IEEE 1584:2018 pdf free download – IEEE Guide for Performing Arc-Flash Hazard Calculations
Deliverables of the arc-flash hazard analysis calculation are the arc-flash boundary and the arc-flash incidentenergy at defined working distances from the arcing source at the selected locations in the electrical system.The results of the study document the incident energy analysis and may be used by workers as part of anoverall electrical safety risk assessment.
6.2 Step 1: Collect the system and installation data
A significant effort in performing an arc-flash hazard study is the collection of electrical system data. Evenfor a facility with nominally up-to-date single-line diagrams, time-current curves, and short-circuit model ona computer, the data collection portion of the study may take about half of the effort. Even for new facilities,field verification of the single-line diagrams and protection settings is necessary to verify the integrity ofdocumentation of the power system.Facility workers who are familiar with the electrical system and itssafety-related work practices may be able to assist or perform this part of the study.Refer to lEEE Std 1584.1for further information on system data required for an arc-flash hazard analysis.
While the data required for this study is similar to data collected for typical short-circuit and protective-devicecoordination studies it goes further in that all low-voltage distribution and control equipment within the scopeof the study up through its sources of supply must be included.
Collect information to perform incident energy calculations on electrical equipment that is likely to requireexamination, adjustment, servicing, or maintenance while energized.This could include equipment such aslow- and medium-voltage switchgear，medium-voltage plug-in connectors，motor starters,motor controlcenters(MCCs), switchboards, switchracks, panelboards, separately-mounted switches and circuit breakers,ac and dc drives, power distribution units (PDUs), uninterruptible power supplies (UPS), transfer switches,industrial control panels, meter socket enclosures, etc.
The study process begins with a review of available single-line diagrams and electrical equipment site andlayout arrangement with people who are familiar with the site.The diagrams should be updated to show thecurrent system configuration.
Electrical system studies should have an up-to-date single-line diagram(s).The single-line diagrams includeall alternate feeds.
Follow applicable industry standards for performing short-circuit studies. See Clause 2 for examples ofindustry standards.
Obtain the available fault current and X/R ratio that represents the source. For transformers, generators,large motors, and switchgear, collect relevant nameplate data such as voltage/voltage ranges or tap settings,ampacity, kilowatt or kilovoltamperes, first cycle (momentary or close and latch) and/or interrupting currentrating,impedance or transient/subtransient reactance data.Because information regarding box (enclosure)size and electrode configuration may be needed for more detailed calculations,it may be necessary to takemeasurements if possible or collect other data such as nameplate information or device catalog numbers thatwill allow for relevant equipment enclosure dimensions and configurations to be estimated.
Next, collect conductor and cable data along with its installation (routing and support method,in magneticraceway-steel conduit or non-magnetic raceway-aluminum conduit, etc.) for all electrical circuits between the power source and the distribution and control equipment that is part of the study. This information is needed forthe calculation of impedances. See IEEE Std 551 for information on how to perform short-circuit calculations.
Data from instrument transformers (current transformers and voltage transformers) and protective-device datathat is part of the study must be collected. The data should be collected from sources such as the nameplateandor time-current curves. If nameplate data is not accessible, data may be available in specifications or inrecent maintenance test reports. In any case, the user should verify data is still up to date by checking with theowner ‘s representative and, if necessary, by checking in the field. In some cases, a field inspection is requiredto determine the types and ratings of fuses actually installed, as well as the settings of circuit breaker trip unitsandor the settings of protective relays. Protective devices that have not been properly maintained may haveincreased fault clearing time, thereby increasing the incident energy.