Improving Electrical Safety Through Comprehensive Arc Flash Hazard Assessment
Electrical safety is a critical consideration wherever personnel work on or around energized electrical equipment. In medium-voltage systems, understanding the potential consequences of an arcing fault is particularly important for supporting safe maintenance practices and protecting personnel and equipment.
Power Projects successfully completed a comprehensive Arc Flash Hazard Study for an industrial facility in Maharashtra, India, focusing on its 33 kV Vacuum Circuit Breaker (VCB) panel.
The study used ETAP 22.5 / ETAP 24 and followed the methodology of IEEE 1584-2018, with PPE recommendations in accordance with NFPA 70E-2021.
The assessment provided the client with a technically validated basis for understanding arc flash hazards, determining incident energy, establishing arc flash boundaries and developing equipment-specific safety information.
Project Snapshot
- IndustryProcess Manufacturing
- LocationMaharashtra, India
- StudyArc Flash Hazard Assessment
- Voltage Level33 kV
- Area Covered33 kV Vacuum Circuit Breaker (VCB) Panel
- SoftwareETAP 22.5 / ETAP 24
- StandardsIEEE 1584-2018, NFPA 70E-2021
The study focused on evaluating the potential arc flash hazards associated with the 33 kV switchgear and determining the energy exposure that personnel could experience during an arcing fault.
Understanding the Client's Requirements
The client required a detailed engineering assessment of the electrical system to:
- Evaluate arc flash hazards associated with the 33 kV switchgear
- Develop a validated ETAP electrical network model
- Determine incident energy at working locations
- Calculate arc flash boundaries
- Recommend suitable PPE based on calculated incident energy
- Generate arc flash warning labels
- Improve electrical safety while complying with internationally recognised standards
These requirements called for a structured assessment covering the electrical network, fault conditions, arcing behaviour and personnel exposure.
The Engineering Challenge
An arc flash assessment requires more than simply determining the available fault current.
The study needed to consider the plant's electrical network and the conditions that influence the resulting arc flash hazard.
Key engineering challenges included:
- Accurately representing the plant electrical network in ETAP
- Evaluating multiple system operating modes that influence available fault current
- Calculating realistic arcing current rather than relying solely on bolted fault values
- Quantifying incident energy at the specified working distance
- Defining arc flash protection boundaries
- Identifying appropriate PPE levels
- Preparing equipment-specific safety information for operational use
The assessment also considered low-voltage loads and smaller switchgear in accordance with the assumptions defined for the study.
Engineering Approach
Power Projects developed a detailed digital model of the client's electrical distribution network using ETAP 22.5/24.
The model represented the 33 kV medium-voltage switchgear and associated electrical equipment based on the engineering information provided by the client.
The Arc Flash Hazard Study followed the methodology prescribed by IEEE 1584-2018. The assessment included the following key stages:
1System Operating Modes
The applicable system operating modes were identified to assess the conditions that influence the available fault current.
2Bolted Fault Current
The available bolted fault current was determined as the basis for the subsequent arc flash calculations.
3Arcing Current
The arcing current was calculated to represent the fault condition used for the arc flash assessment.
4Arc Duration
The arc duration was determined based on the operation of the applicable protective device.
5Incident Energy
The incident energy at the specified working distance was calculated to quantify the thermal exposure that personnel could experience during an arc flash event.
6Arc Flash Boundary
The arc flash protection boundary was established to define the safe approach distance during energized work activities.
7PPE Assessment
PPE recommendations were developed in accordance with NFPA 70E-2021, based on the calculated hazard levels.
8Arc Flash Warning Labels
Equipment-specific arc flash warning labels were prepared to communicate the calculated hazard information at the equipment location.
Key Engineering Activities
Electrical Network Modelling
A detailed ETAP model was developed and validated using the client-provided electrical system information.
The modelling represented the operating characteristics of the 33 kV switchgear and associated electrical equipment within the defined study scope.
Fault Current Assessment
Available fault currents were determined as the starting point for the arc flash calculations.
The assessment considered bolted fault current and subsequently determined the corresponding arcing fault behaviour required for the IEEE 1584-2018 methodology.
Incident Energy Analysis
Incident energy was calculated at the specified working distance.
These results provide an understanding of the thermal exposure that personnel could experience during an arc flash event and form the basis for the subsequent PPE assessment.
Arc Flash Boundary Determination
The study established the arc flash protection boundaries around the equipment.
These boundaries provide defined approach distances for personnel during energized work activities.
PPE Assessment and Equipment Labelling
Based on the calculated incident energy, appropriate PPE recommendations were developed in accordance with NFPA 70E-2021.
Arc flash warning labels were also prepared to provide equipment-specific safety information directly at the equipment location.
Value Delivered
The Arc Flash Hazard Study provided the client with a technically validated understanding of the electrical safety risks associated with its medium-voltage switchgear.
The study delivered:
- Improved awareness of arc flash hazards within the electrical network
- Quantified incident energy for maintenance activities
- Defined arc flash boundaries to support safe work practices
- PPE recommendations in accordance with NFPA 70E-2021
- Equipment-specific arc flash warning labels
- Support for compliance with IEEE 1584-2018 and NFPA 70E-2021
- Engineering documentation to support maintenance planning, safety training and risk mitigation
Software & Standards
Software
- Power System SimulationETAP 22.5
- Power System SimulationETAP 24
Applicable Standards
- IEEE 1584-2018Arc Flash Hazard Calculations
- NFPA 70E-2021Electrical Safety in the Workplace
Supporting Safer Electrical Maintenance
An effective Arc Flash Hazard Study provides more than a set of calculated values. It helps translate electrical system characteristics into practical safety information for personnel working on or around electrical equipment.
For this 33 kV electrical distribution system, Power Projects combined detailed ETAP network modelling with the IEEE 1584-2018 methodology to evaluate incident energy, arc flash boundaries and PPE requirements.
The resulting engineering assessment provides the client with a practical framework to support safer maintenance activities, improved electrical safety practices and standards-based risk mitigation.
Power Projects — Power System Engineering Expertise
Power Projects provides specialised engineering services in:
- Arc Flash Studies
- Harmonic Analysis
- Power Quality Studies
- Grid Compliance
- Protection Engineering
- Electromagnetic Transient Studies
Looking for Arc Flash Study Support?
Power Projects can support organisations requiring Arc Flash Hazard Assessments, incident energy calculations, arc flash boundary determination, PPE assessment and equipment labelling based on applicable engineering standards.
