Addressing the surge environment.
The Institute of Electrical and Electronics Engineers, IEEE, has produced a set of standards known as the “trilogy” to address the surge environment, characterize surges, and define surge testing in low-voltage AC power circuits. The following standards constitute the trilogy.
- IEEE C62.41.1, “Guide on the Surge Environment in Low-Voltage (1000 V and less) AC Power Circuits”
- IEEE C62.41.2, “Recommended Practice on characterization of Surges in Low-Voltage (1000 V and less) AC Power Circuits”
- IEEE C62.45, “Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000 V and Less) AC Power Circuits”
In addition IEEE has produced the following standards for the application and testing of SPDs.
- IEEE C62.47-1992, “IEEE Guide on Electrostatic Discharge (ESD): Characterization of the ESD Environment”
- IEEE C62.48, “Guide on Interactions Between Power System Disturbances and Surge-Protective Devices”
- IEEE C62.62, “Test Specifications for Surge-Protective Devices (SPDs) for Use on the Load Side of the Service Equipment in Low-Voltage (1000 V and Less) AC Power Circuits”
- IEEE C62.72, “Guide for the Application of Surge-Protective Devices for Low-Voltage (1000 V or Less) AC Power Circuits”
These standards have been developed from many years of scientific research and are recognized by American National Standards Institute (ANSI). They are intended for use primarily by surge equipment manufacturers and provide valuable reference for consulting engineers that specify surrge protection devices (SPDs).
Guide on the Surge Environment in Low-Voltage (1000 V and less) AC Power Circuits.
This guide, the first in the trilogy, provides readers with a comprehensive information on surges, the environment in which they occur and is a reference for the second document of the trilogy. The surge environment is described using:
- Three location categories (C, B or A) according to their position from the building service entrance.
- Level of exposure to major sources of surges: lightning and load switching.
- Representative waveforms of surge voltages and surge currents are described for each category.
This guide should not be used as a testing document to define performance, survivability or any other related test criteria. Any statement that a SPD “meets the requirement of” or “is certified to”, this document is inappropriate and misleading.
Recommended Practice on characterization of Surges in Low-Voltage (1000 V and less) AC Power Circuits.
This guide, the second in the trilogy, presents recommendations on the selection of surge waveforms, amplitudes of surge voltages and currents used to evaluate equipment immunity and performance of SPDs. Two recommended “standard” waveforms are used as a simplified representation of the surge environment:
- 0.5µs/100kHZ ringwave
- 1.2/50/8-20µs combination wave
Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000 V and Less) AC Power Circuits.
This guide, the third in the trilogy, focuses on surge testing procedures (using the simplified waveform representations) for obtaining reliable measurements and enhancing operator safety. The intent is to provide background that can help determine whether equipment or a circuit has adequate ‘withstand’ capability.
- Signal and data lines are not addressed in this document.
- The document does not indicate withstand levels that might be assigned to specific equipment.
- An important objective of the document is to call attention to the safety aspects of surge testing.
- Underwriters Laboratories, Inc. uses these guidelines as a reference in their performance and safety testing of SPDs.
IEEE Guide on Interactions Between Power System Disturbances and Surge-Protective Devices
This guide applies to surge-protective devices (SPDs) manufactured to be connected to 50 Hz or 60 Hz ac power circuits rated at 100–1000 V rms. It describes the effects on SPDs of power system disturbances occurring in these low-voltage ac power circuits. The disturbances are not limited to surges. The effects of the presence and operation of SPDs on the quality of power available to the connected loads are described. The interaction among multiple SPDs on the same circuit is also described. This guide discusses both voltage and current surges. The current surges discussed in this guide are the result of voltage surges. Current surges that are solely the result of load changes and do not result in voltage increases, such as a short circuit, are not discussed in this guide.
An SPD’s primary purpose is to provide surge protection. Devices discussed in this guide contain at least one nonlinear component for diverting surge current and/or dissipating surge energy, such as a metal oxide varistor (MOV), silicon avalanche diode (SAD), thyristor, or spark gap. Uninterruptible power supplies (UPSs), ferroresonators, motor-generators, and filters containing only inductive and/or capacitive components are not considered SPDs in this guide.
IEEE Standard Test Specifications for Surge-Protective Devices (SPDs) for Use on the Load Side of the Service Equipment in Low-Voltage (1000 V and Less) AC Power Circuits
This standard applies to surge-protective devices (SPDs) intended to be installed on the load side of the service equipment connected to 50 Hz or 60 Hz alternating current (ac) power circuits rated at 1000 V (root mean squared [rms]) or less. Performance characteristics and standard methods for testing and rating are established for these devices, which may be composed of any combination of components. The tests in this standard are aimed at providing comparisons among the variety of surge-protective devices available.
IEEE Guide for the Application of Surge-Protective Devices for Low-Voltage (1000 V or Less) AC Power Circuits
The transient overvoltages or surge events that are described and discussed in this guide are those that originate outside of a building or facility and impinge on a power distribution system (PDS) through the service entrance conductors. Transient overvoltages or surge events that originate from equipment within a specific facility are not within the scope of this document.
This guide applies to surge-protective devices (SPDs) that are manufactured for connections to 50 Hz or 60 Hz ac power circuits that are rated between 100 V rms and 1000 V rms. This guide applies to SPDs that are specifically identified, labeled, or listed for connections on the load side of the service entrance main overcurrent protective device. This guide does not cover those SPDs identified, labeled, or tested as a secondary surge arrester intended for connections on the line side of the service entrance main overcurrent protective device. The SPDs covered in this guide are those manufactured for use in an association with electrical power distribution equipment such as load centers, motor control centers, panelboards, switchboards, switchgear, and end-use equipment installed in commercial and industrial facilities. This guide excludes SPDs associated with retail and consumer appliances and components for residential use.
The SPDs discussed in this guide contain at least one nonlinear component for either diverting surge currents and/or dissipating surge energy. Examples of such nonlinear components are metal-oxide varistors (MOVs), silicon avalanche diodes (SADs), spark gap tubes, or thyristors. Ferroresonators, motor-generators, uninterruptible power supplies, and filters containing only inductive or capacitive components are not considered SPDs in the guide.
IEEE Guide on Electrostatic Discharge (ESD): Characterization of the ESD Environment
The purpose of this guide is to describe the electromagnetic threat posed to electronic equipment and subassemblies by actual Electrostatic Discharge (ESD) events from humans and mobile furnishings. This guide organizes existing data on the subject of ESD in order to characterize the ESD surge environment. This guide is not an ESD test standard. An appropriate ESD test standard should be selected for equipment testing. The manufacturing, handling, packaging, and transportation of individual electronic components, including integrated circuits, are not discussed, and this guide does not deal with mobile items such as automobiles, aircraft, or other masses of comparable size. ESD results in a sudden transfer of charge between bodies of differing electrostatic potentials. In this guide, the term ESD includes charge transfer whether or not an arc occurs or is perceived.
ESD phenomena generate electromagnetic fields over a broad range of frequencies, from direct current (dc) to low gigahertz. The term ESD event includes not only the discharge current, but also the electromagnetic fields and corona effects before and during a discharge. In this guide the intruder is often a human, but it may be any object that is moved, such as a chair, an equipment cart, a vacuum cleaner, or the equipment victim itself, whether or not it is in conductive contact with a human. The equipment victim is usually a fabricated electronic equipment or subassembly and is generally, although not necessarily, at local electrostatic ground potential.
The equipment victim may be the receptor to which the discharge takes place from the intruder; less frequently, the equipment victim may be the intruder. Alternatively, the equipment victim may be affected by the electromagnetic fields generated by a discharge between an intruder and a receptor. Receptors and intruders that may not themselves are equipment victims include furniture such as metal chairs, carts, tables and file cabinets, as well as other electronic equipment.
This guide discusses and cites references that describe the ways in which a body builds up charge and the characteristics of discharge currents and fields. Descriptions and references are also given for electrical equivalent circuits to be used in understanding and simulating the discharge current between intruder and receptor masses. Publications that are specifically referenced in the text of the guide are listed in the Section 3, while Section 9 cites additional publications in both ESD and related areas.
Most of the work that has been published in connection with actual ESD is related to discharges from humans, usually grasping or in association with a metal object. Far less published data exists for discharges from humans without metal objects, and from mobile furnishings, and virtually no data exists for discharges from human torsos or clothing. For this reason, primary emphasis is placed on discharges from humans with associated metal objects, with some additional material relating to ESDs from mobile furnishings. All discharges are assumed to take place in an air environment.
Finally, all of the published time-domain data on which this guide relies were taken using instrumentation with either a 400 MHz or a 1 GHz bandwidth.
IEEE Std 1100™-2005
IEEE Recommended Practice for Powering and Grounding Electronic Equipment
This document presents recommended design, installation, and maintenance practices for electrical power and grounding (including both safety and noise control) and protection of electronic loads such as industrial controllers, computers, and other information technology equipment (ITE) used in commercial and industrial applications.
IEEE Std. 142-2007
IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems
The problems of system grounding, that is, connection to ground of neutral, of the corner of the delta, or of the midtap of one phase, are covered. The advantages and disadvantages of grounded vs. ungrounded systems are discussed. Information is given on how to ground the system, where the system should be grounded, and how to select equipment for the ground of the neutral circuits. Connecting the frames and enclosures of electric apparatus, such as motors, switchgear, transformers, buses, cables, conduits, building frames, and portable equipment, to a ground system is addressed. The fundamentals of making the interconnection of a ground conductor system between electric equipment and the ground rods, water pipes, etc., are outlined. The problems of static electricity— how it is generated, what processes may produce it, how it is measured, and what should be done to prevent its generation or to drain the static charges to earth to prevent sparking—are treated. Methods of protecting structures against the effects of lightning are also covered. Obtaining a low-resistance connection to earth, use of ground rods, connections to water pipes, etc., are discussed. A separate chapter on electronic equipment is included.
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See the origial article at: http://www.nemasurge.org/ieee-standards-for-spds/