Equipment & SystemsQuestion 254 of 521
In a motor installation, what is the primary function of the motor controller?
a.To provide short-circuit and ground-fault protection
b.To start and stop the motor by connecting and disconnecting it from the power source
c.To protect conductors from overload only
d.To serve as the required disconnecting means for maintenance
Explanation
NEC Article 430 Part VII defines the controller as the device that starts and stops the motor by making and breaking the motor-circuit current. Short-circuit protection, overload protection, and the disconnecting means are separate required elements, though one device can sometimes serve more than one role.
Law Reference: 2023 NEC §430.81Practice all 521 questions free — no signup required.
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