![]() ![]() The available configurations are vertical conductors in a box (VCB), vertical conductors terminated in a barrier in a box (VCBB), horizontal conductors in a box (HCB), vertical conductors in open air (VOA) and horizontal conductors in open air (HOA). Step 6: Determine the electrical equipment box/electrode configuration. The box correction factor does not affect incident energy results as significantly as other parameters, such as the box/electrode configuration. Assume the worst-case scenario for motor control centre (MCC) starter buckets or other power distribution equipment where box sizes may vary. typical).Īgain, field measurements are not required. Step 5: Determine the box correction factor (shallow vs. ![]() The gap does affect incident energy calculations, but is not as significant as other parameters. Verify with the manufacturer’s shop drawings, if available. ![]() Use typical data no field measurements are required, unless atypical electrical equipment is identified. If you increase the gap from the default values, calculated incident energy will increase. Step 4: Determine gaps for electrical equipment.ĭetermine typical gaps and enclosure sizes based on system voltages and classes. The minimum recommendation is 8.0-cal/cm 2 arc thermal performance value (ATPV) arc flash PPE. Alternatively, the arc flash personal protective equipment (PPE) category method in CSA Z462, Workplace Electrical Safety, Table 6A, could be applied where the transformer is up to 300 kVA, depending on impedance. The guide says “sustainable arcs are possible, but less likely, in three-phase systems operating at 240 V AC nominal or less with an available short-circuit current less than 2,000 A.” For 208-V AC three-phase electrical equipment at 2,000 A, the available fault current is typically a 45-kVA or higher transformer size and all related panelboards will require calculations. Step 3: Address three-phase electrical equipment. For motor contributions less than or equal to 50 hp-and in some cases with client requirements for motors less than 200 hp-lump the motors. You need to consider single mode or multiple modes when determining both low (minimum) and high (maximum) bolted fault currents. This is different from strictly completing a short circuit analysis. Step 2: Determine the system modes of operation. Configure the ‘software arc flash module’ before starting calculations. With this data, create a digital single line diagram model in power engineering software. ![]() Start with an available single line diagram, use specific electrical equipment data sheets and request electrical utility fault data for each service. Step 1: Collect the system and installation data. When calculating arc flash hazard incident energy, IEEE 1584-2018 requires the following steps to be completed. With both documents, an electrical engineer can substantiate any assumptions/parameter selections and/or disclaimers they may include in reports to their clients. IEEE 1584.1 was first published in 2013-as a companion to IEEE 1584, Guide for Performing Arc-Flash Hazard Calculations-to ensure such incident energy analysis studies were completed correctly, with a detailed report aligned with good engineering practices. This is unfortunate, as the guide explains steps to complete a power system study, calculate arc flash incident energy and boundary and generate a quality engineering report. Not many electrical engineers across Canada seem to be aware of Institute of Electrical and Electronics Engineers (IEEE) 1584.1, Guide for the Specification of Scope and Deliverable Requirements for An Arc-Flash Hazard Calculation Study in Accordance with IEEE Std 1584. ![]()
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