An Electrical Service Power Quality Study (often called a Power System Study or Electrical System Analysis) is a comprehensive engineering evaluation of a facility’s electrical distribution system. It examines how electrical power flows through the system and evaluates safety, reliability, and efficiency.
These studies are critical for designing, upgrading, troubleshooting, and maintaining electrical systems in industrial, commercial, and institutional facilities.
Purpose of a Power Quality Study
The main goals of an electrical service power study are to:
- Ensure Safety
- Protect people and equipment from hazards like arc flash incidents, electrical fires, and equipment failures.
- Verify Equipment Ratings
- Confirm that components (breakers, transformers, cables, etc.) can handle the maximum fault current and normal operating loads.
- Improve Reliability
- Prevent unplanned downtime by identifying weaknesses or bottlenecks in the electrical system.
- Meet Code & Standards
- Compliance with NEC (National Electrical Code), NFPA 70E, IEEE, and OSHA requirements.
- Optimize Operations
- Improve system efficiency and potentially reduce energy costs.
Key Types of Studies Included
A complete power study usually consists of several sub-studies, often performed together:
Study Type | Purpose |
Short-Circuit Study | Calculates available fault current at each point in the system to verify equipment withstand and interrupt ratings. |
Protective Device Coordination Study | Ensures circuit breakers, fuses, and relays trip in the correct sequence to minimize outages. |
Arc Flash Hazard Analysis | Identifies potential arc flash energy levels and recommends appropriate PPE and safety boundaries. |
Load Flow Study | Analyzes power distribution under normal and peak conditions to ensure proper voltage levels and prevent overloads. |
Power Quality Study | Detects harmonics, voltage sags, and other issues that could damage sensitive equipment. |
Motor Starting Study | Evaluates system impact when large motors start up to avoid voltage dips or instability. |
Process of Conducting a Power Study
- Data Collection
- Gather one-line diagrams, equipment specifications, utility data, and operating conditions.
- Modeling the Electrical System
- Use specialized software such as ETAP, SKM PowerTools, or EasyPower to build a digital model of the facility.
- Perform Analyses
- Run the appropriate calculations for each sub-study.
- Recommendations
- Provide adjustments, equipment upgrades, or operational changes to improve safety and reliability.
- Documentation
- Deliver a report that includes updated one-line diagrams, results, and compliance recommendations.
When a Power Study is Needed
- New facility design – before construction to ensure proper equipment sizing and protection.
- Major upgrades or expansions – when adding new machinery or loads.
- After utility changes – if the available fault current changes significantly.
- Periodic safety reviews – especially arc flash studies, which NFPA 70E recommends updating every 5 years or after major system changes.
- Post-incident analysis – after an outage or electrical failure to determine root cause.
Benefits
- Protects personnel with accurate arc flash boundaries and PPE requirements.
- Prevents costly downtime by reducing cascading failures.
- Avoids equipment damage by ensuring ratings are adequate.
- Meets insurance and regulatory requirements for high-risk facilities like hospitals, data centers, and industrial plants.
- Improves system performance and power quality.
Contact us today to find out if your company is in need of a power quality study.