Related Research Articles
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.
IEC 60320 Appliance couplers for household and similar general purposes is a set of standards from the International Electrotechnical Commission (IEC) specifying non-locking connectors for connecting power supply cords to electrical appliances of voltage not exceeding 250 V (a.c.) and rated current not exceeding 16 A. Different types of connector are specified for different combinations of current, temperature and earthing requirements. Unlike IEC 60309 connectors, they are not coded for voltage; users must ensure that the voltage rating of the equipment is compatible with the mains supply. The standard uses the term coupler to encompass connectors on power cords and power inlets and outlets built into appliances.
A power cord, line cord, or mains cable is an electrical cable that temporarily connects an appliance to the mains electricity supply via a wall socket or extension cord. The terms are generally used for cables using a power plug to connect to a single-phase alternating current power source at the local line voltage. The terms power cable, mains lead, flex or kettle lead are also used. A lamp cord is a light-weight, ungrounded, single-insulated two-wire cord used for small loads such as a table or floor lamp.
A residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) is an electrical safety device that quickly breaks an electrical circuit with leakage current to ground. It is to protect equipment and to reduce the risk of serious harm from an ongoing electric shock. Injury may still occur in some cases, for example if a human receives a brief shock before the electrical circuit is isolated, falls after receiving a shock, or if the person touches both conductors at the same time.
AC power plugs and sockets connect electric equipment to the alternating current (AC) mains electricity power supply in buildings and at other sites. Electrical plugs and sockets differ from one another in voltage and current rating, shape, size, and connector type. Different standard systems of plugs and sockets are used around the world.
Appliance classes specify measures to prevent dangerous contact voltages on unenergized parts, such as the metallic casing, of an electronic device. In the electrical appliance manufacturing industry, the following appliance classes are defined in IEC 61140 and used to differentiate between the protective-earth connection requirements of devices.
Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.
A current transformer (CT) is a type of transformer that is used to reduce or multiply an alternating current (AC). It produces a current in its secondary which is proportional to the current in its primary.
The IP code or ingress protection code indicates how well a device is protected against water and dust. It is defined by the International Electrotechnical Commission (IEC) under the international standard IEC 60529 which classifies and provides a guideline to the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water. It is published in the European Union by the European Committee for Electrotechnical Standardization (CENELEC) as EN 60529.
An earthing system or grounding system (US) connects specific parts of an electric power system with the ground, typically the Earth's conductive surface, for safety and functional purposes. The choice of earthing system can affect the safety and electromagnetic compatibility of the installation. Regulations for earthing systems vary among countries, though most follow the recommendations of the International Electrotechnical Commission (IEC). Regulations may identify special cases for earthing in mines, in patient care areas, or in hazardous areas of industrial plants.
IEC 60906-1 is an international standard designed "to provide a standard for a safe, compact and practical 16 A 250 V AC system of plugs and socket-outlets that could be accepted by many countries as their national standard, even if not in the near future." The standard was originally published by the International Electrotechnical Commission in 1986; the current edition is ed2.0 published in 2009. Although it is almost identical to the Swiss SEV 1011 T12 plug for 10 A 250 V a.c. standardised in 1937, its dimensions are slightly different and its polarization is flipped. As of July 2014, only South Africa has introduced a standard based closely on IEC 60906-1. Brazil used it as the basis for its NBR 14136 standard, but this is not compatible with IEC 60906-1. In 2017 the European Union (EU) published recommendations advising against the harmonisation of domestic plug and socket systems in the EU.
In electrical and safety engineering, hazardous locations are places where fire or explosion hazards may exist. Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. Electrical equipment installed in such locations can provide an ignition source, due to electrical arcing, or high temperatures. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations.
NEMA connectors are power plugs and receptacles used for AC mains electricity in North America and other countries that use the standards set by the US National Electrical Manufacturers Association. NEMA wiring devices are made in current ratings from 15 to 60 amperes (A), with voltage ratings from 125 to 600 volts (V). Different combinations of contact blade widths, shapes, orientations, and dimensions create non-interchangeable connectors that are unique for each combination of voltage, electric current carrying capacity, and grounding system.
Magnet wire or enameled wire is a copper (Cu) or aluminium (Al) wire coated with a very thin layer of insulation. It is used in the construction of transformers, inductors, motors, generators, speakers, hard disk head actuators, electromagnets, electric guitar pickups and other applications that require tight coils of insulated wire.
A brushed DC electric motor is an internally commutated electric motor designed to be run from a direct current power source and utilizing an electric brush for contact.
In electrical engineering, electrical safety testing is essential to make sure electrical products and installations are safe. To meet this goal, governments and various technical bodies have developed electrical safety standards. All countries have their own electrical safety standards that must be complied with. To meet to these standards, electrical products and installations must pass electrical safety tests.
Premium efficiency, when used in reference to specific types of Electric Motors, is a class of motor efficiency.
Film capacitors, plastic film capacitors, film dielectric capacitors, or polymer film capacitors, generically called film caps as well as power film capacitors, are electrical capacitors with an insulating plastic film as the dielectric, sometimes combined with paper as carrier of the electrodes.
Condition monitoring of transformers in electrical engineering, is the process of acquisition and processing of data related to various parameters of transformers so as to predict and prevent the failure of a transformer. This is done by observing the deviation of the transformer parameters from their expected values. Transformers are the most critical assets of electrical transmission and distribution system. Transformer failures could cause power outages, personal and environmental hazards and expensive rerouting or purchase of power from other suppliers. Transformer failures can occur due to various causes. Transformer in-service interruptions and failures usually result from dielectric breakdown, winding distortion caused by short circuit withstand, winding and magnetic circuit hot spot, electrical disturbances, deterioration of insulation, lightning, inadequate maintenance, loose connections, overloading, failure of accessories such as OLTCs, bushings, etc. Integrating the ‘individual cause’ monitoring allows for monitoring the overall condition of transformer. The important aspects of condition monitoring of transformers are:
References
- ↑ "NEMA Insulation Classes". www.engineeringtoolbox.com.
- ↑ E. Alfredo Campo (ed.), Selection of polymeric materials: how to select design properties from different standards William Andrew, 2007 ISBN 0-8155-1551-0 page 170
- 1 2 3 International Electrotechnical Commission Standard 60085 Electrical Insulation- Thermal Evaluation and Designation, 3rd edition, 2004 ,page 11 table 1
- ↑ NEMA standard MG-1 Motors and Generators
- ↑ M. A. Laughton, D. F. Warne (ed), Electrical engineer's reference book, 16th edition Newnes, 2003 ISBN 0-7506-4637-3, page 7-3
- ↑ Donald G. Fink and Wayne H. Beaty (ed), Standard Handbook for Electrical Engineers, Eleventh Edition, Mc Graw Hill, 1978, ISBN 0-07-020974-X, page 7-12
- ↑ "Understanding IEC Appliance Insulation Classes: I, II and III". Fidus Power. 6 July 2018. Archived from the original on 17 February 2020. Retrieved 16 October 2018.