COMPONENTS / PARAMETER SIZING

Circuit Breaker Selection

Screen reference ratings by load type, starting method and operating current.

Input Parameters

Edit the example values. Results update as you type.

Supply Phases

Rated Voltage U

Enter circuit voltage for single phase and line voltage for three phase.

Load Type

Known Parameters

Operating Current I

Cable Ampacity Iᴢ (optional)

Enter ampacity after derating for actual conditions.

Cable ampacity has not been entered. Verify Iₙ ≤ Iᴢ and conventional operating-current conditions for the listed ratings.

Iscreen = Iᴮ × k · Iᴮ ≤ Iₙ ≤ Iᴢ

Iscreen = 30 × 1.2 = 36 A

Uses the entered load operating current.
Apply a preliminary margin for the load type, then screen common ratings against current and known ampacity limits.
Verify voltage rating, prospective short-circuit current, breaking capacity, trip curve and protection coordination.

Check closing inrush, time-current curves and upstream/downstream selectivity.

Parameter-matched candidates

Schneider · Acti9 iC60NOfficial source

3P · Curve C · 40 A · Icn 6 kA (IEC 60898-1); verify breaking capacity at the actual voltage

Rated margin above screening requirement: 0%

Lifecycle status varies by region. Sales have ended in some regions. Verify local product status before purchasing.

Verified 2026-11-05

Iᴮ ≤ Iₙ ≤ Iᴢ · I_screen = Iᴮ × k

Can load current determine breaking capacity?

Check prospective fault current at the installation point and verify coordination and trip conditions against manufacturer requirements.