What is a Protection Coordination Study?
A Protection Coordination Study analyzes and develops relay and device settings to achieve selective tripping. This means only the device closest to the fault operates, ensuring continuity of supply and minimizing damage.
We use Time-Current Characteristic (TCC) curves and advanced simulation software to fine-tune settings for relays, breakers, and fuses. Relay coordination curves such as Inverse, Very Inverse, Extremely Inverse, Definite Time, and Instantaneous are applied depending on fault-clearing requirements. Modern relays allow multiple settings for different operating modes, such as grid mode vs. islanding mode, ensuring protection under all system conditions.
How to Do Protection Coordination?
Protection coordination is carried out in several steps:
- Collect system data – including CT/PT ratings, breaker/fuse specifications, and load details.
- Perform short circuit analysis – to determine fault levels under different conditions.
- Select protective devices – relays, breakers, and fuses suitable for system requirements.
- Develop relay settings – using Time-Current Characteristic (TCC) curves to ensure selective tripping.
- Verify coordination – through simulation and adjustments to prevent nuisance tripping or delays.
- Document settings – with relay sheets, breaker parameters, and compliance reports.
What is Type 2 Protection Coordination?
Type 2 coordination (defined in IEC 60947-4-1) ensures that, after a short circuit, the protective device trips without causing permanent damage to the contactor or starter. This means:
- The motor starter can be put back into service after the fault.
- Only minor contact welding may occur, which is acceptable if easily separated.
- Equipment remains safe, reliable, and ready for reuse.
It is more stringent than Type 1 coordination, which allows damage requiring repair or replacement.
What is Protective Device Coordination?
Protective device coordination is the process of adjusting and matching settings of fuses, relays, and breakers so they work together effectively. The goal is selective coordination only the device nearest to the fault clears it, while upstream devices remain intact. This prevents system-wide outages, reduces arc-flash risk, and maintains continuity of service.
A Protection Coordination Study is the backbone of electrical safety and system reliability. We deliver precise studies to ensure faults are cleared selectively, safely, and without unnecessary disruption. Our power system studies optimize performance, safeguard equipment, and protect personnel.
Why Protection Coordination is Essential
When a fault occurs in a section of the power system, even the healthy network contributes to the fault current. This creates severe mechanical forces, thermal stresses, and risks to rotating equipment from unbalanced or negative sequence currents.
Without proper relay coordination, a minor fault can cascade into a system-wide failure, leading to costly shutdowns. Effective protection isolates the faulty section while keeping the rest of the network energized.
Importance of Relay Coordination
- Selectivity & Sensitivity
Ensures only the nearest protective device trips while maintaining sensitivity to real system conditions. - Safety
Reduces arc-flash and shock hazards by enabling quick fault isolation. - System Reliability
Prevents unnecessary downtime and ensures service continuity for critical operations. - Compliance with Standards
Meets IEC 60255, NEC, NFPA 70E, IEEE C37.113, IEEE 242 (Buff Book), and other global standards. - Device Coordination & Settings
Eliminates conflicts in relay/breaker settings that may cause nuisance tripping or failure to operate.
Scope of Our Protection Coordination Studies
For Existing Plants
- Review of CTs and PTs
- Power system data collection & validation
- Relay setting calculations and optimization
- Device coordination analysis
- TCC curve plotting and interpretation
- Fuse and circuit breaker rating verification
- Integration with short circuit & arc flash studies
- Relay settings for both minimum and maximum fault levels
For New Plants
In addition to the above:
- Selection of CTs, PTs, and relays
- Identification of required relay functions
- Development of complete protection schemes
Typical Devices Covered
- Inverse-time overcurrent relays
- Definite-time relays
- Fuses and MCCBs
- Motor protection relays
- Generator & transformer protections
- Feeder & busbar protections
- Transmission line protections
- Capacitor bank protections
Key Deliverables
- Comprehensive Protection Coordination Study Report
- Time-Current Characteristic (TCC) curves
- Recommended protection settings (tabular format)
- Relay setting sheets & breaker parameters
- Compliance and gap analysis report
- Practical recommendations (e.g., GOOSE communication for zone interlocking & selective tripping)
Optimize Your Protection System
With our Protection Coordination Studies, you gain:
- Safer operations
- Reduced downtime
- Compliance with global standards
- Optimized relay and breaker settings
We help your protection system work smarter, not harder ensuring reliability, safety, and continuity of power.
Looking for Protection Coordination Studies?
iFluids Engineering provides detailed Protection Coordination Studies that safeguard assets, reduce arc-flash risk, and maintain operational continuity.
Contact us for expert relay and breaker coordination support.