ElectraSim 2.0: Challenge Mode, the Diagnosis Lab, Guided Circuits and the Electrical Toolbox

ElectraSim 2.0 is about one thing: turning a wiring drawing into something you can learn from, practise on, and hand over. The canvas and the simulation engine were already there — 115 modelled components, live Live/Neutral/Earth path tracing, protective devices that trip because the circuit says they should. What 2.0 adds is everything around that engine: structured modes that tell you whether you got it right, guided templates that teach while you wire, a fault lab you can break things in, compliance reporting, and a reference toolbox that lives next to the simulator on the website.

This post is the complete tour. Everything linked below is live today, free, with no account and no tracking.

Open ElectraSim 2.0 →

v2.0.1 Maintenance Update: We’ve polished the welcome popup with seamless animations, unified the “Coming Soon” badges across navigation and footer, optimized page loading speeds so preview graphics load only when needed, and fine-tuned menu interactions across the site.

v2.0.2 Update: The simulator comparison has been rebuilt as a current research bench with task filters, instrument plots, and linked first-party evidence.

v2.0.3 Update: The Circuit Guide is now a complete route through the subject — 20 circuit walkthroughs, 22 component anatomy pages (16 with interactive cutaways), 8 tool pages and a 37-term glossary — and there is a start-here post that walks you through it from beginner level to pro.

v2.0.4 Update: A correctness pass over the guided circuits and the guide’s plumbing. The validator no longer reports an “over-rated breaker” on circuits whose cable was never undersized, the eight affected templates now declare the conductor and device rating they actually wire, every learner-facing device name uses the rating in front of you (canvas, Inspector, Zs panel, mini-EIC and trip dialog agree), the homepage snippet fits its budget, and the app’s links into the guide point at the routes the guide serves.

1. Three learning modes, judged by the real simulator

Free-build is where most simulators stop. ElectraSim 2.0 ships three structured modes, and all three are judged by the same simulation engine the canvas uses — not by a script that checks whether you clicked the right pixel.

Challenge Mode — build to a mission

You get a goal (a protected lamp, a momentary doorbell, an RCBO-fed socket) and high-level outcome requirements — deliberately without a step-by-step construction recipe, so you still have to figure the circuit out yourself. Rules are checked on topology, not coordinates: any electrically equivalent wiring passes. Three progressive hints are there if you want them, your normal circuit is snapshotted and restored exactly when you leave, and every verdict is plain English.

Diagnosis Lab — find the fault they hid

The generator breaks a working circuit on purpose and hands it to you with a vague symptom: “the hallway light is dead.” You investigate, pick your diagnosis, repair it, and get scored. Exercises are deterministic from a seed — copy the seed, paste it, get the identical circuit — which is also what makes the whole lab reproducible in a classroom. Three difficulty profiles scale the scenario shape.

Two honesty details worth knowing, because they took real work:

• The console no longer prints the answer. The simulator’s own trip messages used to name the injected fault outright — in Diagnosis mode those messages are now withheld by index at the point they are pushed, so you still see the consequences a diagnostician reasons from, never the giveaway.
• The panel re-derives the symptom live. The briefing text is regenerated from your actual circuit as you work, so if clearing one fault reveals another, the panel says the symptom has changed instead of describing a circuit that no longer exists.

Ohmageddon — opt-in punishment

For when Diagnosis is too comfortable: compound faults that deliberately mask each other (verified by an electrical-equivalence gate, so the masking is real, not cosmetic), a misleading-symptom modifier, limited hints and a timer. It is electrically honest — never unfair — and every brutal run is shareable by seed.

2. A deterministic generator underneath

All three modes sit on a seeded, deterministic circuit generator: same seed, same circuit, same faults, every time. It went through a generator stress lock before the modes shipped — tens of thousands of generated scenarios checked for solvability, reachability and honesty — and the diagnosis pipeline is verified across 269,808 fault injections. If a scenario says a fault is findable, it is.

3. Guided Circuits — templates that teach

Eight ready-made circuit templates land on the canvas at full fidelity — protected lamp, one-way and two-way staircase lighting, a momentary doorbell, an RCBO-protected socket, an RCD earth-fault demo, a Pro SPD consumer unit and more — each with an in-app checklist that ticks items off as your circuit actually satisfies them. A further ten Pro guides cover three-phase, control and distribution circuits. Guided Circuits are deliberately unlinked from Challenge Mode: one is a teacher, the other is an examiner.

4. The Fault Lab

Manual fault injection moved into the Inspector as a first-class Fault Lab: open circuits, short circuits, reversed polarity, earth faults, arc faults and smooth-DC residual (the kind that blinds a Type AC/A/F RCD — only a Type B trips). Inject a fault on a component or a wire, and the canvas shows the consequence with live fault effects — flickering flame markers on overheated runs, sever cues on broken conductors — while the right protective device responds, or pointedly fails to. An active-faults command centre lists everything currently injected so nothing lurks forgotten.

5. Pro standards, compliance and reporting

• Standards gating checks your circuit against the active standard before the simulation runs, explains what violates what, and records a teacher’s override as an audit event.
• Zs / disconnection-time checks (BS 7671 Reg 411.3 style) with earth-arrangement awareness.
• A mini EIC-style report export renders your circuit’s schedule of devices into a printable title-block layout — clearly stamped as educational output, never a certificate.
• The default standard is now International (IEC), with region presets (UK, EU, US, AU, PK and more) one click away, and the Student/Pro selector is honest about what Pro unlocks.

6. The Electrical Toolbox on the website

The simulator’s reference shelf lives at electrasim.com/tools/ — free, no sign-up, no tracking:

• Voltage Drop Calculator with a live source-to-house scene that reacts to the verdict, real circuit presets, and shareable result URLs.
• Cable Size Calculator v2 — rebuilt around one question: what is the smallest cable that keeps the voltage drop inside the limit I chose? It draws the answer as an isometric source → cable → load run whose thickness, heat and appliance behaviour follow the maths. It also sizes the hot cable, not the cold one (conductor temperature is an input, defaulting to 70 °C — a correction worth ~20% on every previous figure), quotes the design current so voltage-drop-only never masquerades as ampacity, and prints a tidy spec sheet.

Both run their maths in one shared, unit-tested engine, checked against BS 7671 and IEC 60364 limit sets.

7. A workbench that got out of your way

The app shell was rebuilt around speed: a ⌘K command palette for every action, a menu redesigned as a command hub, portable profile backups (export/import your whole settings profile as a file), an in-app docs overlay bridged to the website guides, and redesigned Guided Circuits and Settings windows. Two interactive tours walk you through it — a Student tour that builds your first circuit with you, and a Pro tour covering standards, diagnostics and the fault tooling. Both advance by watching what you actually do, not by clicking “Next”.

8. Correctness fixes that matter

• Conductor-bypass validation — a circuit with an unwired Neutral pair on an FCU used to score 100%. A per-device port-connectivity check now catches bypassed conductors and unwired components, with RCD/RCBO imbalance wording where it matters.
• Compound-fault honesty — a masking verdict now replaces the optimistic proposal row instead of merging with it, so the rage summary cannot claim a compound that does not exist.
• Tier escalation is honest by burden (faults to find never decrease, hints are never restored), not by modifier count.
• Cable sizing sized cold cables — fixed (see §6). The length slider no longer rounds 500 m to 501 m, and a rejected input is marked stale instead of showing a stale result as current.

9. Accessibility, icons and dark mode

Full keyboard navigation, reduced-motion support throughout, a colour-blind-safe canvas preset, and a real dark theme across the app and the entire website. Every emoji pictograph in the simulator and on the site was replaced with inline vector artwork — identical on every OS and browser, no emoji-font dependency, no missing-glyph boxes. As part of that work the icon table was moved out of the initial bundle, so the app’s first payload actually got smaller while gaining the icons.

10. Web platform work

Strict per-route Content-Security-Policies, security headers everywhere, 301 redirects for every moved page (the old /blog/ release notes now land on /updates/, and the retired Explorer URLs land on the Explore page), unique per-post social cards, a site-wide instant search (⌘K on the site too), an “Open Circuit” 404, and an installable offline PWA for the simulator itself.

About Explore: the 3D historical laboratory is being rebuilt for v2.1. The old URLs redirect cleanly, and /explore/ now says exactly that — coming soon, no teasers pretending otherwise.

11. What’s new in v2.0.1: Bug fixes & user experience refinements

Version 2.0.1 brings helpful visual polish, smarter navigation, and bug fixes across both the website and the circuit simulator:

• Instant search category filters: Clicking any category filter (Calculators, Guides, Articles, Updates) inside the search dialog now filters the list immediately even before you start typing.
• Continuous glowing release popup: Re-engineered the animated release text with a seamless gradient sweep so the glow animates continuously without stopping or stuttering.
• One tip per visit on calculators: The Voltage Drop Calculator now greets you with a single, clear tip when the page loads, rather than continuously cycling tips in the background. Refreshing the page brings up another helpful tip.
• Direct circuit loading from guides: When clicking a circuit guide link from the website, ElectraSim now asks if you’d like to load the circuit onto your workbench immediately.
• Balanced tutorial walkthroughs: Centered the initial tutorial step on both mobile and desktop screens, fixed a step transition so no steps are skipped, and stopped the walkthrough from spotlighting the same palette tile twice — after you place the Live terminal, the spotlight now moves on to the Neutral terminal so the next step is always obvious.
• Guided wiring with on-canvas arrows: The Student tour’s wiring step now draws animated arrows straight onto the canvas — Live → L and N → Neutral — so it shows you exactly which ports to click instead of relying on text alone.
• Centered command palette: The Ctrl+K command palette used to open at the top-left of the window; it now opens centred in your viewport.
• Centered settings window: Adjusted the settings panel so it stays neatly centered on your screen with a sensible width — no more full-width stretch on wide monitors — and cleaned up the About tab.
• Neat component labels: Adjusted label padding and font sizes so component names and ratings fit inside their boxes without overflowing.
• Seamless page transitions & faster prefetching: Enabled instant view transitions and background prefetching for rapid navigation across articles, guides, and tools.
• New interactive calculator guide: Published an in-depth visual guide on how to calculate cable sizes and voltage drop interactively.

12. What’s new in v2.0.2: a rebuilt comparison bench

The comparison route now works as a research instrument rather than a static product grid. It maps nine tools across practical wiring, numeric analysis, guided teaching, sharing, offline work and start-up friction. A filterable matrix, selectable profiles, radar plot and average-fit bars make the trade-offs visible without pretending that one simulator wins every job.

The evidence is kept close to the claim: the page records the official product, documentation, pricing, classroom and repository pages reviewed on 4 September 2026. When a public source does not document a capability, the bench says Not confirmed instead of inferring a negative. Open the comparison bench or go straight to the simulator guide for ElectraSim’s own scope.

13. What’s new in v2.0.3: the guide has a front door

The guide used to be a good reference with no obvious way in. Twenty circuit walkthroughs, twenty-two components and eight tools were all there, and none of them told you which one to open first. Two things change that.

A start-here post. How to Use the ElectraSim Guide: Beginner to Pro is the route: what to read at each level, how to read a walkthrough, when to open a component page instead, and how to tell when you are ready to move up. It ends where the reading stops being useful — Challenge Mode, the Diagnosis Lab and Ohmageddon, judged by the same engine the canvas runs on.

A guide you can take apart. The component pages now carry two views: the outside of the real part, with hotspots pinned to its actual geometry, and — for sixteen of them — a cutaway showing the mechanism. On an MCB that is the latch, solenoid, arc chute and bimetal strip; on an RCD it is the summation transformer and trip solenoid. One click on a marker fills the side rail; the picture does not move.

The circuit walkthroughs each end with their own link into the app, so a walkthrough you have just read opens pre-built on the canvas. The glossary catches the 37 terms those walkthroughs actually use, linked both ways, so a definition is one click away and the way back is another.

Behind the scenes the guide also got the plumbing a reference site needs: every guide page now carries its own social card, so a link pasted into a chat shows that page rather than the site’s generic image, and the breadcrumb trail on each page is marked up as well as rendered.

14. What’s new in v2.0.4: the guided circuits stop arguing with themselves

Every Guided Circuit is checked by the same validator the app runs, and that validator had a bug of its own. The over-rated-breaker check read the first attached wire and, when that wire had no declared size, assumed 1.5 mm² — the size of a lighting circuit. On a template that wires a 2.5 mm² socket radial or a 10 mm² EV supply, the check reported a fault that did not exist: six to eight of the twenty guided circuits failed validation out of the box, and the EV circuit was credited with a 7.6 % voltage drop it never had.

The check now resolves conductor size honestly: a declared size on the wire wins, then the smallest size an endpoint explicitly declares, then a 2.5 mm² default — and it takes the worst case across every wire attached to the load rather than stopping at the first one. A cable that declares no size at all is a warning that names what could not be checked, not a blocking error, and the recommendation names the next size up the ladder. Eight templates were corrected to declare what they wire, from the D-curve 16 A contactor circuit to the EV charger whose isolator, RCBO and charge point all now declare the same 10 mm² run. All twenty templates validate cleanly under the default standard.

The same pass fixed how the app names things. A device’s catalogue label carries a default rating — “RCBO (32A 30mA)” — while the circuit in front of you may be a 20 A device. The canvas, Inspector, Zs panel and mini-EIC certificate had been corrected to the real rating; the trip dialog, the trip narration and the smooth-DC blinding message had not, so the same breaker was two different devices depending on where you looked. All of them now use the instance rating.

Two smaller corrections round it out. The homepage title and description were over the length Google actually displays, so the snippet clamp was shipping a title ending in a bare “&” and a description cut mid-sentence — the copy now fits, and the clamp drops dangling punctuation and connector words so ten other pages stop ending on “and” or “to the”. And the app’s docs panel was linking to guide anchors that stopped existing when the guide became a route table; those links, and the counts beside them, now point at pages that are really there — checked by a new test that compares the app’s URLs against the Astro routes.

ElectraSim 2.0 is live now at electrasim.com/app — nothing to install, nothing to sign up for, and it keeps working offline after the first visit.

New here? Start with the Student tour (offered on first launch), then try a Guided Circuit — the protected lamp is a five-minute build. When that feels comfortable, the Diagnosis Lab is where the real learning starts.