Knowing the hazard levels in your system is a crucial step in managing arc flash risk. An arc flash hazard calculation study can tell you exactly what the hazard is and under what conditions. It will help you identify activities with high arc flash risk so you can focus on them first.
When an arc flash hazard calculation study is performed according to IEEE Standard 1584 there are some additional advantages. Because fault levels and time-current characteristics need to be determined for the arc flash hazard calculations, equipment evaluation and protective device coordination (evaluation of selectivity) can be added with ease. This way an arc flash hazard calculation study turns into a total system check-up checking co-ordination between protection devices for example.
Legislation for Arc Flash
There is a clear requirement in the recognition of arcing as a hazard and a need to undertake a suitable and sufficient risk assessment on recognised hazards. In Europe there’s currently no legal obligation to consider it, but current standards are perfectly suited to include arc flash hazard in a work safety program.
Arc Flash Energy Calculation Methods
Calculation of arc flash hazard levels is done using the IEEE standard 1584-2002: IEEE Guide for Performing Arc Flash Hazard Calculations. For three-phase systems of voltages between 208 V and 15 kV a calculation method is available that uses empirically derived formulas. For voltages higher than 15 kV a theoretical method is used that has been developed by Ralph Lee.
To create an accurate model of the power system the first step is to collect data. From a single line diagram all components that need to be modelled – for example cables, transformers, switchgear and protective devices – are identified and listed in data collection forms. Getting the actual data of each of the components can be completed by your personnel or on-site by Engineering Power Solutions.
Arc Flash Study Report
The arc flash hazard calculation study will result in a report with all results and recommendations. The report includes:
Full power system modeling data, as required for the arc flash hazard calculation study
Fault levels calculated using the IEC 60909 method for equipment evaluation
Fault levels calculated using the ‘comprehensive’ method for arc flash hazard calculation
Coordination of protective devices, including time-current characteristics diagrams
Tabulated arc flash calculation results for all locations
Arc flash labels in PDF format for all locations
Risk Reduction Solutions (Click here) – using your study results to reduce arc flash risk.
Training & Implementation (Click here) – the final steps to get your workers up to speed and working more safely.
Peter Rawson - Operations Director