Under 2023 NEC 430.6(A), an ordinary single-speed, continuous-duty 1800-RPM motor is covered by the Article 430 current tables. It is not a high-torque motor, canned pump or listed motor-operated appliance, and no nameplate-value exception applies. Which current basis is used for conductor ampacity and branch-circuit short-circuit and ground-fault protection?
- AA measured running current alone
- The applicable Article 430 table full-load current
- CThe nameplate locked-rotor current
- DThe nameplate full-load current instead of the table value
Where to look it up
https://captaincode2023.leviton.com/node/346
Why B is correct
For this stated general application, use the applicable table current. Nameplate current is used for separate overload protection, but that is not its only possible use: 430.6 also specifies nameplate treatment for particular motors and exceptions. A measured operating current is not the table basis. This question selects the current source; sizing factors and other installation conditions must still be applied separately. Source: https://captaincode2023.leviton.com/node/346