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Test And Tagging
In electrical safety testing, portable appliance testing (PAT, PAT inspection or redundantly as PAT testing) is a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of earthing (grounding) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested. Other countries have similar procedures, for example, testing of equipment according to ''DGUV Vorschrift 3'' in Germany. Purpose Health and safety regulations require that electrical appliances are safe and maintaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planned Maintenance
The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, and residential installations. Over time, this has come to include multiple wordings that describe various cost-effective practices to keep equipment operational; these activities occur either before or after a failure. Definitions Maintenance functions can defined as maintenance, repair and overhaul (MRO), and MRO is also used for maintenance, repair and operations. Over time, the terminology of maintenance and MRO has begun to become standardized. The United States Department of Defense uses the following definitions:Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms * Any activity—such as tests, measurements, replacements, adjustments, and repairs—intended to retain or restore a fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Continuity Test
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar energy is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BS 7671
British Standard BS 7671 "Requirements for Electrical Installations. IET Wiring Regulations", informally called in the UK electrical community "The Regs", is the national standard in the United Kingdom for electrical installation and the safety of electrical wiring in domestic, commercial, industrial, and other buildings, also in special installations and locations, such as marinas or caravan parks and medical locations In general, BS 7671 applies to circuits supplied at nominal voltages (Uo) up to and including 1000 volts AC or 1500 volts DC. The standard therefore covers the Extra Low Voltage (ELV) range (0-50V AC, 0-125V DC), and the Low Voltage (LV) range (50-1000V AC, 125-1500V DC). The frequencies covered for AC are 50 Hz, 60 Hz, and 400 Hz, used in the UK for houses, offices, and commerce. It did not become a recognized British Standard until the publication of the 16th edition in 1992. The standard takes account of the technical substance of agreements re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2010 Section 2
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surge Protector
A 'surge protector'' (or spike suppressor, surge suppressor, surge diverter, surge protection device (SPD) or transient voltage surge suppressor (TVSS) is an appliance or device intended to protect electrical devices from voltage spikes in alternating current (AC) circuits. A voltage spike is a transient event, typically lasting 1 to 30 microseconds, that may reach over 1,000 volts. Lightning that hits a power line can give a spike of over 100,000 volts and can burn through wiring insulation and cause fires, but even modest spikes can destroy a wide variety of electronic devices, computers, battery chargers, modems and TVs etc, that happen to be plugged in at the time. Typically the surge device will trigger at a set voltage, around 3 to 4 times the mains voltage, and divert the current to earth. Some devices may absorb the spike and release it as heat. They are generally rated according to the amount of energy in joules they can absorb. some company have surge protection devic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surge Protector
A 'surge protector'' (or spike suppressor, surge suppressor, surge diverter, surge protection device (SPD) or transient voltage surge suppressor (TVSS) is an appliance or device intended to protect electrical devices from voltage spikes in alternating current (AC) circuits. A voltage spike is a transient event, typically lasting 1 to 30 microseconds, that may reach over 1,000 volts. Lightning that hits a power line can give a spike of over 100,000 volts and can burn through wiring insulation and cause fires, but even modest spikes can destroy a wide variety of electronic devices, computers, battery chargers, modems and TVs etc, that happen to be plugged in at the time. Typically the surge device will trigger at a set voltage, around 3 to 4 times the mains voltage, and divert the current to earth. Some devices may absorb the spike and release it as heat. They are generally rated according to the amount of energy in joules they can absorb. some company have surge protection devic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Insulation
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. A perfect insulator does not exist because even 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 the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appliance Classes
Appliance classes (also known as protection 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. Class 0 These appliances have no protective-earth connection and feature only a single level of insulation between live parts and exposed metalwork. If permitted at all, Class 0 items are intended for use in dry areas only. A single fault could cause an electric shock or other dangerous occurrence, without triggering the automatic operation of any fuse or circuit breaker. Sales of such items have been prohibited in much of the world for safety reasons, for example in the UK by Section 8 of The Low Voltage Electrical Equipment (Safety) Regulations 1989and New Zealand by thElectricity Act A typical exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Appliance Test
In electrical safety testing, portable appliance testing (PAT, PAT inspection or redundantly as PAT testing) is a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of earthing (grounding) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested. Other countries have similar procedures, for example, testing of equipment according to ''DGUV Vorschrift 3'' in Germany. Purpose Health and safety regulations require that electrical appliances are safe and maintained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protective Earth
An earthing system (UK and IEC) 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. In addition to electric power systems, other systems may require grounding for safety or function. Tall structures may have lightning rods as part of a system to protect them from lightning strikes. Telegraph lines may use the Earth as one conductor of a circuit, saving the cost of installation of a return wire over a long circuit. Radio antennas may require particular grounding for operation, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appliance Classes
Appliance classes (also known as protection 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. Class 0 These appliances have no protective-earth connection and feature only a single level of insulation between live parts and exposed metalwork. If permitted at all, Class 0 items are intended for use in dry areas only. A single fault could cause an electric shock or other dangerous occurrence, without triggering the automatic operation of any fuse or circuit breaker. Sales of such items have been prohibited in much of the world for safety reasons, for example in the UK by Section 8 of The Low Voltage Electrical Equipment (Safety) Regulations 1989and New Zealand by thElectricity Act A typical exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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