Rapid Shutdown Calculator

Determine NEC 690.12 rapid shutdown compliance requirements for your solar installation.

Check with your AHJ for adopted code year
Maximum string voltage
From array boundary to main service panel

NEC 690.12 Requirements Summary

NEC Year Requirement Voltage Limit
2014Conductors >10ft from array30V in 10 sec
2017Within array boundary80V in 30 sec
2020Module-level (1ft boundary)80V in 30 sec
2023Enhanced module-level80V in 30 sec

Rapid Shutdown Formula

String Voltage = Panels x Voc x 1.14 (cold factor)
RSD Required if: Voltage > 80V within boundary
Compliant: <80V within 30 sec, <30V in 10 sec outside