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Electrical Safety
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. Some types of electrical safety tests include: * dielectric withstand test (also called a hipot test) *insulation resistance test (IR test) *earth continuity test * leakage current test Electrical safety tests are described in various national and international standards. Electrical safety tests Dielectric voltage withstand test A dielectric voltage withstand test (also known as a hipot test) is done by applying a voltage higher than operating voltage Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after the commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is divided into a wide range of different fields, including computer engineering, systems engineering, power engineering, telecommunications, radio-frequency engineering, signal processing, instrumentation, photovoltaic cells, electronics, and optics and photonics. Many of these disciplines overlap with other engineering branches, spanning a huge number of specializations including hardware engineering, power electronics, Electromagnetism, electromagnetics and waves, microwave engineering, nanotechnology, electrochemistry, renewable energies, mechatronics/control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Safety Standards
Electrical safety is a system of organizational measures and technical means to prevent harmful and dangerous effects on workers from electric current, arcing, electromagnetic fields and static electricity. History The electrical safety develops with the technical progress. In 1989 OSHA promulgated a much-needed regulation in the General Industry Regulations. Several standards are defined for control of hazardous energy, or lockout/tagout. In 1995 OSHA was successful in promulgation of regulations for utility. In 1994 were established Electrical Safety Foundation International non-profit organization dedicated exclusively to promoting electrical safety at home and in the workplace. * Standard 29 CFR 1910.269 – for electric power generation, transmission, and distribution, contained comprehensive regulations and addressed control of hazardous energy sources for power plant locations Standards are compared with those of IEEE and National Fire Protection Association. Lightni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hipot
In electrical engineering, a dielectric withstand test (also pressure test, high potential test, hipot test, or insulation test) is an electrical safety test performed on a component or product to determine the effectiveness of its insulation. The test may be between mutually insulated sections of a part, or energized parts and ground. The test is a means to qualify a device's ability to operate safely during rated electrical conditions. If the current through a device under test is less than a specified limit at the required test potential and time duration, the device meets the dielectric withstand requirement. A dielectric withstand test may be done as a factory test on new equipment, or may be done on apparatus already in service as a routine maintenance test.Paul Gill (2009), ''Electrical Power Equipment Maintenance and Testing'', Second Edition, CRC Press, 1574446568, page 459 Voltage withstand testing is done with a high-voltage source A voltage source is a two-term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leakage Current
In electronics, leakage is the gradual transfer of electrical energy across a boundary normally viewed as insulating, such as the spontaneous discharge of a charged capacitor, magnetic coupling of a transformer with other components, or flow of current across a transistor in the "off" state or a reverse-polarized diode. In capacitors Gradual loss of energy from a charged capacitor is primarily caused by electronic devices attached to the capacitors, such as transistors or diodes, which conduct a small amount of current even when they are turned off. Even though this off current is an order of magnitude less than the current through the device when it is on, the current still slowly discharges the capacitor. Another contributor to leakage from a capacitor is from the undesired imperfection of some dielectric materials used in capacitors, also known as ''dielectric leakage''. It is a result of the dielectric material not being a perfect insulator and having some non-zero cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), work needed per unit of Electric charge, charge to move a positive Test particle#Electrostatics, test charge from the first point to the second point. In the SI unit, International System of Units (SI), the SI derived unit, derived unit for voltage is the ''volt'' (''V''). The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in a Electric generator, generator). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. Since it is the difference in electric potential, it is a physical Scalar (physics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulation (electric)
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 electrical conductor, 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 Nonmetal (chemistry), non-metals. A perfect insulator does not exist because even the materials used as insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as electrical breakdown, and the voltage at which it occurs is called the breakdown voltage of an insulator. Some materials such as glass, Electrical insulation paper, paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conformance Testing
Conformance testing and also known as compliance testing or type testing, is testing or other activities that determine whether a process, product, or service complies with the requirements of a specification, technical standard, contract, or regulation. It is an element of the more general conformity assessment. Testing is often either logical testing or physical testing. The test procedures may involve other criteria from mathematical testing or chemical testing. Beyond simple conformance, other requirements for efficiency, interoperability, or compliance may apply. Conformance testing may be undertaken by the producer of the product or service being assessed, by a user, or by an accredited independent organization, which can sometimes be the author of the standard being used. When testing is accompanied by certification, the products or services may then be advertised as being certified in compliance with the referred technical standard. Manufacturers and suppliers of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator (electricity)
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 electrical conductor, 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 Nonmetal (chemistry), non-metals. A perfect insulator does not exist because even the materials used as insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as electrical breakdown, and the voltage at which it occurs is called the breakdown voltage of an insulator. Some materials such as glass, Electrical insulation paper, paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Protective Equipment
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemical, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. ''Protective clothing'' is applied to traditional categories of clothing, and ''protective gear'' applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit. The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megger Group Limited
Megger Group Limited (also known as Megger) is a British manufacturing company that manufactures electronic test equipment and measuring instruments for electrical power applications. Megger is known for its Insulator (electrical), electrical insulation testers. It supplies products related to the following areas: Electrical cable, cable fault locating, ground (electricity), earth/ground testing, low Electrical resistance, resistance measuring, power quality, electrical wiring, insulation testers, multimeters, Portable Appliance Testing, portable appliance testers, clamp-on meters, current transformers, etc. History Over the years there were several companies whose names were associated with Megger. Evershed & Vignoles Sydney Evershed (1858–1939) and Ernest Vignoles (1865–1948) bought the instrument section of Golden Trotter (where they both worked) and founded Evershed & Vignoles Limited on 5 February 1895. However, it is likely that the origins of Megger can be tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 60601
IEC 60601 is a series of technical standards for the safety and essential performance of medical electrical equipment, published by the International Electrotechnical Commission. First published in 1977 and regularly updated and restructured, as of 2011 it consists of a general standard, about 10 collateral standards, and about 80 particular standards. General standard The general standard ''IEC 60601-1 – Medical electrical equipment – Part 1: General requirements for basic safety and essential performance'' – gives general requirements of the series of standards. 60601 is a widely accepted benchmark for medical electrical equipment and compliance with IEC60601-1 has become a requirement for the commercialisation of electrical medical equipment in many countries. Many companies view compliance with IEC 60601-1 as a requirement for most markets. This standard does not assure effectiveness of a medical device. In the US, evidence of effectiveness is required by the FDA and con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
