This is the legacy method and is used for one-line files created in EasyPower/EasySolv 8.0.2.200 series or earlier versions. The equation is as per the standard selected in the options and uses the equivalent bolted fault current through the device.

Equation: The arc current equation is used to calculate the remote currents.

This option is set to Ratio if the standard on the Arc Flash Hazard - Options tab is set to IEEE 1584-2018.įor the other standard options, EasyPower supports two different methods for determining the remote current through protective devices during an arc fault: A multiplier is applied to the calculation factor for VCBB and HCB electrode configurations not included in IEEE 1584-2002.

Use this option to enable consideration of the electrode configuration in IEEE 1584-2002 arc flash calculations. This applies to integrated and non-integrated calculation methods.Īdjust IEEE Calculation Factor Based on Electrode Configuration If this option is not selected, the library defaults or user-specified values are not used, and the enclosure size correction factor for IEEE 1584-2018 is set to 1. When selected, the arc flash calculations include the enclosure height, width, and depth (from either the library defaults or user-specified values) in the calculations. This option extends the low voltage DC equations to DC equipment in systems greater than 1 kV. Therefore, application of current-limiting fuse calculations to all enclosure sizes is a conservative approach.Īpply Low Voltage DC Equation to > 1 kV DC Equipment All other enclosure sizes (smaller or larger) resulted in reduced incident energy and arc flash boundary. enclosure size results in the highest incident energy and arc flash boundary. With the IEEE 1584-2018 equations, the 20 x 20 x 20 in. The current-limiting fuse calculations in IEEE 1584-2018 were based on testing performed using a 20 x 20 x 20 inch enclosure size. Therefore, the results for 18 inches will be slightly different from the results for 455mm. The default low voltage working distance in the program is 18 inches (which is equivalent to 457.2 mm). Note: The IEEE 1584 CL fuse equations provide incident energy at 455mm. When the 1584 CL Fuse Calculations are used for any bus, the Arc Flash Hazard Report shows the bolted fault current but not the arc current and the trip times, since these values are not used to determine the incident energy.

When the fault current is well below the current-limiting range of the fuse, the standard arc flash equations are used. The fuse equations are effective only when the fault current is high compared to the minimum fault current required for limiting current. This is applicable only for low voltage systems. Equations are available for classes L and RK1. This method calculates the let-through arc flash incident energy based on bolted fault currents and UL class of fuse. Use IEEE 1584 equations for current-limiting fuses to determine incident energy. See Defining PPE Levels for more information on customizing the levels.Īpply IEEE 1584 Current-Limiting Fuse Model Equationsįor the IEEE 1584-2018 standard, these calculations only apply when the electrode configuration is VCB. The levels are defined in the device library. You can select which standard you want to use to specify the level. If this check box is selected, the PPE description and level is displayed on the one-line and the Arc Flash Hazard report.

Select the standard on which you want to specify approach boundaries. This option applies only when the arc flash hazard Standard is set to use IEEE 1584-2018. Use this option to set a specific energy value for which you would like a distance calculated in addition to the normal arc flash boundary calculation. The value can be calculated in cal/cm 2 or Joules/cm 2 depending on the Display Incident Energy in option specified in the Short Circuit Options > Arc Flash Hazard settings. If the standard on the Arc Flash Hazard - Options tab is set to IEEE 1584-2018, you cannot change this. The boundary is at a distance at which the incident energy is less than or equal to 1.2 cal/cm 2. Figure 1: Advanced Arc Flash Options Option Descriptions Option

Approach boundary arc flash 2018