Interactive labs, calculators & simulators
49 browser-based tools across 11 disciplines. Filter by category, difficulty, audience, or status.
Arc Flash Concept Simulator
Explore how voltage, available fault current, working distance, clearing time, equipment configuration, and protection features influence conceptual incident energy and arc-flash boundary behavior.
Box Fill Calculator
Calculate NEC 314.16 box fill volume by entering conductors, looped conductors, internal cable clamps, device yokes, and equipment grounding conductors — with a box cross-section visualization, category breakdown, five preset scenarios, and a knowledge-check quiz.
Breaker Trip Unit Simulator
Set LSIG trip unit parameters on a live TCC and see how Long-Time, Short-Time, Instantaneous, and Ground-Fault regions respond to load and fault current — with six presets, five industry-specific Design Lab scenarios, a side-by-side Compare tab, and an Event Simulator.
Busway / Bus Duct Insulation & Connection Test Report
A NETA-compliant field test record for busway and bus duct acceptance and maintenance testing — capturing insulation resistance (MΩ) and connection resistance (μΩ) per section, wire configuration-aware IR test matrices, a visual bus map with section status tracking, and print-to-PDF output.
Commercial Load Build-Up Calculator
Build a commercial service load from the ground up across 13 occupancy types — stacking general lighting, receptacle, motor, HVAC, sign, and special loads with NEC Article 220 demand factors applied per category, with a load stack chart, what-if scenarios, load balance analysis, and calculation trace.
Conductor Ampacity & Wire Sizing Calculator
Size conductors under NEC Article 310 — pick load, material, insulation, and terminal rating, then apply ambient temperature correction and bundling adjustment factors in the correct code order to land on a compliant AWG/kcmil size.
Conductor Derating & Adjustment Explorer
Apply temperature correction and bundling adjustment factors to conductor ampacity in the correct NEC order — with table selection (310.16 vs. 310.17), neutral CCC determination, terminal temperature cap, and parametric charts showing how each factor shifts the final allowable ampacity.
Conduit Fill Calculator
Add conductors by wire type, AWG, and insulation to any of seven raceway types — get live NEC Chapter 9 fill percentage, pass/fail status, and auto-select the smallest compliant conduit size, with a step-by-step trace and design challenge mode.
Continuous Load Sizing Basis Calculator
Enter continuous and noncontinuous load amperes for a branch circuit, feeder, or service and get the NEC sizing basis — with the 125% multiplier applied correctly, the 100%-rated assembly exception explained as a listing condition, and edition-specific notes for 2017, 2020, and 2026.
CT / PT and Relay Measurement Simulator
Trace how current and voltage transformers scale primary quantities for relay inputs — then inject load, fault, and ground fault currents to see how overcurrent, differential, and directional relays respond in real time.
Differential Protection Simulator
Simulate 87T transformer and 87B bus differential protection — adjust slope, pickup, and harmonic restraint, then drive internal faults, external faults, and inrush to see the operate/restraint characteristic respond in real time.
Dwelling Unit Load Calculator
Calculate dwelling service load using all three NEC Article 220 methods — Standard (220.82 Part III), Optional (220.82), and Existing Dwelling (220.83) — with side-by-side comparison, service size ladder, and five preset scenarios including an undersized service case.
Equipment Grounding Conductor (EGC) Sizing Calculator
Size equipment grounding conductors from NEC Table 250.122 — with upsizing for derated phase conductors, parallel feeder configurations, raceway-as-EGC path evaluation, and a visual EGC vs. GEC distinction diagram.
EV Charger Branch, Feeder & Service Calculator
Size branch circuits, feeders, and service entrances for EVSE installations under NEC 625 — supporting Level 1, Level 2, and DC Fast charging with demand factor application and multi-unit feeder aggregation.
Fault Current & Short-Circuit Simulator
Model three-phase, SLG, LL, and DLG faults across a four-bus radial system using the per-unit method — with configurable source impedance, transformer, cable, and relay — and a clear statement of what a code-grade study includes that this educational tool does not.
General Lighting & Receptacle Branch-Circuit Calculator
Size general lighting and receptacle branch circuits under NEC Articles 210 and 220 — with occupancy VA/ft² lookup, custom VA entry, continuous-load factor, receptacle and dedicated-load configuration, and a circuit designer with self-test mode.
Generator Test Documentation
A NETA and NFPA 110 field test documentation tool for generator acceptance and maintenance testing — capturing generator and engine nameplates, load step measurements (0–100%), voltage and frequency tolerance validation, real-time trend charts (kW/Hz/V/I vs. time), visual and electrical checklists, and print-to-PDF output.
Generator, ATS & Emergency Power Sequence Simulator
Step through the full utility-loss-to-generator-transfer sequence — start delay, warm-up, ATS transfer, re-transfer, cooldown — with configurable timing parameters, a live one-line diagram, state machine view, and event timeline.
Grounding & Bonding System Visualizer
Visualize grounding and bonding current paths across service entrances, separately derived sources, generators, and UPS systems — with fault injection showing how grounding method and bonding connections control fault-current return paths.
Grounding Electrode Conductor (GEC) Sizing Calculator
Size the grounding electrode conductor from NEC Table 250.66 for service entrances and separately derived systems — with electrode-type sub-rules (250.66(A/B/C)), parallel conductor sets, material selection, and six preset configurations.
Harmonics & Waveform Distortion Lab
Build distorted waveforms by mixing harmonic orders 3 through 13, measure THD and K-factor in real time, and explore how VFDs, rectifiers, LED drivers, and office electronics each create distinct harmonic signatures.
HVAC & Refrigeration MCA / MOCP Interpreter
Read HVAC and refrigeration equipment nameplates correctly under NEC Article 440 — enter marked MCA and MOCP values, select your conductor and OCPD, and get an immediate pass/fail against both nameplate requirements with a live circuit visualizer and a side-by-side Article 440 vs. 430 comparison.
Industrial Sensor & Signal Simulator
Configure pressure, temperature, flow, level, and discrete sensors, select 4–20 mA or 0–10 V signal types, trace scaling to PLC raw counts, and simulate fault conditions including open wire, noise, and bad calibration.
LV Circuit Breaker Test Report
A NETA-compliant field test record for low-voltage power, air, insulated-case, and molded-case circuit breakers — covering contact wipe, insulation resistance, LSIG primary injection trip tests, coil minimum pickup voltage, functional checks, and control wiring IR, with JSON export and print-to-PDF output.
MCC Inspection & Test Documentation
A NETA-compliant MCC inspection and test record with a draggable 12-item visual/mechanical checklist, per-bucket unit schedule with lineup view, bus connection and insulation resistance tests, SCCR verification, deficiency tracking with severity and corrective-action workflow, and JSON export with print-to-PDF output.
Motor Branch-Circuit Conductor & OCPD Study Tool
Size branch-circuit conductors, overload protection, and OCPD for single-motor circuits under NEC Article 430 — with a live one-line diagram, motor starting current simulation, illustrative TCC, Table 430.52(C)(1) multiplier matrix, copper-vs-aluminum comparison, and self-test mode.
Motor IR / DAR / Polarization Index Test Record
A NETA and IEEE 43-aligned field test record for motor insulation resistance, DAR, and PI testing — with full motor nameplate capture, IEEE 43-2013 winding category minimums, automatic temperature correction to 40°C using Kt, timed audible interval prompts, and technician/reviewer dual signatures.
Motor Starting Simulator
Compare Across-the-Line, Reduced Voltage Auto-Transformer, Soft Starter, and VFD starting methods on live current, speed, and torque curves — with configurable HP, inertia, NEMA design class, and voltage from 208 V to 4160 V.
Multiple Motor Feeder & Service Calculator
Add multiple motors and optional non-motor loads to size a feeder conductor and feeder OCPD under NEC Article 430 — two distinct calculations (430.24 and 430.62) with FLC table lookups, a step-by-step trace, and six common-mistake guards built in.
MV Air Circuit Breaker Test
A NETA and IEEE C37.09-compliant field test record for medium-voltage air circuit breakers — covering insulation resistance (with PI and DAR options), contact and bolted connection resistance (μΩ), contact travel/gap/wipe, operating speed, pole spread and simultaneity, coil current/voltage, and deficiency tracking — with multi-record support, clone, JSON export, and print-to-PDF.
OCPD Sizing Calculator
Size overcurrent protective devices for general, continuous, and motor branch circuits under NEC 240.4 and 430.52 — with device-type selector, next-standard-size logic, conductor protection check, 100%-rated assembly exception, and seven preset scenarios illustrating common sizing traps.
One-Line Diagram Builder & Explorer
Build, edit, and explore single-line diagrams using standard power system symbols — with automatic energized-path tracing, load aggregation, connection mapping, and five preset system topologies.
Panelboard & Feeder Load Calculation
Build a multi-category panelboard or feeder load schedule with NEC Article 220 demand factors applied per category — general lighting, receptacles, kitchen, motors, HVAC, and more — then evaluate feeder conductor sizing and bus utilization.
PLC Ladder Logic Simulator
Run and step through ladder logic programs in the browser — toggle digital inputs, watch outputs and coils update rung-by-rung, trace the PLC scan cycle, and advance through Beginner, Intermediate, and Advanced scenarios.
Power Factor Correction Simulator
Add capacitor bank kVAR to a lagging-power-factor load and watch the power triangle, current, and illustrative utility penalty model update — with six real-world load scenarios and an over-correction demonstration.
Power Panel Insulation Resistance Test Record
A NETA-aligned insulation resistance test record for panelboards, switchboards, MCCs, and switchgear — with per-circuit IR readings, temperature correction, acceptance criteria from NETA ATS, NETA MTS, manufacturer, or custom thresholds, pre-test safety checklist, and JSON export with print-to-PDF output.
Power System Simulator
Model a three-phase or single-phase power system — configure source voltage, a transformer, and multiple loads, apply power factor correction, and see live phasor diagrams, voltage and current waveforms, and system metrics update in real time.
Power Transformer Simulator
Model a power transformer from 25 kVA to 10 MVA — adjust loading, impedance, power factor, tap position, and ambient temperature, then explore efficiency curves, thermal loading, voltage regulation, and fault behavior.
Protection Zone & Relay Scheme Explorer
Explore protection zones, relay responsibility areas, and scheme behavior across four system topologies — then drive fault scenarios including feeder faults, bus faults, transformer internal faults, backup operation, and breaker failure.
Protective Relay Coordination / TCC Visualizer
Plot upstream and downstream IEC IDMT relay, breaker, and fuse curves on a live TCC — then verify CTI margin, inject fault current, and step through the trip sequence using six preset coordination scenarios.
Protective Relay Test Record
A complete NETA-compliant protective relay test record for acceptance, maintenance, and commissioning — with dynamic relay element entry, calibrated test equipment logging, visual inspection checklist, deficiency tracking, safety controls documentation, and print-to-PDF output.
SCCR / AIC Fault Current Compliance Checker
Check assembly SCCR and device AIC ratings against available fault current — with a sensitivity analysis, equipment comparison explorer, step-by-step calculation trace, current-limiting fuse impact, and NEC code-logic walkthrough.
Service & Feeder Conductor Sizing Calculator
Size service entrance and feeder conductors under NEC Articles 215 and 230 — with continuous-load factor, ambient and bundling correction, material and terminal temperature cap, voltage drop, and a design challenge mode.
Substation & Switchgear Bus Configuration Explorer
Compare Single Bus, Double-Ended, Sectionalized, and Alternate Source topologies under normal operation and fault conditions — evaluate reliability metrics, model transfer types, and walk through six sequenced operations scenarios.
Switchgear Inspection & Test Record
A complete NETA-compliant switchgear inspection and test record covering 19 visual/mechanical checklist sections and 10 electrical test categories — with photo documentation, scored pass/fail results, dual technician and customer-representative signature blocks, a report readiness indicator, and print-to-PDF output.
Symmetrical Components & Fault Visualizer
Decompose unbalanced three-phase systems into positive, negative, and zero-sequence networks — then drive fault current through them and see every sequence quantity update in real time.
Transformer Vector Group & Polarity Visualizer
Visualize Delta-Wye, Wye-Delta, Delta-Delta, and Wye-Wye transformer connections with live phasor diagrams showing primary and secondary voltage relationships, phase shift, and polarity for balanced, unbalanced, and single-phase conditions.
Transformer Winding Resistance Test Report
A NETA and IEEE C57.152 field test record for transformer winding resistance — with a configuration wizard (Dyn/Ynd/Dd/Yyn presets, 1–33 tap positions), temperature correction to 75°C or 20°C using IEEE C57 constants, phase balance and deviation analysis, trend comparison against prior/factory test data, and print-to-PDF output.
Voltage Drop Calculator & Explorer
Calculate AC voltage drop for single- and three-phase circuits across five voltages and two conductor materials — with live parametric charts (drop vs. length, vs. current, vs. temperature), a copper-vs-aluminum comparison, conductor explorer, six quick presets, and a scenario lab.