Live Parameter Updates
Changes in relay settings are reflected directly on the chart and Single Line Diagram.
ONLINE RELAY COORDINATION STUDY
(TCC Curves & Protection Coordination)
Over Current & Earth Fault Coordination • MCCB/Fuse Char. Curves • Fault Impedance • Motor Start & Base Load Curve
Unified Workspace
Everything Available on One Screen
Settings, interactive curves, equipment hierarchy and alarms remain visible together, helping engineers make faster and better-informed protection decisions.
Integrated Engineering View
Settings, curves, system hierarchy and alarm results stay visible together.
Faster Coordination Review
Compare upstream and downstream devices without repeatedly changing pages.
Clear System Context
Relate each protection curve to its physical position in the electrical network.
Simple Configuration
Structured Relay and System Settings
Configure the study without complicated navigation. Related parameters remain grouped in clean, readable panels.
All Major Parameters in a Simple Format
A clear, single-page interface provides complete Over Current and Earth Fault configuration. Enter CT ratios, IDMT curve families, plug settings, TMS values and multiple definite-time stages while retaining direct access to system-wide settings.
- Phase and earth-fault CT ratios
- IDMT curve family and plug setting
- TMS or operating delay
- DT Stage 1 and DT Stage 2
- Relay insertion, naming and enable controls
- Current range, time margin and study mode
- Source fault level and current capping
- Busbar, transformer, cable, fuse and MCCB modules
Interactive Protection Curves
Interactive Time–Current Curves
Precisely compare relay characteristics on a log–log chart and evaluate selectivity across the complete operating-current range.
Fast Visual Coordination
Users can isolate individual relays, display additional equipment curves, float the chart and drag curves for rapid setting evaluation.
Individual relay selectionAll-relay displayOver Current modeEarth Fault modeAdjustable current rangeAdjustable time rangeClear alarmsFloat chartDrag curvesFault-zone selection
X-axis: Current in amperes Y-axis: Operating time in seconds
Network Visualization
Dynamic Single Line Diagram
The dynamic Single Line Diagram visualises the protection network from source to load and keeps each curve connected to its actual electrical-system position.
- Source-to-load hierarchy
- Relay and equipment identification
- Transformer ratio and impedance
- Primary and secondary grounding
- Fault-current display
- Operating-time display
- Running and peak voltage
- Fault-location indication
Built-In Validation
Advanced Protection Alarm Intelligence
The platform automatically identifies protection risks and presents clear engineering warnings directly beneath the chart.
Minimum Time Margin
Detects coordination margins below the configured minimum value.
Reverse Coordination
Identifies an upstream device operating before downstream protection.
Curve Crossing
Highlights overlapping or intersecting protection characteristics.
Pickup Below Load
Warns when relay pickup is below the calculated maximum load current.
Motor Starting
Detects a relay that may operate during acceleration or re-acceleration.
Transformer Inrush
Compares relay trip time with transformer inrush duration.
Fuse & MCCB Selectivity
Checks coordination with downstream protective devices.
Fault-Zone Logic
Evaluates devices expected to respond in the selected network zone.
Earth-Fault Blocking
Recognises grounding or transformer configurations that block fault transfer.
Equipment Condition
Highlights through-fault or loading conditions requiring review.
Multi-Device Coordination
Fuse and MCCB Curves in One Click
Display fuse and MCCB curves instantly alongside relay characteristics. Compare operating times, intersections and coordination margins without switching between separate screens.
- Relay-to-fuse coordination
- Relay-to-MCCB coordination
- One-click curve visibility
- Equipment position linked to the SLD
- Local operating-current evaluation
- Coordination alarm support
Energisation Stability
Transformer Inrush Stability Check
Transformer inrush-current plotting verifies relay stability during energisation and raises an alarm when protection settings may cause unwanted operation.
Inrush Comparison
Compare relay operating time with transformer inrush current and duration.
Unsafe-Setting Alarm
Identify pickup, TMS or delay values that require correction.
Transformer FLCInrush multiplierInrush durationRelay operating timeMinimum marginVisual TCC check
Advanced Fault Simulation
Zone-Wise Earth-Fault Simulation
Evaluate earth-fault protection behaviour across multiple electrical-network sections with synchronized TCC and Single Line Diagram views.
Automatic zone mappingVector-group considerationNGR and grounding behaviourFault-current cappingActive or blocked relaysNo-Trip indicationZone-specific curvesFault voltage comparison
Print-Ready Documentation
Professional Engineering Reports
Generate structured reports for protection-setting review, coordination verification, calculations, approval and final project documentation.
Print-ready · Settings
All Settings Report
Consolidates basic parameters, transformer, busbar, cable, fuse and MCCB information and displays the total number of alarming conditions.
Print-ready · Coordination
Chart & Single Line Diagram
Presents the TCC chart, relay-setting summary and complete Single Line Diagram on one professional page.
Print-ready · Coordination
Relay Coordination Report
Compares relay operating times and coordination margins at multiple fault-current levels with colour-coded results.
Print-ready · Calculation
Fault-Voltage Calculation
Shows upstream source, transformer and cable impedance contributions, exact formulas, voltage drop and resulting fault voltage.
Print-ready · Calculation
Fault-Current Calculation
Presents source, transformer and cable impedance, total equivalent impedance and calculated three-phase short-circuit current.
Print-ready · Calculation
Running & Peak Voltage
Evaluates running-load and peak or motor-starting voltage using load current, motor-start current, power factor and impedance.
Project Continuity
Secure Cloud-Based Project Storage
Account-based cloud storage allows users to upload, search, load, download and delete study files from a compatible device, supporting project backup, recovery and continuation.
Upload StudySearch FilesLoad into ToolDownload BackupDelete FileSigned-In AccessCross-Device Continuation
Engineering Data Output
One-Click Printable Settings Export
Convert complete Over Current and Earth Fault relay settings into a structured Excel workbook for review, approval and sharing.
Complete Protection Settings in a Professional Format
The organised workbook includes protection device details, CT ratios, stage settings, curve families, pickup values, time delays and engineering remarks.
- Protection device ID
- Relay model and make
- Phase CT ratio
- Earth-fault CT ratio
- Stage 1 settings
- Stage 2 settings
- Stage 3 settings
- Curve family
- Pickup current
- TMS or delay
- Directional information
- Disabled-relay remarks
Transparent Results
Engineering Calculations You Can Review
Calculation reports present formulas, intermediate values and referenced impedances so results can be independently checked.
Source Impedance
Calculate source reactance from fault level and nominal voltage.
Transformer Impedance
Refer transformer impedance across voltage stages.
Cable R & X
Include cable resistance, reactance, length and parallel runs.
Fault Current
Calculate three-phase short-circuit current at the selected stage.
Fault Voltage
Evaluate voltage remaining at the faulted node.
Running Voltage
Determine running-load voltage and percentage drop.
Peak Voltage
Evaluate motor-start or peak-load voltage performance.
Zone Capping
Apply stage-specific through-fault current limits.
Designed for Protection Studies
Why Use RelayCoordination.com?
Complete Protection Study
OC, EF, relay, fuse, MCCB, transformer and motor-start evaluation.
Visual Engineering
Interactive curves and a dynamic Single Line Diagram remain synchronised.
Intelligent Validation
Automatic alarms identify inadequate settings and coordination problems.
Zone-Based Simulation
Study fault behaviour across multiple electrical-network sections.
Transparent Calculations
Detailed formulas and intermediate values support independent checking.
Professional Documentation
Generate printable charts, reports and structured settings sheets.
Cloud Project Handling
Save and continue studies through account-based online storage.
One-Click Export
Export complete protection settings into a printable Excel format.
From System Data to Final Report
Complete Study Workflow
- 1Create or upload a project
- 2Configure source and system data
- 3Add transformers, cables and devices
- 4Enter OC and EF settings
- 5Plot and compare TCC curves
- 6Run fault and voltage simulations
- 7Review alarms, reports and exports
Start Your Study
Start Your Relay Coordination Study Online
Develop protection settings, compare TCC curves, simulate faults, verify voltage performance and generate engineering reports from one integrated platform.
Use the study mode appropriate to your system complexity and engineering requirements.
Contact & Support
Questions About the Relay Coordination Tool?
For technical queries, use this contact form or email relay.coord@gmail.com.
RelayCoordination.com
Online relay coordination and protection engineering platform.