Short-circuit faults can cause major disruptions, damage, and safety risks in electrical systems. When a fault occurs, your system’s ability to isolate and contain it—without tripping upstream devices unnecessarily—is what keeps operations running smoothly. That’s where Short-Circuit Coordination Studies come in. These engineering studies help ensure your protective devices operate in harmony, isolating faults efficiently and maintaining continuity of service.
At C&H Electric, we provide expert coordination studies that reduce risk, improve reliability, and ensure compliance with NFPA 70E, OSHA, and other critical standards.
A short-circuit coordination study evaluates how your electrical system’s protective devices (circuit breakers, fuses, relays) behave during a fault. It determines:
- How much fault current will flow
- How long it will take devices to clear the fault
- Whether those devices will act selectively—isolating only the affected portion of the system
This process involves:
- Short-Circuit Analysis – Identifies the magnitude of fault current at each system node
- Time-Current Coordination – Ensures device settings are staggered so upstream protection doesn’t trip first
- Arc Flash Evaluation – Helps determine PPE and label requirements
Required by NFPA 70E, OSHA 1910.303, and NEC 110.9 to ensure system safety and reliability.
Without proper coordination, multiple devices can trip during a single fault, shutting down more of your system than necessary. This can:
- Lead to unplanned production downtime
- Increase repair costs
- Damage equipment
- Create unnecessary safety risks
A properly executed short-circuit coordination study will:
- Improve fault containment
- Prevent nuisance tripping
- Increase worker safety
- Ensure regulatory compliance
- Support future system upgrades or expansions
- System Data Collection – Gather one-line diagrams, protective device specs, and utility data
- Modeling the Electrical Network – Create an accurate simulation in coordination software (like SKM or ETAP)
- Short-Circuit Calculations – Determine maximum and minimum fault levels
- Device Evaluation and TCC Analysis – Plot time-current curves to ensure proper sequencing
- Report and Adjustments – Recommend settings and provide documentation for compliance
- Labeling and Maintenance Plans – Apply results to arc flash labels and maintenance schedules
- Older systems with undocumented changes
- Improperly set or misaligned protective devices
- Integration of new systems like solar or generators
- Lack of selectivity causing full system trips
If your system hasn’t been studied in 5+ years or has undergone changes, it’s time for a new coordination study.
