What can this calculator do?

Enter the DC network — nominal voltage, busbars, cable sections and lengths and the DC sources (battery bank, smoothing capacitor, rectifier or DC machine) — and choose the fault points. For each point the engine superposes the partial current of every DC source over the minimum-resistance cable path and returns the peak current ip, the quasi-steady current Ik, the ratio κ = ip/Ik, the loop time constant τ, the rise time 3τ, the time to peak and the DC short-circuit power, with a per-source contribution table, a time-current decay chart and a network sketch. Typical uses: rating DC switchgear and busbars, checking a battery-bank installation, and showing which source contributes most at a given fault point. Missing data is shown as missing, never as zero.

Which standard and which model are behind the numbers?

IEC 61660-1 in its simplified engineering form: the partial currents are superposed arithmetically, ip = Σ ip,s and Ik = Σ Ik,s, without the clause 3.1 correction factor; R and L are lumped and the cable loop is the minimum-resistance path found by Dijkstra, i.e. the worst case. No arc-voltage model, no power-electronic current limiting and no IEC 61660-2 mechanical or thermal effects are included, and the page states this.

Why is a per-source contribution table shown?

Because the total peak depends on which sources actually reach the fault point: the table gives each source's model, ip,s, Ik,s, κs, loop R and L and the path, so you can see that a fault away from the battery is fed mainly through the cable loop and that the superposed current really decays. A source that cannot reach the point contributes nothing and is reported as unavailable, not as zero.

DC short circuit — IEC 61660-1

Short-circuit current at the DC busbars of an auxiliary DC installation: the engine superposes the partial current of every DC source (battery bank, smoothing capacitor group, rectifier / DC machine given as an explicit current) over the minimum-resistance cable path, and reports the peak ip, the quasi-steady Ik, the ratio κ = ip/Ik, the loop time constant τ, the rise time and the DC short-circuit power for every selected fault point.

Step 1 of 3DC short circuit — IEC 61660-1

Pick a scheme first — then this column can calculate

This column runs the real engine on your project scheme, and there is none yet — that is why no calculation buttons are shown here (they are not broken). Start with any of the ways below; the fastest is the built-in example (one click, real parameters).

Two ways in — pick either one

The studies in this column normally run on a whole scheme. If you only need one calculator-type function, you do not have to build a scheme.

① Load a real example scheme (fastest)

10 kV incoming (200 MVA short-circuit level) → 1250 kVA transformer (Dyn11) → LV main switchboard → busbar → 5 feeders plus a fire/emergency ATS branch. 1000 kW calculated load, cosφ 0.85, power-factor target 0.95.

Load the real example scheme and start calculating →

Or pick a ready-made scheme in the scheme library →

The scheme and its parameters go straight into your browser; replace the data with your own at any time.

② Do not load a scheme — just type the numbers (calculator mode)

Calculator mode computes the few outputs that only depend on parameters you type in yourself. Anything that genuinely needs the whole system (full-network load flow, coupling with other devices) is shown as “needs a scheme” and no number is given.

Nothing is pre-filled and nothing is invented: leave a required field empty and the result area says “unavailable”.

③ Or build your own scheme

In the studio, place devices, wire them and pick models — that becomes your project scheme (drawings / BOM / report can be exported).

Open the studio →

Need a hand?

Use the chat bubble bottom-right, or Contact us — we will set the example to your site parameters.

Note: every number comes from the engine. With no scheme, nothing is invented here.

Frequently asked questions

What can this calculator do?: Enter the DC network — nominal voltage, busbars, cable sections and lengths and the DC sources (battery bank, smoothing capacitor, rectifier or DC machine) — and choose the fault points. For each point the engine superposes the partial current of every DC source over the minimum-resistance cable path and returns the peak current ip, the quasi-steady current Ik, the ratio κ = ip/Ik, the loop time constant τ, the rise time 3τ, the time to peak and the DC short-circuit power, with a per-source contribution table, a time-current decay chart and a network sketch. Typical uses: rating DC switchgear and busbars, checking a battery-bank installation, and showing which source contributes most at a given fault point. Missing data is shown as missing, never as zero.
Which standard and which model are behind the numbers?: IEC 61660-1 in its simplified engineering form: the partial currents are superposed arithmetically, ip = Σ ip,s and Ik = Σ Ik,s, without the clause 3.1 correction factor; R and L are lumped and the cable loop is the minimum-resistance path found by Dijkstra, i.e. the worst case. No arc-voltage model, no power-electronic current limiting and no IEC 61660-2 mechanical or thermal effects are included, and the page states this.
Why is a per-source contribution table shown?: Because the total peak depends on which sources actually reach the fault point: the table gives each source's model, ip,s, Ik,s, κs, loop R and L and the path, so you can see that a fault away from the battery is fed mainly through the cable loop and that the superposed current really decays. A source that cannot reach the point contributes nothing and is reported as unavailable, not as zero.