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Federation of Industrial Mutual Accident Insurance Associations (Hauptverband der gewerblichen Berufsgenossenschaften).
Guidelines for electrostatic coating with liquid paints
Richtlinien für elektrostatisches Versprühen von flüssigen Anstrichstoffen (elektrostatisches Lackieren) [en alemán]
These guidelines apply to manual equipment and fixed installations for electrostatic paint spraying. Definitions, general conditions, pertinent electrotechnical standards and regulations, explosion and fire protection, marking, technical data, checking before starting work, access to spray booths, electrical installations, conductivity of flooring, earthing, personal protective equipment.
Carl Heymanns Verlag KG, Gereonstrasse 18-32, 5000 Köln 1, Federal Republic of Germany, 1979. 11p.
Federation of Industrial Mutual Accident Insurance Associations (Hauptverband der gewerblichen Berufsgenossenschaften), 1 Apr. 1979.
Electrical installations and equipment
Elektrische Anlagen und Betriebsmittel [en alemán]
These safety regulations also apply to non-electrical work in the vicinity of electrical installations. They lay down principles for qualification of personnel, operation of installations and use of equipment, maintenance, and protection against direct and indirect contact. Also dealt with are: testing, work on or near conductive elements. Appendix: rules for implementation, commentary, list of regulations and standards in force.
Carl Heymanns Verlag KG, Gereonstrasse 18-32, 5000 Köln 1, Federal Republic of Germany. 7 + 27p. Price: DM.2.40.
Electrical effects in dust filters.
Electrically active materials (resin wool, electret, synthetic fibres) used as respirator filters are described and compared. X-ray discharge and other methods of measuring the charge on the materials are discussed together with the influence of the charge configuration on particle capture efficiency. The mechanisms by which captured aerosols may reduce the effectiveness of the charge are discussed, with experimental results for a NaCl aerosol.
In: The Second World Filtration Congress 1979, Uplands Press, 1 Catharine Street, Croydon, United Kingdom, 1979, p.291-301. 9 ref.
Electrical diagrams for industrial machinery and safety
Schémas électriques des machines industrielles et sécurité. [en francés]
This booklet is intended for industrial equipment design offices, teachers and students in industrial electrical engineering, and plant electricians. Contents: role of the electrician involved in equipment design; French regulations, official directives and standards; elaboration of the diagram on the basis of the essential functions of the machine (shutdown, protection of circuits and persons, stop control, manual or automatic operation, inspection); technical data (signal lamps, electric protection, switches, cables, switchboard cabinets, connections).
Edition INRS No.581 (Code commande No.11385), Institut national de recherche et de sécurité, 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, Dec. 1979. 47p. + plates. Illus.
Karakaj V.D., Kliško B.K., Gorbačev N.I., Zubko M.P.
Voltage limiter for no-load operation of a welding transformer
Ograničitel' naprjaženija holostogo hoda svaročnogo transformatora [en ruso]
A no-load voltage limiting device that can be adapted to any welding transformer is described with circuit diagram. The device automatically limits the welding-circuit voltage to 12V less than 0.5s after interruption of the welding current and 0.02s after striking the arc (3-5A).
Bezopasnost' truda v promyšlennosti, Sep. 1979, No.9, p.38-39. Illus.
Muss K.B., Šuleckaja S.P.
Fault current protective device
Ustrojstvo zaščity ot uteček toka UZUT [en ruso]
A circuit breaker based on monitoring of the operating d.c. voltage is described with schematic diagram. The switching element is fitted together with an insulation resistance measuring device. Sensitivity and response time were improved by comparison with conventional protective devices. Breaking of the damaged circuit occurs by means of a thyristorised relay.
Bezopasnost' truda v promyšlennosti, Sep. 1979, No.9, p.31, 35-36. Illus.
Buhgol'c V.P., Potapov V.D., Torgovkin Ju.I.
Improved safety of operation of materials handling machinery in mines
Povyšenie bezopasnosti raboty gornotransportnyh mašin [en ruso]
A capacitive device for detection of live power lines designed to be fitted on power shovels, draglines and other equipment moving along trains of mine cars is described. It detects the presence of an electric field at a distance of 14m and can stop the movement of the machine at a distance of 0.2-0.4m, stoppage occurring at a distance of 0.1-0.2m between the line and the bucket or jib. Vibration does not interfere with operation.
Bezopasnost' truda v promyšlennosti, Sep. 1979, No.9, p.28-30. Illus.
Ščuckij V.I., Sidorov A.I., Sitčihim Ju.V.
Permissible contact duration for electric currents
O dlitel'no dopustimyh tokah i naprjaženijah prikosnovenija [en ruso]
Studies in 10 men to determine the electrical resistance of the human body in relation to the duration of passage of an alternating current of 12V 50Hz and a direct current of 50V 25mA are reported. Arm-to-arm current circuit was used. Duration was 5min. Formulae are given for body resistance to a.c. and d.c. permitting calculation of the probable intensity of the breakthrough current. For prolonged contact a permissible voltage of 24V for a.c. and of 50V for d.c. (with a threshold current of 25mA) is proposed.
Gornyj žurnal - Izvestija vysših učebnyh zavedenij, June 1979, No.6, p.99-101.
Work near overhead powerlines or underground cables
Travaux ŕ proximité des lignes électriques aériennes et des câbles souterrains. [en francés]
These technical rules draw attention to lesser known aspects of protection such as the inadequate protection provided by rubber shoes or tyres. Many examples are given. Contents: general remarks; possibilities of contact (direct, via tools, construction equipment or materials, tall equipment); safety measures near overhead lines (organisation, safe distances, disconnection, placing of barriers, delimitation of work area, insulating coverings, marking and warning signs); safety measures near underground cables; measures in the event of an accident.
Edition OPPBTP No.201 A 79, Organisme professionnel de prévention du bâtiment et des travaux publics, 2bis rue Michelet, 92130 Issy-les-Moulineaux, France, 1st edition, Oct. 1979. 31p. Illus.
Fire fighting in and near electrical installations
Bekämpfung von Bränden in elektrischen Anlagen und in ihrer Nähe [en alemán]
Commentary on data sheet VDE 0132/2.79 of the Association of German Electrical Engineers, (effective in 1979), which gave rules on the minimum distance to be kept between the orifice of the fire lance and live electrical installations. The minimum distances were reduced depending on voltage and lance orifice design. When in contact with the live element, the water should be sprayed so as not to create an electric connection. A table is provided as an aid to remembering the statutory distances for a full jet or spray in the presence of low or high voltage when the precise voltage is unknown.
D E - Der Elektromeister und Deutsches Elektrohandwerk, 1979, No.18, p.1377-1378.
High voltage industrial control equipment.
This standard, approved as an American national standard on 16 Oct. 1978, applies to enclosed industrial control equipment and associated components intended for starting, stopping, regulating, controlling, or protecting electric motors or other electrical loads including refrigeration equipment, having a.c. voltage ratings in the range of 2.2-2.5kV or 4.0-5.0kV, including fire pump controllers, but not equipment for use in hazardous locations. Contents include: definitions; construction (guarding and accessibility of live parts; earthing and bonding; protective devices; overload relays; isolating; interlocking); performance; rating; marking.
ANSI/UL 347-1978, Underwriters' Laboratories, 207 East Ohio Street, Chicago, Illinois 60611, USA, 15 Jan. 1979. 44p. Illus. Price: US$5.00.
Nature and occurrence of static electricity; spark and shock hazards; prevention of accumulation of static charges; bonding and earthing;; accumulation in shoes and clothing; ionisation of air by high-voltage a.c. static neutralisers producing an electric corona, by gas flames and by radioactive static eliminators; static collectors; humidity control; static accumulation during transfer of flammable liquids; generation of static electricity (by high-velocity steam when cleaning tanks and containers, by moving belts); hazards of dust explosions and premature explosions due to static electricity induced on blasting cap wiring.
Data Sheet 1-547-79, Revised 1979, National Safety Council, 444 North Michigan Avenue, Chicago, Illinois 60611, USA, 1979. 6p. Illus. 5 ref.
Elektromonter [en polonés]
Pocket-size manual for electricians containing detailed instructions for safe work with electrical installations, networks and substations. Rational organisation of work performed, general service rules and rules for maintenance, checking and repairs. Rules for checking equipment on delivery; required qualifications for electricians. Current protection; fire precautions; first aid in case of electrocution, injury. burns, poisoning. List of Polish regulations. The handbook can be used by labour inspectors and safety officers.
Instytut wydawniczy CRZZ, Warszawa, Poland, 1979. 176p. Illus. 4 ref. Price: Zl.20.00.
Medium-voltage switching stations
Mittelspannungsschaltanlagen [en alemán]
These stations connect and disconnect electric lines supplying voltages of 1-52kV. Their basic circuits (utilising single or double bus bars) are described and their construction is discussed from the point of view of conductor insulation, and cell design (open, metal-clad, solid insulation) and manufacture (prefabrication, on-site assembly). The effects of fault arcs, protective measures against them, and advantages and disadvantages of unipolar or bipolar controls for isolating switches are examined.
Elektrotechnik und Maschinenbau, Aug. 1979, Vol.96, No.8, p.351-357. Illus.
Nikolić N.Lj., Petrović M.V.
Hazards of electric current and electrical safety
Opasnost i zaštita od električne struje [en serbocroata]
Contents: physical principles; voltage, current, and resistance measuring instruments; electricity production (accumulators, transformers, alternators) and electric motors; special electric machinery (regulating, welding, electric furnace transformers; fire safe and other transformers); electric power stations and substations; aerial and underground power lines; electrical accident hazards and safety measures (protection against contact voltage and direct contact in low and high voltage installations, insulation, earthing and connection to neutral, inspection of earth and neutral electrodes; explosion safety, static electricity and its elimination (with Yugoslav regulations), lightning protection, first aid).
Institut za dokumentaciju zaštite na radu, ul. Višegradska bb, Niš, Yugoslavia, 2nd edition, 1979. 622p. Illus. 79 ref.
Karmazinov N.M., Lobyzov N.I., Novokovskij V.I.
Safety of static electricity measuring instruments
Bezopasnost' izmeritel'nyh ustrojstv statičeskogo ėlektričestva [en ruso]
Considerations on the use of luminescent discharge lamps in explosive atmospheres. Establishment, by mathematical analysis of the values involved, of the conditions applying to the use of these lamps as potential limiters (to limit to 0.2V/s the speed of increase of feed voltage). On-site tests in mines have demonstrated the reliability of measuring instruments incorporating these lamps.
Bezopasnost' truda v promyšlennosti, July 1979, No.7, p.52-54. Illus.
Chakrabarti M.K., Gupta R.K.
Fire hazards potential of static charge and other fire hazards in cotton ginning process - An investigative study.
The roller ginning process is described, and the static electricity hazard investigated: generation and accumulation of static charges during roller ginning were not sufficient to cause sparks and thus do not represent a fire hazard. Most fires occurring in cotton ginning factories were due to the absence of systematic inspection to identify and eliminate well-known fire hazards, and to lack of supervision, training and education. Recommendations aimed at preventing these hazards are made.
Safety Wing, Central Labour Institute, Sion, Bombay-400 022, India, 1979, 12p.
Antoni H., Biegelmeier G.
The effects of direct current on humans
Über die Wirkungen von Gleichstrom auf den Menschen [en alemán]
The present state of knowledge is reviewed and the resistance of the human body during passage of direct current is outlined. Studies on the fibrillation threshold in direct current and physiological considerations on the fibrillation mechanism are discussed. The current strength ranges proposed and contact voltage limits for direct current are important for electrotechnical standard setting.
Elektrotechnik und Maschinenbau, Feb. 1979, Vol.96, No.2, p.71-81. Illus. 25 ref.
Serrano Soriano J.
Protección ocular contra arcos eléctricos accidentales
Brief description of the different light wavelength in an electric arc (2,000-200nm); maximum permissible values in Spain according to wavelength of UV radiation, which is the most hazardous (e.g. 100mJ/cm2 for 200nm; 1,000mJ/cm2 for 315nm). The efficacy of filter safety glasses and the type of eye protection required for various welding processes are shown in synoptic tables. Brief review of 41 case studies of electric arc photophthalmia.
Medicina y seguridad del trabajo, Apr.-June 1979, Vol.27, No.106, p.31-36. 7 ref.
Effect of electric fields on the human body
Wirkung elektrischer Felder auf den Organismus [en alemán]
Report on the results of animal experiments to ascertain the possible harmful effects of electric fields (especially near overhead lines and high voltage cables) on the body. Data on the propagation of an alternating electric field, the intensity of the field at the surface of, and inside the human body; description of the methods used for experiments on rats and cats. The influence of electric fields (50Hz, 60-80kV/m) on the body was determined by continuous measurement of the electrical activity of the heart, respiratory rate, arterial blood pressure, electrical activity of the brain, and temperature. The results, which are shown in diagrams and tables, show no apparent change due to the electric field, except for some emotive reactions probably due to the vibration of the animals' fur.
Medizinisch-technischer Bericht 1979, Institut zur Erforschung elektrischer Unfälle, Oberländer Ufer 130, 5000 Köln 51, Germany (Fed.Rep.), 1979. 39p. Illus. 10 ref.
Lüttgens G., Boschung P.
Static electricity - Causes and elimination
Elektrostatische Aufladungen - Ursachen und Beseitigung [en alemán]
This handbook gives a roundup of information on static electricity phenomena to facilitate choice of suitable preventive measures. Introduction: static electricity building-up and how it originates (physical laws and principles, structure and properties of matter, origin of static electricity). Chapters are devoted to: methods for measuring static electricity; nuisance effects and health hazards of static electricity in man, and how it affects some technical systems (especially electronic components); hazards where gases and flammable liquids are present; methods for prevention and elimination of static electricity in the case of solids and liquids (illustrated by practical examples and summarised in a list of basic rules).
Band 44, Reihe Kontakt und Studium, Technische Akademie Esslingen. Expert Verlag GmbH, Maichinger Strasse 16, 7031 Grafenau, Germany (Fed.Rep.), 1979. 195p. Illus. 99 ref. Price: DM.32.80.
The construction machine: power line hazard.
The hazards of working with cranes near overhead electric lines are illustrated. Distance is the best safety measure: 10ft for up to 50,000V and then 1ft for each 30,000V above 50,000V. Accident prevention measures are detailed. The advantages and disadvantages of insulating, proximity sensing and crane motion limiting devices, and earthing are discussed.
Professional Safety, Sep. 1979, Vol.24, No.9, p.15-20. 8 ref.
Static electricity and plastics.
This article examines the causes of fire hazards due to work with plastics, which, as they are generally little affected by the level of humidity, consequently increase the problems and hazards of static electricity. Conditions in which sparks can start a fire are considered: spark energy dissipation, flammable mixture concentration, spark voltage >5,000V, insulation from earth, Lichtenberg discharge.
Industrial Safety, July 1979, Vol.25, No.7, p.11-12. Illus.
Determination of impedance in the passage of current from hand to hand
Ermittlung der Impedanz beim Stromweg Hand-Hand [en alemán]
The physiological effects of electric current in relation to its duration of passage are presented succinctly in a table. For a given voltage, the intensity of the current depends on the impedance of the human body. The conditions in the body are reproduced by models of electrical circuits. Results of measurements taken with 10 human subjects (hands wetted with a saline solution). The values were partly above 1,100Ohm for a voltage of 25V.
Sichere Arbeit, 1979, Vol.32, No.2, p.5-7. Illus. 2 ref.
5th International Colloquy on the prevention of occupational risks due to electricity - End report.
5e Colloque international sur la prévention des risques professionnels dus ŕ l'électricité - Rapport final. [en francés]
The report of this technical meeting (Lucerne, Switzerland, 17-19 May 1978) reproduces the text of the main address and the contributions and comments on the theme: safety for electricians, and their basic and advanced training. Some of the 39 papers published are devoted to training problems and methods in various countries (Austria, France, Germany (Fed.Rep.), Hungary, Spain, Switzerland, USSR); others are concerned with special technical subjects having a direct impact on the prevention of electrical accidents: electrophysiology, hazards of explosive atmospheres, electrical accidents and preventive measures, live work and work near live installations, training programmes and methods, work on building sites. The contributions and comments are reproduced fully in the original language, with a summary (the basic address is, however, translated in full) in the 2 other working languages. An earlier ISSA publication containing summaries of the contributions and papers presented was abstracted as CIS 78-1221.
International Social Security Association, 1211 Genčve 22, Switzerland, 1979. 473p.
Proteau J., Robert L., Cabanes J., Folliot D.
Accidents due to electricity
Accidents dus ŕ l'électricité. [en francés]
This medical encyclopaedia article gives a roundup of knowledge concerning these accidents, considered in 2 separate groups: occupational accidents involving the 3 voltage categories, and home accidents usually involving low voltage current only. Contents: statistical and aetiological data; physio-pathology (severity factors, processes leading to fatal outcome, different thresholds, burns, etc.); clinical study (low-voltage electric shock, burns, cardiovascular and neurological manifestations, kidney damage, sequelae, disability, diagnosis, treatment). A large part of the article is devoted to the prevention of accidents due to natural electrical phenomena and to electricity in industry and in the home, and the safety principles applicable to different types of contact and different parameters connected with electrical hazards. The text is illustrated by numerous diagrams.
Encyclopédie médico-chirurgicale. Maladies causées par les agents physiques, Fascicule 16515 A10, 2-1979, 18 rue Séguier, 75006 Paris, France, 16p. Illus. 74 ref.
This article taken from the author's "Industrial Hazard and Safety Handbook" (published by Newnes-Butterworth) considers the hazards of static electricity, how it is formed during some processes (removal of dust from gases, some paint spraying and printing processes) and the phenomena it causes (mainly ignition hazards, but also unexpected shocks in humans, false readings of sensitive instruments, deposit of dust in unwanted places). The author considers the natural build up of static electricity (flow of products in pipes, splash filling, friction from belts, tyres, agitators) and describes some typical accidents (explosions in hospital operating theatres, in oil tankers). A mathematical formula for the electrical quantities involved is given, with a description of methods of protection against static (earthing and bonding, increasing conductance of floors, footwear, wheels, etc., increasing conductivity of non-conductors, ionisation), methods for measurement of electrostatic charge, special ignition hazards and precautions (gas discharges, flammable liquids, combustible powder handling), electrostatic paint spraying, and electrostatic dust removal in printing.
Industrial Safety, Feb. 1979, Vol.25, No.2, p.14-17. Illus. 21 ref.
German Electrotechnical Commission (Deutsche Elektrotechnische Kommission).
Equipment for operation and testing of live electrical equipment with rated voltage more than 1kV
Geräte zum Betätigen und Prüfen unter Spannung stehender Betriebsmittel mit Nennspannungen über 1kV [en alemán]
This DIN/VDE standard covers insulating rods (parts 1 and 2); rods equipped with a tong for fuse replacement (part 3); zero voltage tester for alternating current (Part 4). Definitions, characteristics, use, testing.
DIN 57 681, Teil 1-4; VDE 0681, Teil 1-4; Beuth Verlag GmbH, Burggrafenstrasse 4-10, D-1000 Berlin 30, Aug. 1978. 59p. Illus.
German Electrotechnical Commission (Deutsche Elektrotechnische Kommission).
VDE regulation on personal protective equipment, protective devices and tools for live work on electrical plant up to 1000V
VDE-Bestimmung für Körperschutzmittel, Schutzvorrichtungen und Geräte zum Arbeiten an unter Spannung stehenden Betriebsmitteln bis 1000V [en alemán]
This DIN/VDE standard applies to insulated hand tools (screwdrivers, pliers, shears, cable cutters) for nominal voltages of 1000V AC or 1500V DC. It gives definitions, required characteristics and testing conditions.
DIN 57 680, Teil 2; VDE 0860, Teil 2, Beuth Verlag GmbH, Burggrafenstrasse 4-10, D-1000 Berlin 30, Mar. 1978. 22p. Illus.
Electrical accidents during work on low-voltage distribution installations
Stromunfälle beim Arbeiten an Niederspannungsverteilungen [en alemán]
Electrical accidents between 1969 and 1975 are analysed on the basis of insurance records. Work on distribution equipment is now the commonest cause of electrical accidents (total 2,660, including 28 fatal accidents over the period of the report). Three possible causes of this rising trend are analysed: inadequate training and qualification, increased frequency of such work, installation design modifications. Statistical data are given. Reduction in external dimensions of equipment and of distances between live elements make work more difficult and are a cause of accidents. Conclusions regarding prevention: improved design, use of insulating blankets or covers, application of ergonomic rules and periodical information on safety measures. Annex: description of typical accidents, additional statistics.
Technischer Bericht 1978, Institut zur Erforschung elektrischer Unfälle, Oberländer Ufer 130, 5000 Köln 51, Germany (Fed.Rep.), 1978. 65p. Illus.
Lövsund P., Hansson Mild K.
Low-frequency electromagnetic fields around heating inductors
Lĺgfrekventa elektromagnetiska fält kring nĺgra induktionsvärmare [en sueco]
Results are reported of measurements on induction-heated tools used for brazing, forging and quenching, to determine the intensity of the electric and magnetic fields (frequencies 3,830 and 10,320Hz) around the inductors. A literature survey gives details of the biological effects of low-frequency electromagnetic fields (fatigue, headache, reduced arterial blood pressure and white blood cell counts, magnetophosphenes, etc.). While a limit of exposure to these electromagnetic fields cannot be established, measures must be taken to reduce exposure to a minimum, especially in the case of high-frequency induction current.
Undersökningsrapport 1978:38, Arbetarskyddsstyrelsen, Fack, 100 26 Stockholm, Sweden, 1978. 21p. Illus. 33 ref.
Ignition hazard of work clothes in the electric arc
Brandgefahr von Arbeitskleidung im elektrischen Lichtbogen [en alemán]
Tests on the behaviour of textiles exposed to fire (see also CIS 78-195) with samples of pure cotton or polyester-cotton (65%/35%) are reported. Combustion and extinction characteristics of these fabrics are different. A 65% polyester content slows down combustion of the fabric and improves the extinction characteristics, but has the disadvantage of melting, with resulting aggravation of burns. A blended fabric is as suitable as pure cotton for work clothes for routine use. In the event of high risk, the use of personal protective equipment is recommended.
Die Berufsgenossenschaft, Sep. 1978, No.9, p.503-506. Illus. 9 ref.
Hansson Mild K., Lundström R., Nordström B.
Instruments for the near-field measurement of radiofrequency electric and magnetic fields
Instrument för närfältsmätningar av radiofrekventa elektriska och magnetiska fält [en sueco]
To evaluate exposure to radiofrequency radiation and to observe the limits of exposure prescribed in Directive No.111 of the Swedish National Board of Occupational Safety and Health (CIS 77-1313) the intensity of the electric and magnetic fields must be measured. This report describes 2 instruments designed and tested for this purpose, one (for measuring electric field intensity) designed for a frequency range of 10-100MHz and for equivalent energy densities of 0-1,000W/m2, and the other (for measuring magnetic field intensity) for a frequency range of 10-60MHz and maximum intensities of 3A/m at 27MHz.
Undersökningsrapport 1978:26, Arbetarskyddsstyrelsen, Fack, 100 26 Stockholm, Sweden, 1978. 18p. Illus. 11 ref. Price: Swe-cr.10.00.
Musijačenko V.A., Kiričenko V.I., Fefer A.I.
Automatic high-voltage circuit breaker
Pribor-avtomat dlja otključenija vysokogo naprjaženija [en ruso]
A high-voltage detector worn around the wrist is described. When the hand approaches a conductor carrying a high-voltage current the alternating electromagnetic field of the conductor excites a capacitive detector. The signal is amplified and transmitted to a receiver on the switch board where it trips a circuit-breaking relay. The range of action is 15-20m. Electrical diagrams are shown.
Bezopasnost' truda v promyšlennosti, Oct. 1978, No.10, p.30-31. Illus.
Bartussek W., Küttner J.
Measurement of body resistance in living subjects
Messung des Körperwiderstandes an lebenden Personen [en alemán]
The experimental conditions are described with results. Resistance was measured in 3 situations: direct-current voltage, and 50Hz and 2kHz alternating-current voltage (peak level 35V). Evaluation was done with consideration of the resistance limiting the making current. Diagrams show the values for impedance and current limiting resistance measured. The constancy of the current limiting resistance is stressed.
Elektrotechnik und Maschinenbau, Jan. 1978, Vol.95, No.1, p.1-2. Illus. 1 ref.
Results of studies on electrostatic charges during filling of large silos with flammable dusts
Versuchsergebnisse über elektrostatische Aufladungen beim Füllen grosser Silos durch brennbare Stäube [en alemán]
Ignition by static electricity during filling of silos may occur by way of 2 mechanisms: electrostatic discharge from conductive components, or a lightning-like discharge from the dust cloud. The article deals with the 2nd mechanism, prevention of which is a difficult matter: value of the charges and their distribution in the silo, electrostatic effect of the level-indicator or thermometer suspension ropes. Measurements during and after filling large silos with soya meal showed that electrostatic charges in the dust cloud do not reach levels necessary for a flash discharge. Petrol vapours may be released in silos filled with soya after oil extraction. Conclusions relate to partition of silos, desorption of soya after extraction, and use of suspended probes.
Heft 22, Moderne Unfallverhütung, Vulkan-Verlag Dr. W. Classen, Haus der Technik, 4300 Essen, Germany (Fed.Rep.), 1978. p.101-106. Illus. 3 ref.
Dörr G., Preisendanz H.
Electrostatic charges in oxygen piping due to dust particles in the oxygen stream
Elektrostatische Aufladungen in Sauerstoffleitungen, verursacht durch Staubanteile in der Sauerstoffströmung [en alemán]
The possibility of accumulation of electrostatic charges and the ignition hazards resulting from solid impurities (rust or scale, metal chips, etc.) in the oxygen network are studied. The experimental model corresponded to conditions found in oxygen-converter steelworks. Measurements related to the effect of length and constituent material of the piping on the electrostatic charge, and of particle size, pressure, or velocity and concentration of impurities on the charge. Conditions for an electrostatic discharge and hazards of oxygen ignition in the piping are considered. Conclusion: while electrostatic charges can accumulate, conditions necessary for ignition caused by a discharge are not met.
Heft 22, Moderne Unfallverhütung, Vulkan-Verlag Dr. W. Classen, Haus der Technik, 4300 Essen, Germany (Fed.Rep.), 1978, p.95-101. Illus. 17 ref.
Safety hints for work on low-voltage electrical equipment and installations
Conseils de sécurité pour interventions et travaux sur les équipements et installations électriques de la classe basse tension. [en francés]
This profusely illustrated brochure is addressed to those responsible for work on this equipment. Contents: general remarks (definitions, classification of equipment, measuring apparatus, tools, etc.); work on equipment supplied by low-voltage installations (procedure, live work, repair, restarting equipment); work on low-voltage installations (shutdown procedure, disassembly, construction of a new installation, modification or maintenance, work on dead equipment); fire in low-voltage equipment and installations (general procedure, use of portable extinguishers, additional precautions).
Edition INRS n°539, Institut national de recherche et de sécurité, 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, Apr. 1978. 77p. Illus.
Dazzle at welding.
The causes of effects of glare (effects of luminance distribution in the workers' visual field on glare, relation between glare and workplace lighting) are discussed. The degree of glare is estimated by mathematical formulae. Welding with a thin electrode may be more difficult than with a thick one because of an uneven distribution of luminance. Glass screen permeability can be calculated in order to select the proper glass for given luminance conditions.
Bulletin of the Institute of Maritime and Tropical Medicine in Gdynia, 1978, Vol.29, No.3-4, p.199-209. Illus. 8 ref.
Electricity - How to use it safely
L'électricité - Comment s'en protéger. [en francés]
This booklet of a somewhat elementary nature, illustrated by humours drawings, is intended for the non-electrician. Contents: origin and properties of electricity; electrical hazards; prevention of electrical hazards (practical rules).
Edition INRS No.548, French National Research and Safety Institute (Institut national de recheche et de sécurité), 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, 1st edition, July 1978. 56p. Illus.
Construction, use and testing of partially and fully insulated ladders
Ausführung, Anwendung und Prüfung von teil- und vollisolierten Leitern zur Standortisolierung [en alemán]
The use of metal or plastic ladders is growing in chemical manufacturing plants and electrical installations. Glass-fibre-reinforced thermosetting plastic ladders have satisfactory mechanical properties. Plastic uprights and rungs ensure full insulation; plastic uprights with light alloy rungs, partial insulation. Various types of ladders are described, with the results of electrical tests (dielectric strength, leakage current, breakdown voltage). Practical aspects dealt with are: short-circuit hazard with partially insulated ladders, earth contact hazard of metal ladders, fully insulated ladders for live work, properties of glued plastic ladders and their use in live work.
Sicherheitsingenieur, June 1978, Vol.9, No.6, p.26-41. Illus.
Safety of direct current electric drives used underground
Issledovanie bezopasnosti podzemnyh ėlektroprivodov postojannogo toka [en ruso]
Results are reported of a study on the magnitude of currents passing through the body on contact with a phase or pole of a network comprising a rectifier. Not only the connection circuit of the rectifier, but also the location of the rectifier in the supply circuit is of prime importance for electrical safety and the safe use of networks insulated from earth installed underground. Optimum safety conditions are assured when the rectifier is installed in the immediate proximity of the substation or when the rectifier and supply transformer are housed in the same enclosure. It is recommended that the length of the alternating current cable to the rectifier be kept to a minimum.
Bezopasnost' truda v promyšlennosti, June 1978, No.6, p.33-37. Illus.
Electrostatic charging during pneumatic conveying of granulates in conductive pipework
Beitrag zur elektrostatischen Aufladung beim pneumatischen Rohrleitungstransport körniger Güter im leitenden Rohr [en alemán]
A working hypothesis was used to establish the functional relations between the specific charge of the material handled and various characteristics of a pneumatic conveying installation. The relations are expressed mathematically and compared with data from the specialised literature. The results permit characterisation of the electrostatic charging process in the conductive conveyor pipe.
Elektrie, 1978, Vol.32, No.3, p.160-161. 14 ref.
Gamberale F., Knave B., Bergström S., Birke E., Iregren A., Kolmodin-Hedman B., Wennberg A.
Exposure to electrical fields - An epidemiological health survey of long-term exposed substation workers.
Exposition för elektriska fält - En epidemiologisk hälsoundersökning av lĺngvarigt exponerade ställverksarbetare [en sueco]
The effects of electric fields in 400kv substations were examined in 53 workers exposed more than 5 years and compared with a non-exposed matched control group. The investigation included the nervous system (neurasthenic symptoms, psychological tests, EEG), cardiovascular system (symptoms, blood pressure, ECG), the blood (haemoglobin, red blood cells, reticulocytes, white blood cells including differential count, thrombocytes, sedimentation rate) and fertility. There were no differences between the exposed and control groups due to the electric fields. However, the exposed group had consistently better results in the psychological tests, but these differences were ascribed to higher education. Evaluation as to "acute" effects of exposure at some time during the 14 days preceding the examination showed lower psychological test results among the "acute" exposed. No other results indicated the presence of an "acute" effect.
Arbete och hälsa - Vetenskaplig skriftserie 1978:10, Arbetarskyddsstyrelsen, Fack, S-100 26 Stockholm, Sweden. 48p. 35 ref.
Electrostatic powder coating
Elektrostatisk pulversprutning [en sueco]
These directives (entry into force: 1 July 1979) contain safety rules for powder coating booths (design for easy cleaning, exhaust ventilation rate calculated so that the lower explosive limit of the powder/air mixture cannot be reached, flameproof construction of exhaust fan, etc.), workplace premises (conductive flooring to facilitate cleaning and eliminate static electricity, adequate ventilation, etc.), electrical equipment (construction for personnel safety and explosion prevention), earthing (handle of spray gun, workshoes with conductive soles, etc.), protection against fires and maintenance of electrostatic coating equipment (skilled personnel, handling of powders without raising dust cloud, etc.). Reproduction of 2 warning notices for workplace display.
Anvisningar nr 12:2, National Board for Occupational Safety and Health (Arbetarskyddsstyrelsen), Fack, 100 26 Stockholm, Sweden, Apr. 1978. 11p.
5th International Colloquy on the prevention of occupational risks due to electricity - Safety for the electrical expert - His basic and advanced training.
5e colloque international pour la prévention des risques professionnels dus ŕ l'électricité - Sécurité pour le spécialiste électricien - Sa formation et son perfectionnement. [en francés]
Volume containing abstracts (in English, French and German) of 34 reports submitted to the colloquy, which was held in Lucerne, Switzerland (17-19 May 1978) under the auspices of the International Social Security Association (ISSA), Geneva, Switzerland, and its International Section for the Prevention of Occupational Risks due to Electricity (Cologne, Germany) and the Swiss National Accident Insurance Fund (Schweizerische Unfallversicherungsanstalt), Lucerne, Switzerland. The abstracts are grouped under 6 main headings: basic training programme for the electrical expert in matters of accident prevention; procedure and methods used for theoretical and practical training; technical and didactic educational aids; instruction given to the electrical expert to qualify him for work in specially dangerous areas; advanced training and refresher course for the electrical expert; possibilities of influencing awareness and safety-mindedness by publicity campaigns. The full texts of the reports and communications will be published in a second volume.
ISSA International Section on the Prevention of Occupational Risks due to Electricity, Berufsgenossenschaft der Feinmechanik und Elektrotechnik, 130 Oberländer Ufer, 5000 Köln 51, Germany (Fed.Rep.), 1978, Vol.1. 251p. Illus.
Live work, as seen by the Inspectorate of Heavy Current Installations
Les travaux sous tension vus par l'Inspection des installations ŕ courant fort. [en francés]
This article reviews breifly the Swiss regulations concerning live work, and gives the viewpoint of the Swiss Inspectorate of Heavy Current Installations with regard to live work on low voltage distribution networks (<1,000V). Giving examples, the author reviews various safety measures capable of preventing occupational accidents during live work on low voltage installations. Experience shows that, provided these measures are observed, skilled and experienced workers can perform live work without running any particular risk. In the case of low voltage installations the Inspectorate endorses the saying: "it is better to work on a live installation, being aware of the fact, than to work on an installation presuming that it is disconnected".
Bulletin des Schweizerischen elektrotechnischen Vereins - Bulletin de l'Association suisse des électriciens, 11 Feb. 1978, Vol.69, No.3, p.106-109.
Recommended practice on static electricity.
This code of practice updates previous editions and was adopted as American National Standard ANSI/NFPA 77 on 30 Mar. 1978. Definitions are followed by chapters devoted to: generation and accumulation of static energy; dissipation of static electricity (bonding and grounding, humidification, ionisation); control of ignitable mixtures by inerting, ventilation or relocation; flammable and combustible liquids (free charges on surface of liquid; storage tanks; rubber-tyred vehicles; aircraft, tank cars, tankers and barges; container filling; blending and mixing operations); gases (compressed air; carbon dioxide, hydrogen-air, acetylene-air mixtures; LP-gases); dusts and fibres (parameters affecting charge generation, energy available in static discharge); industrial and commercial processes and equipment (coating, spreading, and impregnating; transmission machinery; dry cleaning; printing and lithography; spray finishing; steam jets); static detectors. Appendix: glossary of terms.
NFPA 77-1977, National Fire Protection Association, 470 Atlantic Avenue, Boston, Massachusetts 02210, USA, 1977. 62p. Illus. Price: US-$4.00.
DIN 57 680, Teil 3 und 6, VDE 0680, Teil 3 und 6, German Electrotechnical Commission (Deutsche Elektrotechnische Kommission), Berlin (West), Apr. and Sep. 1977.
VDE Regulations for personal protective equipment, protective devices and tools required for live work on installations carrying current up to 1000V
VDE-Bestimmung für Körperschutzmittel, Schutzvorrichtungen und Geräte zum Arbeiten an unter Spannung stehenden Betriebsmitteln bis 1000V [en alemán]
This document is both a DIN Standard and Regulations of the Association of German Electrical Engineers (Verband Deutscher Elektrotechniker - VDE) and as such forms part of the VDE Code. Part 3 applies to insulating rods for work on electrical installations carrying 1,000 and 1,500V DC rated voltage, and prescribes technical requirements and tests. Part 6 gives technical data on, and test requirements for single-pole voltage measuring equipment.
Beuth Verlag GmbH, Burggrafenstrasse 4-7, D-1000 Berlin 30, 1977. 24p. Illus. Price: DM.20.00.
GOST 11516-73, State Standards Committe (Gosudarstvennyj komitet standartov), Moskva, 12 June 1973.
Tools with insulated handles for work on 1,000V electrical installations - Rules for insulation
Instrument slesarno-montažnyj s izolirujuščimi rukojatkami dlja raboty v ėlektroustanovkah naprjaženiem do 1000V - Trebovanija k izoljacii [en ruso]
This standard (effective 1 Jan. 1974) applies to tools for live work (spanners, pliers, etc.) and lays down technical specifications for compliance: design of insulating handle (attachment, rim preventing fingers from straying beyond the insulated grip, etc.); physical properties of insulating materials (reduced water absorption, dielectric strength, etc.); rules for approval (compliance tests, periodic testing); test methods; marking, packaging, transport and storage; safe working methods; manufacturer's guarantee.
Izdatel'stvo standartov, Novopresnenskij per.3, Moskva D-557, USSR, reprinted 1977. 6p. Price: Rbl.0.03.
Hess H., Liere H.
Safety in electrostatic powder coating
Sicherheit beim EPS-Verfahren [en alemán]
The types of powder used are generally flammable when mixed with air in certain concentrations, and these always occur in the neighbourhood of the spray guns and powder recovery equipment. Ignition can be produced by electrostatic discharges with an energy of at least 5mWs. Conditions leading to spark production between the gun and the workpiece in the booth are examined. Primary safety measures against hazardous accumulation of electrostatic charges on the workpiece are described: control of the insulation resistance of the workpiece (maximum 1 megaohm) before it enters the booth; electrostatic earthing, interlocked with the equipment. Secondary measures: automatic fire detectors interlocked with the booth equipment; automatic extinguishing system; flame arrester in the pipework between the recovery equipment and the spray booth; shut-off valve actuated by the explosion shock wave; explosion vents in the recovery plant; explosion suppression by extinguishers. Recommendations are made for cleaning the booth.
Industrie-Lackier-Betrieb, 1977, No.4, p.133-136. Illus.
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