How This App Works

The left sidebar is always visible — switch tabs and your inputs stay. Tweak a breaker on this tab, see the diagram update on the Topology tab, the score update on Analytics, the design pass-rate change on the Challenge tab. Everything is live.

Tabs at a Glance

  • Topology — One-line diagram, click breakers
  • Operations — Switching log, sequence narrative
  • Analytics — Live charts: load distribution, source utilization
  • Design Challenge — System scores your design vs. requirements
  • Scenario Lab — Conceptual end-state puzzles
  • Reliability — Compare all five topologies head-to-head
  • Learn Mode — Quiz, key concepts

Live Snapshot

Get Going

Pick a configuration in the sidebar. Then:

  • Open and close breakers
  • Trip a source from the Quick Scenarios
  • Watch the Analytics tab while you do it
  • Try a Design Challenge — see if your design passes

Why Bus Configuration Matters

The arrangement of buses, breakers, and sources determines who keeps the lights on when something fails. A single bus is cheap and fragile. A main-tie-main is the workhorse. A double-ended with auto-transfer is gold standard for critical load. Sectionalizing limits blast radius without adding redundancy. Alternate-source schemes add a backup but introduce a transfer-time gap. Use the Design Challenge tab to find out which one actually fits a given requirement set.

Educational Disclaimer: Conceptual topology explorer for learning. Not switching authority. Not protection coordination software. Not code-compliance validation. Scores shown are relative educational scores, not calculated availability or engineering-grade reliability. Always follow facility procedures and applicable codes (NEC, NFPA 70E, NFPA 99, NFPA 110, IEEE standards) with a qualified engineer.

Topology View

Main-Tie-Main
Energized De-energized Warning/Parallel Open/Isolated
Insight: Select a topology and start operating breakers.

About This Configuration

Educational Disclaimer: Conceptual explorer. Does not model protection, relay settings, fault currents, arc flash, or real-time conditions. Not switching authority.

Operations & Switching

Use sidebar controls to operate. Breaker and source events are logged here.

Insight: Use the sidebar to operate.

Switching Log

Operational Flexibility

Transfer Mode: Manual
Educational Disclaimer: Conceptual explorer. Does not model protection, relay settings, fault currents, arc flash, or real-time conditions. Not switching authority.

Live Analytics

Charts update in real time as you change sidebar inputs. Scores are educational/relative, not engineering-grade.

Educational Score Gauge

Relative conceptual score, not calculated availability.

Load Distribution by Section

Source Utilization

Energized vs De-energized Loads

Cost vs Educational Score — All Topologies (your current config is highlighted)

Event History (last 20 breaker/source events)

Educational Disclaimer: Conceptual explorer. Does not model protection, relay settings, fault currents, arc flash, or real-time conditions. Not switching authority.

Design Challenge

Pick a challenge. Use the sidebar to design your system. The system grades your answer against the requirements — automatically.

Choose a Challenge

Your Current Design

Requirements Check

Score

--
Score

Design Hints

Note: Design grading is conceptual. Real substation design requires load flow studies, short-circuit analysis, protection coordination, arc flash assessment, and code review by a licensed professional engineer.

Scenario Lab

Each scenario is a conceptual end-state puzzle. Use sidebar controls to reach the goal state. This does not model switching sequence, interlocks, or protection coordination.

Active Scenario

Objectives

Evaluation

Use sidebar controls to attempt the scenario. Click "Evaluate" when ready.

Note: These are conceptual end-state puzzles. They do not represent proper switching orders, safety procedures, or protection scheme operation. Real switching requires written procedures, safety grounding, lockout/tagout, and authorized personnel.

Educational Score Comparison

Relative educational scores for comparing topologies. Not calculated availability or MTBF. Your current configuration is highlighted.

Educational Scores

Single Bus

Lowest Score

One source, one bus. Cheap, fragile.

Main-Tie-Main

High Score

Two sources, tie breaker. Workhorse.

Double-Ended

Highest Score

Each source carries full load. Auto-transfer ready.

Sectionalized

Medium

One source, split bus. Limits blast radius.

Alternate Source

Medium

Standby waiting. Transfer time is your cost.

Tradeoff Matrix

ArrangementSourcesTieMaint. FlexTransfer$ (rel.)
Note: Scores are relative educational rankings to compare topologies conceptually. Real reliability analysis requires failure rate data (IEEE 493/Gold Book), load flow, and Monte Carlo simulation or analytical methods.

Learn Mode

Why This Matters

Bus topology decides who keeps power when something fails. It's an architectural decision with daily operational consequences.

Common Mistakes

  • Assuming a normally-open tie provides redundancy without a transfer scheme
  • Forgetting sectionalizing doesn't add a source
  • Treating "alternate available" as "automatic transfer"
  • Not sizing the surviving source for full load in a transfer scenario
  • Ignoring the transfer-time gap for critical loads
  • Paralleling sources through a tie without sync-check and protection coordination

What to Notice

  • How many sections survive a source trip
  • Whether tie closure restores or parallels
  • "Backup available" vs "backup connected"
  • Source loading after transfer (overload risk)
  • Whether maintenance isolates one section or kills everything

At-a-Glance

  • Single: One source, one bus. Any fault or maintenance = full outage.
  • MTM: Two sources + tie. Normal split-bus, manual or auto transfer via tie.
  • Double-Ended: MTM + full-rated sources + automatic transfer capability.
  • Sectionalized: One source, split bus. Limits fault exposure.
  • Alt Source: Standby source + transfer scheme. Transfer time gap is the cost.
“A normally-open tie is a promise, not a transfer. Something still has to close it — and something has to decide it is safe to.”

Quiz Challenge

Your Score

0 / 8 correct

Educational Disclaimer: Conceptual explorer. Does not model protection, relay settings, fault currents, arc flash, or real-time conditions. Not switching authority.