Circuit Breaker Size Calculator vs Short Circuit Current Calculator
Two calculators for the same neighbourhood of questions. Here is what each measures, what you feed in, and where you'd reach for one over the other.
Circuit Breaker Size Calculator
Determine the correctly sized circuit breaker for any electrical load, accounting for continuous versus non-continuous use, ambient temperature, and safety margins. Use it before wiring a new circuit or replacing a breaker.
- Answers
- Minimum Breaker Size (amps)
- Inputs
- Total Circuit Load, Load Type, Ambient Temperature, Safety Factor
Short Circuit Current Calculator
Compute the available short-circuit current (ASCC) at a fault point downstream of a transformer, accounting for transformer impedance and cable impedance to the fault location. Use this to verify that breakers and fuses have a sufficient interrupting rating.
- Answers
- Short Circuit Current (A)
- Inputs
- Transformer Size, Transformer Impedance, System Voltage, Cable Length to Fault, Cable Size (AWG/kcmil)
At a glance
| Circuit Breaker Size Calculator | Short Circuit Current Calculator | |
|---|---|---|
| Category | Electrical Home | Electrical |
| Answers | Minimum Breaker Size | Short Circuit Current |
| Inputs | 4 | 5 |
| Result unit | amps | A |
When to use each
Determine the correctly sized circuit breaker for any electrical load, accounting for continuous versus non-continuous use, ambient temperature, and safety margins. Use it before wiring a new circuit or replacing a breaker.
Compute the available short-circuit current (ASCC) at a fault point downstream of a transformer, accounting for transformer impedance and cable impedance to the fault location. Use this to verify that breakers and fuses have a sufficient interrupting rating.