Protective Device Time-Current Calculator

Estimate trip time for inverse-time overcurrent devices at a given fault current level.

Overcurrent device rated current.
A
Available fault current at the device.
A
1=Standard Inverse, 2=Very Inverse, 3=Extremely Inverse.
Time dial/multiplier setting.

Results

Current Multiple-×
Estimated Trip Time-s
References: IEEE C37.112; IEC 60255-151; GE/SEL/ABB Relay Manuals