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Surge Protection Device (SPD) for installation in a low-voltage distribution board. A surge protector (or spike suppressor, surge suppressor, surge diverter, [1] surge protection device (SPD), transient voltage suppressor (TVS) or transient voltage surge suppressor (TVSS)) is an appliance or device intended to protect electrical devices in alternating current (AC) circuits from voltage spikes ...
The National Electrical Code, 2008 edition. The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. It is part of the National Fire Code series published by the National Fire Protection Association (NFPA), a private trade association. [1]
The first electrical codes in the United States originated in New York in 1881 to regulate installations of electric lighting. Since 1897 the US National Fire Protection Association, a private non-profit association formed by insurance companies, has published the National Electrical Code (NEC). States, counties or cities often include the NEC ...
22 – Equalizer Circuit Breaker; 23 – Temperature control device, Heater; 24 – Volts per Hertz Relay (in some old analog applications, a 59 and an 81 device would be chained together as a 59/81 to implement the equivalent of V/Hz protection) 25 – Synchronizing or Synchronism-check Device; 26 – Apparatus Thermal Device, Temperature Switch
The United States National Electrical Code (NEC) specifies minimum acceptable wiring methods and materials for many states and municipalities. [2] It is sponsored by the National Fire Protection Association (NFPA) and has been periodically revised since 1897. Local jurisdictions usually adopt the NEC or another published code and then ...
IEC TR 62066 Surge overvoltages and surge protection in low-voltage a.c. power systems – General basic information IEC 62067 Power cables with extruded insulation and their accessories for rated voltages above 150 kV ( U m = 170 kV) up to 500 kV ( U m = 550 kV) – Test methods and requirements
The surge is defined by the Combination Wave Generator's open-circuit voltage and short-circuit current waveforms, characterized by front time, duration, and peak values. With an open circuit output, the surge voltage is a double exponential pulse in the form of k ( e − α t − e − β t ) {\displaystyle k(e^{-\alpha t}-e^{-\beta t})} .
National codes and site guides are meant to attain the common objectives of IEC 60364, and provide rules in a form that allows for guidance of persons installing and inspecting electrical systems. The standard has several parts: Part 1: Fundamental principles, assessment of general characteristics, definitions; Part 4: Protection for safety