Breakers, fuses, fault current, grounding, and arc flash
Circuit Breaker Size Calculator
Estimate a standard MCB or MCCB current rating from load power, voltage, phase, power factor, and sizing factor.
Open calculatorCALCULATOR CATEGORY
Circuit Protection & Grounding
Breakers, fuses, fault current, grounding, and arc flash
Breakers, fuses, fault current, grounding, and arc flash
Short Circuit Current Calculator
Estimate available transformer secondary fault current from transformer kVA, impedance, voltage, phase, and optional utility fault contribution.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Fuse Sizing & Selection Calculator
Size a preliminary gG, aM, or gPV fuse and check load current, cable ampacity, breaking capacity, motor starting duty, or PV module limits.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
MCB Inrush Compatibility Checker
Compare equipment inrush current with IEC-style B, C, or D magnetic-trip bands and check whether available fault current supports instantaneous operation.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
RCD & RCBO Selection Calculator
Select a starting residual-current type, sensitivity, poles, rated current, overcurrent curve, and breaking capacity for common loads.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Grounding Resistance Calculator
Estimate single vertical ground-rod resistance and a preliminary multiple-rod result from soil resistivity, rod length, diameter, count, and spacing.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Circuit Breaker Selectivity and Cascading Checker
Screen upstream and downstream breaker rating, curve, breaking capacity, and fault-current coordination.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Earth Fault Loop Impedance Calculator (Zs)
Calculate actual earth fault loop impedance and compare it with a device-based maximum Zs input.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Arc Flash Incident Energy Calculator – IEEE 1584-2018
Calculate IEEE 1584-2018 arcing current, incident energy, and arc-flash boundary for normal and reduced-current clearing-time scenarios.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
AFDD Requirement & Selection Calculator
Screen an AFDD or AFDD-RCBO requirement and check a preliminary LSP configuration by circuit, current, curve, residual sensitivity, and fault level.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
DC Circuit Breaker Sizing Calculator
Calculate DC design current and screen a DC MCB or MCCB for current, voltage, cable ampacity, poles, and breaking capacity.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
ACB Frame & LSIG Setting Calculator
Build a preliminary ACB frame and LSIG worksheet from design current, cable capacity, fault level, downstream rating, and entered pickup multiples.
Open calculatorBreakers, fuses, fault current, grounding, and arc flash
Circuit Breaker Accessory Power Calculator
Calculate peak and continuous control-supply demand for shunt trips, undervoltage releases, motor operators, and other breaker accessories.
Open calculator