Motor Protection Calculator

Calculate motor branch circuit protection sizes: breaker, overload relay, and conductor sizing per NEC 430.

Full load amperes from NEC Table 430.250.
A
Motor service factor. 1.0 or 1.15 typical.
1=Inverse time breaker, 2=Instantaneous, 3=Fuses.
Motor voltage.
V

Results

Min Conductor Ampacity-A
Max Overload Protection-A
Max Branch Circuit Protection-A
Min Disconnect Rating-A
References: NEC Article 430 — Motor Circuits; NEMA ICS