This simulator follows a branch circuit's complete path: breaker → conductor → receptacle/equipment → grounded return path. Adjust the source voltage, breaker rating, conductor material, length and AWG size, and the load type, then watch how each choice changes voltage drop, current, and the margin to trip.
• A 3D circuit model with a selectable-part inspector (click any component for its details) and a Reset Camera control, plus a Hide Labels toggle for the on-model callouts. • Simulation controls: source voltage (line-neutral), breaker rating, conductor length (one-way) and material (Copper or Aluminum), conductor size selectable from 14, 12, 10 or 8 AWG, load type (Resistive heater, Single-phase motor, or Electronic power supply/SMPS), an adjustable load setting, and a fault-severity multiplier. • Start/Pause/Step (+0.10 s) simulation-time controls, plus Export JSON to capture the full simulation state. • Live measurements panel reading out real-time circuit values at the selected point in the circuit. • Diagnostics & Learning, Guided Experiments and a Knowledge Check section, plus a Model Scope, Units, Equations reference panel documenting exactly what the model does and does not represent.
Voltage drop along a branch circuit depends on conductor resistance, which in turn depends on material (copper has lower resistivity than aluminum), cross-sectional area (AWG size — smaller AWG number means larger, lower-resistance conductor) and length (longer runs mean more resistance and more drop). The simulator lets you vary all three independently so you can see, for example, how upsizing a conductor or shortening a run recovers voltage at the load, and how the three different load types (a simple resistive heater, an inductive single-phase motor, and a nonlinear electronic power supply) draw and respond to that available voltage differently.
The fault-severity multiplier lets you inject a range of abnormal conditions to see how the model's protection responds and how the values recorded at your selected measurement point change. The circuit explicitly includes the grounded return path back to the source, not just the outbound conductor, which is essential to understanding why a bolted fault or an degraded ground connection changes fault current and protective device response — a branch circuit is a complete loop, not a one-way run.
Copper has lower electrical resistivity than aluminum, so a copper conductor of the same size and length has less resistance and less voltage drop. Conductor size (AWG) also matters — a smaller AWG number means a physically larger, lower-resistance conductor. The simulator lets you vary material, AWG size and length independently to see how each factor changes voltage drop at the load.
A resistive heater, a single-phase motor and an electronic power supply (SMPS) each respond to available voltage and draw current differently — a motor has inrush and reactive behavior, while a switching power supply presents a nonlinear, often distorted current draw. Comparing all three under the same conductor and voltage conditions shows how load type changes the circuit's real-world behavior beyond simple resistive assumptions.
A branch circuit is a complete loop — current has to return to the source through the grounded conductor just as it flows out through the ungrounded (hot) conductor. Including this return path is what lets the simulator correctly show how a bolted fault or a degraded ground connection changes fault current magnitude and how the breaker responds.
It lets you inject a range of fault conditions at adjustable severity to observe how live measurements and the breaker's trip response change, without needing real equipment. This is meant for building intuition about protection behavior and diagnosing symptoms, not for selecting or validating real overcurrent protection.