage insulation-enclosed switchgear and controlgear.
Appareillage à haute tension sous enveloppe isolante [en francés]
This recommendation deals with switchgear and controlgear for alternating current of rated voltages from 1 to 38kV for indoor installations. Definitions of technical terms are followed by provisions concerning service conditions, ratings, the degree of protection against dangerous electrical effects when touching the enclosure, design and construction, and tests. Supplementary information on the tests is appended.
Publication 466, International Electrotechnical Commission, l rue de Varembé, 1211 Genève 20, Switzerland, 1974. 68p. Price: SF.70.00.
Effects of current passing through the human body.
Rapport sur les effets du courant électrique passant par le corps [en francés]
This report, based on an extensive literature survey and the evaluation of answers to a questionnaire survey, outlines the present knowledge of the physiopathological effects of sinusoidal alternating currents and direct currents on adults. Diagrams present the time/current zones for a.c. 50/60Hz and d.c. and illustrate the influence of frequency. Resistance of the human body and experience with voltages not exceeding 50V a.c. or 75V d.c. are also discussed.
Publication 479, International Electrotechnical Commission, 1, rue de Varembé, 1211 Genève 20, Switzerland, 1974. 10p. Price: SF.14.00.
The effects of electric current on man
Les effets du courant électrique sur l'homme. [en francés]
This study, based on a statistical analysis of the effects of electric currents on animals and man, was undertaken with a view to increasing the safety of hospital patients rendered more susceptible even to very low intensities. It is also of interest to users of electrical apparatus, showing as it does that even a current of very low intensity is not without risk, depending on the duration of its passage through the body and its path.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 2nd quarter 1974, No.75, Note No.898-75-74, p.229-234. Illus. 1 ref.
Personal protective equipment for work on electric installations
Persönliche Schutzausrüstungen für Arbeiten an elektrischen Anlagen [en alemán]
The equipment described is designed both to prevent the passage of electric current through the body and to afford protection against the thermal effects and flying particles resulting from an electric arc. Detailed discussion of the equipment to be worn for low voltage (gloves, helmet, face shield and protective clothing, insulating blankets or sections) and high voltage (insulating screens).
Die Berufsgenossenschaft, Apr. 1974, No.4, p.149-155. Illus.
Protection against the risk of contact between the bucket of a power shovel and the trolley wire of railways in opencast mines
O zaščite ot opasnyh posledstvij kasanija kovšom ėkskavatora kontaktnogo provoda ėlektrificirovannogo transporta na kar'erah [en ruso]
The author reviews the different means of preventing contact between power shovels and trolley wires in opencast mines served by railway connections, and of limiting the consequences of such contact. After weighing the advantages and disadvantages of these means, he gives preference to frequency multiplier protection and input of an alternating current of 150Hz into the network, a solution suitable for mass production of the requisite frequency multipliers.
Bezopasnost' truda v promyšlennosti, Mar. 1974, No.3, p.46-47.
Corbett R.P., Hughes J.F.
Second part of an inset data sheet on electrostatics (the first part deals with benefits). Considerations on electrostatic discharges in non-incendive atmospheres and means of removing charges (a.c. corona source neutraliser) are followed by a chapter on electrostatic hazards in incendive atmospheres (aircraft refuelling, tank cleaning). To overcome the charge separation taking place during tank filling, the use of antistatic additives (which simply increase the conductivity of the fuel) has proved successful. The simplest and safest way to combat electrostatic hazards in large fuel tanks is inerting the tank atmosphere with waste flue gases from tanker boilers. 2 simple rules for the reduction of electrostatic charging are given: for liquids, reduce or eliminate all traces of water; for solids, add water or increase relative humidity.
Engineering, July 1974, Vol.214, No.7, p.v-viii (Technical file No.7). Illus.
Portable earthing devices
Ortsveränderliche Erdungsgarnituren [en alemán]
Earthing and short-circuiting devices for overhead lines are presented as the most effective method of preventing electrical accidents. Features and instructions for use of auxiliary equipment: insulating rods, phase conductor earthing connections, short-circuiting and earthing cables. Results of manufacturers' tests with short-circuiting and earthing equipment. Solutions to problems of detail: short-circuiting bridges, locking of earthing devices, provision of connection points, recent advances.
Technische Rundschau, 22 Jan. 1974, Vol.66, No.3, p.38-41, and 12 Feb. 1974, Vol.66, No.6, p.27-31. Illus. 5 ref.
Sequelae of electrical accidents
Folgen elektrischer Unfälle [en alemán]
Evaluation of 10,000 electrical accidents which occurred between 1967 and 1970, taken from medical case histories compiled by practitioners appointed by the Mutual Accident Insurance Association for the Precision Engineering and Electrical Equipment Manufacturing Industry. The first part describes the method followed in carrying out the survey and the statistical results obtained, classified according to age of injured person, cause of accident (voltage intensity), clinical sequelae (general condition, surgical, cardiac, haematological and neurological sequelae, fatal outcome) and treatment given. The second part contains a discussion of these results, referring to the conclusions of several other statistical studies. The following relations are stressed: the accident frequency rate diminishes with age, but the severity rate increases; accidents caused by high-voltage alternating current had the most serious physical and psychic consequences; there were 3 deaths due to direct current. No significant relationship between cardiac injury and age was discovered.
Medizinischer Bericht 1973, Institut zur Erforschung elektrischer Unfälle bei der Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Oberländer Ufer 130, 5 Köln-Bayenthal, Germany (Fed.Rep.), 1974. 87p. Illus. 81 ref.
Firefighting equipment and extinguishing methods used in fighting fires in electrical installations
Engins d'extinction et moyens d'extinction pour la lutte contre le feu dans des installations électriques [en alemán]
Engins d'extinction et moyens d'extinction pour la lutte contre le feu dans les installations électriques. [en francés]
Description of the firefighting properties of extinguishing agents such as water, foam, powders, CO2 and halogenated hydrocarbons. Examines a number of portable extinguishers and wheeled firefighting equipment, and the circumstances in which they can be used.
Bulletin des Schweizerischen elektrotechnischen Vereins - Bulletin de l'Association suisse des électriciens, 23 Feb. 1974, Vol.65, No.4, p.256-263.
Bibliographical study relating to electropathology - Vol.2.
Etude bibliographique concernant l'électropathologie - Tome 2 [en francés]
Second compendium of work published in France and other countries, comprising over 1,000 references classified under the following headings: physical characteristics of electrical accidents and conditions conducive to electrocution; prevention; physiopathology, experimentation, histology; instantaneous death; loss of consciousness, resuscitation; injuries due to electric current, complications, sequelae; social after-effects, rehabilitation, absence from work, incapacity for work, expert testimony; miscellaneous. The first compendium, published in 1968, listed work published up to 1965. The majority of the references given in this new compilation are recent ones.
International Union of Producers and Distributors of Electrical Energy, Medical Study Group, 30 avenue de Wagram, 75008 Paris, France, 1974. 72p.
Safe electrical installations
La sécurité des installations électriques. [en francés]
Translation of: Sichere elektrische Anlagen. Sicherheitsingenieur, Heidelberg, Germany (Fed.Rep.), 10 Sep. 1971, Vol.2, No.9, p.32-39. Illus. After stressing the need for all factors affecting safety to be taken into account during the planning and design of electrical installations, the author reviews the various hazards of electrical accidents (contact voltages, live components, arcing) and considers appropriate protective measures. He then deals in turn with each of the 5 fundamental safety rules (use of all-pole switches, protection against premature re-connection, checking that equipment is dead, earthing and short-circuiting protection, enclosure of certain live parts in the immediate proximity of the operator).
Traduction INRS 82 B-73, Institut national de recherche et de sécurité, 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, 1973. 19p. Illus.
Dörr G., Preisedanz H.
Recent work on electrostatic charge in oxygen lances
Neuere Untersuchungen über elektrostatische Aufladungen in Sauerstofflanzen [en alemán]
Since fires and explosions often occur in oxygen lances and piping which cannot be attributed to normal causes, the possibility that static electricity could accumulate during the injection of oxygen into steel-making furnaces was investigated. The presence of humidity and solid particles in the oxygen is considered to be a possible causal factor. The results of tests carried out on an experimental plant show that, in the conditions given, the accumulation of static electricity can be expected.
Heft 17, Moderne Unfallverhütung, Vulkan-Verlag, Haus der Technik, 43 Essen, Germany (Fed.Rep.), 1973. p.16-22. Illus. 10 ref.
Meda E., Carrescia V., Cappa S.
Some experimental results of exposure to strong 50Hz electric fields
Alcuni risultati sperimentali sull'esposizione ad intensi campi elettrici a 50Hz [en italiano]
The normal environment for man becomes altered in the vincinity of electric lines, where the potential gradient of a 50Hz electric field may reach very high values. Linemen working on live line maintenance are subject to even stronger electric fields. This article describes initial experimental research on this question, carried out on mice, rats and guinea pigs exposed to a 50Hz, 1kV/m electric field, which disclosed ECG, EEG and leucocyte count changes. These investigatins should be pursued with increased resources on a sufficiently large number of humans.
Securitas, 1973, Vol.58, No.7, p.685-700. Illus. 6 ref.
Malboysson E., Bonell A.
Estado psicosomático y psicológico del accidentado
Results of a psychological survey conducted by means of the Pinillos personality questionnaire and personal interviews with 2,127 workers who had electrical accidents in the electrotechnical industry, divided into 2 groups according to the cause of the accident sustained: exposure to an electric arc or current passing through the body. Several of the cases studied are described. The survey disclosed that electrical accidents have the peculiar effect of leading to personality and behavioural changes independent of the severity of the accident and unrelated to its sequelae.
Medicina y seguridad del trabajo, Jan.-Mar. 1973, Vol.21, No.81, p.19-25.
Efecto "PAT" en subestaciones eléctricas
Describes a syndrome, which the author calls the "HVS effect" (high-voltage substation), which affects persons working at substations where very high-voltage current is transformed and which disappears shortly after the end of the exposure. It is characterised by a feeling of tightness and oppression affecting the head, laxity and fatigue in the upper extremities and persistent insomnia; electroencephalograms show signs of cerebral pain.
Medicina y seguridad del trabajo, Jan.-Mar. 1973, Vol.21, No.81, p.15-18.
Constuction principles for modern medium-voltage switching stations
Principes de la construction des installations modernes de couplage à moyenne tension. [en francés]
The different types of construction of medium-voltage (up to 36kV) electrical plant are reviewed. In order to increase personal and operational safety, mechanical measures should be taken (frontal protection of switching compartments by glass-panelled doors, clamping into place of the draw-out trucks, partitioning within the compartments) and electrical safety measures (partial insulation of the busbar system, resistance of the compartment to arcing).
Bulletin des Schweizerischen elektrotechnischen Vereins - Bulletin de l'Association suisse des électriciens, 17 Feb. 1973, Vol.64, No.4, p.252-258. Illus.
Construction principles for switching stations to ensure optimal safety of personnel
Principes de construction des installations de couplage en vue d'obtenir une sécurité de travail optimale. [en francés]
Safety measures to protect against electric contact during the operation of, and work in, high-voltage switching stations are reviewed, including: transparent screens made of hardened glass, locking of tripped circuit-breakers, ergonomic design of equipment and controls, earthing, enclosure of equipment. The effect of the schematic arrangement of a system on occupational safety is indicated and the hazards present in very high-voltage and low-voltage equipment are discussed. A summary of the main safety rules is given.
Bulletin des Schweizerischen elektrotechnischen Vereins - Bulletin de l'Association suisse des électriciens, 17 Feb. 1973, Vol.64, No.4, p.245-251. Illus.
Experimental findings concerning earthed insulating rods
Rilevazioni sperimentali effettuate su aste isolanti munite di collegamento elettrico a terra [en italiano]
A survey of insulating rods used to operate isolating switches on electric lines or in transformer stations. When certain conditions prevail, a film of condensation water may form on these rods; atmospheric pollution may also result in the formation of a film of soot or various types of dust; near the sea coast, a film of salt may be deposited. These various deposits act as conductors to a greater or lesser degree and may be hazardous for persons manipulating the rods. The article recommends earthing the rods, the author having ascertained by rigorous tests the efficacy of this procedure in the laboratories of the Italian National Accident Prevention Institute (ENPI). Detailed results of his findings are given.
Securitas, 1973, No.5-6, p.561-571.
Measures adopted to safeguard the staff of a 330kV substation
Obespečenie bezopasnosti raboty personala na podstancii 330 kV [en ruso]
Describes the measures adopted to protect maintenance staff from the effects of an electric field (5 to 15kV/m): arrangement of high-tension conductors to minimise the effects of the field; use of screens and protective clothing. 2 types of screen are recommended for biological protection: a revolving screen for the lift cabin and a working screen.
Ėnergetik, Aug. 1973, No.8, p.15-17. Illus.
Electric field surrounding 500kV overhead transmission lines and substations
Naprjažennost' ėlektričeskogo polja na linijah ėlektroperedači i podstancijah 500 kV [en ruso]
Measurements were carried out in the proximity of overhead transmission lines and substations to determine the potential gradient of the electric field and its influence on the maintenance staff. The results enable the following conclusions to be drawn: (a) the potential gradient of the electric field is less than the permissible value (5kV/m at more than 8m below the lowest conductor); (b) this gradient is highest half-way between the 2 pylons and diminishes towards the pylons; (c) it is higher around the outer phase lines than around the central phase line. Work on overhead transmission lines should be organised so as to keep the exposure of personnel within acceptable limits.
Ėnergetik, Aug. 1973, No.8, p.14-15. Illus.
Gladilin L.V., Ščuckij V.I., Inojatov M.B.
Calculation of earthing plates for electrical systems in mines and quarries
K rasčetu zaščitnyh zazemlenij šahtnyh i kar'ernyh ėlektroustanovok [en ruso]
In view of the difficulty of efficiently earthing mine and quarry electrical systems owing to the high resistivity of most of the minerals mined, equations were derived for determining separately the conductivity of phase earth connections and earth circuits. The continuity of the earthing system plays a decisive part.
Gornyj žurnal, Dec. 1973, No.12, p.63-66. Illus. 4 ref.
Live work on high-tension lines
Arbeiten unter Hochspannung [en alemán]
This article discusses the advantages of working on high-tension networks without interrupting the current flow, thus avoiding cutoff of a sector, and the limitations imposed on this type of work by bad weather. It enumerates the types of operation occurring most frequently (replacing wooden poles, crossbars, insulators, lines) and describes the various types of insulating rods available and the kinds of work that can be performed with them. At the present time there are 22 different tools adaptable to the ends of insulating rods. The article also deals with work from insulating aerial baskets and work with bare hands. Hazards of work under high tension and operating practices followed in France.
Technische Rundschau, 30 Oct. 1973, Vol.65, No.47, p.45-49, and 6 Nov. 1973, No.48, p.41-45. Illus. 3 ref.
A model for the earthing and short-circuiting of a 2nd category line
Une maquette sur la mise à la terre et en court-circuit d'une ligne de 2e catégorie. [en francés]
Presentation of a model for illustrating and facilitating the study of the situations which may be encountered in the course of work on a disconnected 3-phase overhead network. The model represents a 20kV line fed by a 10 MVA station stepping down the voltage from 63 to 20kV. Measuring devices can be attached to figures representing linemen, to indicate the voltage and current passing through them. The consequences of earthing 1, 2 or 3 phases of the line can be studied, as well as the problems of insulating the controls of overhead switches and the step voltage near an earthing device emitting a fault current.
Vigilance, Sep. 1973, No.47, p.27-36. Illus.
Protective measures against indirect contacts with metal sheathing
Schutzmassnahmen gegen indirektes Berühren an Metall-Schutzschläuchen [en alemán]
To ensure the proper working of electric installations and equipment (especially machine tools), protective metal sheathing is being increasingly used. According to regulations VDE 0113 of the Association of German Electrical Engineers, cables with metallic sheathing cannot be approved unless they incorporate a system which protects the sheath from becoming live accidentally (excessive contact voltage). The article examines to what extent earthing to neutral and fault-current relays can preclude the hazard of dangerous contact voltage forming and afford adequate protection against fires. Protection by fault-current relay is considered to be particularly efficient.
Industrie-Elektrik und Elektronik, Sep. 1973, Vol.18, No.18, p.426-429. Illus. 5 ref.
The physiological effects of work in the vicinity of 400 kV and 500 kV outdoor installations.
English translation of an article in Russian, published in Naučnye raboty institutov ohrany truda VCSPS, Moskva, USSR, 1967, No.46, p.34-39. Describes a study undertaken to determine the physiological effects of a 50Hz high-voltage electric field on staff working on 400-500kV outdoor installations after complaints of impaired health, fatigue, drowsiness and headaches. Physiological changes observed include: vagotonic changes in the cardiovascular system; weakening of temperature control processes; reduction in resistance to electric current; functional mobility of neuro-muscular apparatus of the hand; and weakening of neurodynamic processes in the brain cortex. These functional changes were marked in maintenance workers and absent or weakly exhibited by operational staff, the degree of change being directly related to duration of exposure to electric field. Indices of vegetative functions and speech-motor reactions are given in tabular form.
O.A. Translation 853, The Electricity Council, Overseas Activities Translation Service, 30 Millbank, London Sw1P 4RD, United Kingdom, 1973. Illus. 3 ref. Price: £3.00.
Fire prevention and protection - Carbon dioxide in fire extinguisher systems.
One of the hazards associated with the use of CO2 in fire extinguishers is the production of very high electrical charges during release, which may ignite explosive mixtures if such are present. Measurements showed that small solid particles of CO2 are produced containing static electricity with voltages of 10-20 kV and potential spark energies easily capable of igniting the lower paraffins. Nitrogen is preferred to CO2 in fire-fighting systems since it does not produce solid particles when releasing the pressure and the amount of static electricity is less pronounced, but the use of solid CO2 generators is suggested as a safe way to replace air by a non-explosive mixture in a reaction vessel.
Quarterly Safety Summary of the British Chemical Industry Safety Council, Apr.-June 1973, Vol.44, No.174, p.10. 1 ref.
Šafran L.M., Davydova E.A., Plisov G.A., Golubkov P.E.
Industrial hygiene evaluation of the static electricity accumulation potential of plastics used on board ships
Gigieničeskaja ocenka polimernyh materialov na sudah, kak istočnikov statičeskogo ėlektričestva [en ruso]
The electrostatic field on the surface of plastics used for the interior fittings of ships depends on microclimatic conditions (relative atmospheric humidity), the duration of previous use of the ship, the degree of saturation of premises with plastics and their arrangement. Measurements carried out showed that this charge is often 2 to 3 times greater than the 200V/cm established by existing provisional standards. It is possible to reduce the electrostatic charge by using wood and metals together with plastic. The mounting of plastic strips by means of metal laths has proved most efficacious.
Gigiena i sanitarija, Dec. 1973, No.12, p.31-34. 7 ref.
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