Ship Electrical Short Circuit Current, Breaker Capacity & Busbar Fault Level Tool
Screen shipboard AC fault levels against circuit-breaker interrupting and making capacity instead of comparing generator kVA with breaker kA. Simple mode estimates main-bus symmetrical and peak short-circuit duty. Advanced combines generator, transformer/shore and motor contributions through entered fault-path impedance, then checks multiple fault locations, breaker margins, busbar thermal duty and N-1 source configurations.
Source & Motor Contribution
Breaker Ratings
System Basis
AC Source Register
Generator / transformer rows use rating and entered impedance. “Direct kA” rows use an OEM or study-derived initial symmetrical contribution. Quantity is treated as identical units operating in parallel.
| Use | Online? | Type | Name | Qty | Rating kVA | Z / Xdʺ % | Direct Ikʺ kA / unit | X/R |
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Running Motor Contribution Register
Motor short-circuit contribution is screened as entered multiple × calculated full-load current. For a formal marine study, use the motor contribution model required by the applicable standard/class method.
| Use | Running? | Name | Qty | Rated kW | PF | Efficiency | Fault × FLA | X/R |
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Fault Location / Breaker Duty Register
Path R and X are the common impedance from the analyzed source bus to the fault location. Breaker RMS breaking capacity, peak making capacity and busbar short-time withstand are compared with the calculated prospective duty.
| Use | Fault location | Path R mΩ | Path X mΩ | Breaker break kA RMS | Breaker make kA peak | Bus Icw kA | Icw duration s | Clearing time s |
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