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Milsoft Utility Solution’s Arc Flash Analysis software facilitates faster and easier assessment of arc flash hazards and electrical incident analysis. Identify and analyze high risk arc flash areas in your electrical power system with greater flexibility by simulating and evaluating various mitigation methods in your arc flash study.
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Arc Flash Review:Requirements, Results, Issues,
and Strategies
Keith Mullen, P.E.
Arc Flash Review
WindMil & LightTable Requirements Consensus Standards Analysis Methodology Sample Results Issues Uncovered Hazard Reduction Strategies Assessment Integration Questions
Arc Flash Review: Requirements
Accurate Connectivity Model Up-to-Date Source Impedances Complete Equipment & Device Definitions Add Transformer Protection Accurate Construction Codes Establish Device Links to LightTable Analysis Parameters Based on Operating Practices
Arc Flash Review: Standards
NFPA 70EHazard/Risk Categories
Hazard/RiskCategories
Calculated Arc Energy(Cal/cm2) (J/cm2)
0 1.2 5.01 4.0 16.72 8.0 33.53 25.0 104.64 40.0 167.4
> 4 > 40.0 >167.4
Arc Flash Review: StandardsIEEE Standard 1584 Method Voltages from 208V to 15,000V Frequency from 50Hz to 60Hz Bolted fault currents from 700A to 106,000A Grounding of all types and ungrounded Equipment enclosures of commonly available sizes Gaps between conductors from 13mm to 152mm Faults involving three phases
Arc Flash Review: StandardsIEEE 1584
Factors for Equipment and Voltage Classes
System Voltage (kV) Equipment Type Typical Gap Between
Conductors (mm) Distance Factor
0.208 - 1
Open Air 10-40 2.000
Switchgear 32 1.473
MCC & Panels 25 1.641
Cable 13 2.000
> 1 - 5
Open Air 102 2.000
Switchgear 13-102 0.973
Cable 13 2.000
> 5 - 15
Open Air 13-153 2.000
Switchgear 153 0.973
Cable 13 2.000
Arc Flash Review: Analysis Methodology
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results Lee method is the most conservative IEEE method is more conservative than
ARCPRO at low-end fault values IEEE method and ARCPRO yield consistent
results at various fault levels Parameters in the NESC Table 410.1 must align
with equipment specifications and operating practices
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Requirements
Urban System Feeder breaker and fuses clearing faults Limited variations in faults and clearing timesRural System Larger variety and layers of protective devices Significant variations in faults and clearing times
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results
Arc Flash Review: Sample Results Transformer protection is critical to arc
clearing time System impedance can influence calculated
hazard levels on transformer low-side Line devices upline of transformer fuse can
reduce arc clearing time Arc flash results can be significantly impacted
by transformer impedance
Arc Flash Review: Issues & Strategies
Arc Flash Review: Issues & Strategies
Arc Flash Review: Issues & Strategies
Arc Flash Review: Issues & Strategies
Arc Flash Review: Issues & Strategies
Arc Flash Review: Integration Operating procedures and clothing systems
should align with arc flash results Hazard levels should be re-evaluated with
changes to system configuration and fault levels Adjustments to coordination scheme should
include an arc flash assessment Planning studies should include the impact of
recommendations on hazard levels
Arc Flash Review: Questions
Keith Mullen Senior Engineer & Project Manager - Nashville
R. W. Beck, Inc.tel 615.431.3212 fax 615.824.7570 131 Mir Parkway, Suite 300 Hendersonville, TN 37075
