Breaker coordination screening
The generic screen compares current ratings, B/C/D magnetic bands, and breaking capacity.
Rrating = In,up / In,downImagnetic = kcurve × InIcn ≥ Ikwhere:
- In
- Breaker rated current[A]
- kcurve
- Generic magnetic-trip multiple
- Icn
- Breaking capacity[kA]
- Ik
- Prospective fault current[kA]
Only a manufacturer selectivity or cascading table can confirm the exact paired devices.
How to use the Circuit Breaker Selectivity and Cascading Checker
Screen upstream and downstream breaker rating, curve, breaking capacity, and fault-current coordination. Start by choosing the operating mode, then enter values from nameplates, measurements, or project documents in the units shown. The result updates immediately and keeps intermediate quantities visible for review.
- Confirm the system and calculation mode.
- Enter measured or manufacturer-rated values.
- Review the primary result and intermediate metrics.
- Continue with the related protection or equipment-selection checks.
Calculation method and validation
The equations and symbol definitions above show the complete calculation basis. Inputs are checked before calculation so zero, negative, incompatible, or physically impossible combinations are flagged instead of silently producing a misleading result.
How to interpret the result
Use the main result as a starting value and read every supporting metric. Generic B/C/D magnetic bands only No manufacturer energy-selectivity or cascading table is embedded A passing or recommended result means the entered mathematical conditions are satisfied; it does not certify the complete installation or a particular product combination.
- Generic B/C/D magnetic bands only
- No manufacturer energy-selectivity or cascading table is embedded
Selection limits and next checks
Preliminary engineering estimate only. Verify the final design against the current applicable standard, local rules, manufacturer data, and project conditions. A positive screening result is not proof of selectivity or backup protection; use the exact paired-device manufacturer table. Compare the output with the current applicable standard, local rules, exact VIOX product datasheet, environmental conditions, protection coordination, and the engineer's project requirements before procurement or installation.
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Assumptions
- Generic B/C/D magnetic bands only
- No manufacturer energy-selectivity or cascading table is embedded
Important Warnings
- Preliminary engineering estimate only. Verify the final design against the current applicable standard, local rules, manufacturer data, and project conditions.
- A positive screening result is not proof of selectivity or backup protection; use the exact paired-device manufacturer table.