This simulator magnifies a single-pole interruption chamber to show what actually happens between the moment contacts separate and the moment current is truly interrupted. Open the contacts under an AC or DC supply and watch the arc, current, gap voltage and dielectric recovery play out — in slow motion down to 1000x — as the mechanism keeps opening and the recovering gap competes against imposed voltage stress.
• A real-time 3D magnified single-pole chamber — copper conductors, silver contacts, a teal moving arm, violet splitter plates and a luminous magenta arc — with toggleable chamber walls, auto-rotate and expand. • An Open contacts control with Run slow motion, Advance 0.1 ms, Advance 1 ms and Advance 20 ms stepping, at playback speeds of 1000x, 100x or 10x slow motion. • A Supply selector for AC (voltage is RMS) or DC (voltage is constant), plus source isolation, with settings staged until you press Apply to start a fresh trial. • A Waveforms & recovery tab with four charts: current through the contacts, voltage across the contact gap, a recovery-competition chart (modeled dielectric withstand vs. absolute imposed recovery voltage), and contact travel over time. • The underlying model equations for the arc-voltage law and imposed recovery-voltage fixture. • A "Compare arc-chute assistance" tool that runs paired 80 ms trials — one with zero splitter plates and one with your selected plate count — without disturbing the live trial. • A Test & diagnose tab (labeled Experiments) with a Model verification bench that runs 18 automated checks, plus a timestamped event log with trial JSON export. • A Learn & assess tab with guided lessons, a knowledge-check quiz and a written scope/references statement.
When contacts separate under load, the current doesn't stop — an arc bridges the widening gap and keeps conducting. In this model the arc is a series RL circuit with an opposing arc-voltage law, so the arc voltage subtracts from the source voltage while current keeps flowing. Under AC supply, the current naturally crosses zero twice per cycle; the arc can only be truly extinguished at one of those current-zero crossings, which is why timing relative to the AC waveform matters so much (the DC case has no natural current zero, so a DC arc must be actively driven toward zero by other means).
At current zero, the interruption isn't finished — the gap now has to rebuild its dielectric strength (withstand) fast enough to outrun the recovery voltage the source imposes on it. If the imposed stress crosses above the recovering withstand curve, a restrike can occur, meaning the source can resupply the arc voltage and sustain conduction. This is exactly the race the Recovery competition chart shows. Splitter plates in the arc chute help by lengthening and cooling the arc, which is what the paired plate-comparison trials are designed to demonstrate.
The current chart shows the integrated series RL current — note how the arc voltage opposing it can alter the waveform, especially as the arc voltage becomes significant relative to the source. The gap-voltage chart is signed while the arc still conducts, then switches to imposed recovery stress magnitude once the current reaches zero. The recovery chart directly overlays the cyan modeled dielectric withstand curve against the magenta absolute imposed recovery voltage — where they cross is a restrike risk. The gap chart tracks contact travel; full mechanical travel doesn't, by itself, prove successful interruption if the arc keeps restriking.
This is a phenomenological teaching model: it integrates a simplified RL/arc-voltage circuit and a separate stress-versus-withstand comparison rather than solving actual plasma physics, arc motion, magnetic blowout, gas chemistry, recovery capacitance or switching overvoltage. It does not compute arc-flash hazard energy, and AC/DC trials are separate conceptual exercises, not an endorsement of using an AC-rated breaker on DC.
Separating the contacts creates a gap, but the arc that forms across it keeps conducting current. In this AC model, the arc can only extinguish at a natural current zero — the instant the sinusoidal current crosses zero. The simulator lets you open the contacts and watch the arc persist until that current-zero moment.
After current zero, the gap must rebuild dielectric strength (withstand voltage) faster than the imposed recovery voltage stresses it, or the gap will restrike into a sustained arc. The chart plots the modeled dielectric withstand curve against the absolute imposed recovery voltage so you can see which one is winning the race.
The "Run paired 80 ms tests" comparison runs two separate trials with your staged settings — one with zero splitter plates and one with your selected plate count — so you can see how splitter plates change arc behavior without altering your live trial.
This is a phenomenological air-arc laboratory that integrates a series RL circuit with an opposing arc-voltage law and a separate recovery-stress/withstand comparison. It does not resolve plasma physics, arc motion, magnetic blowout, gas chemistry, actual material properties, recovery capacitance, switching overvoltage, certified interrupting duty, or arc-flash hazard energy.