This guide know the NEC or CEC code requirements for motor conductors for different applications.
Motor conductors are the conductors that carry electricity to motors. Protecting them is important because if too much current flows, the conductors can overheat and cause damage or fire. Overload protection devices monitor the current. If the motor draws too much electricity, these devices cut off the power to keep the motor and conductors safe. The CEC and NEC have code requirements to ensure that the conductors are sized properly for the motor and its application.
Continuous — any application of a motor where the motor can operate continuously with load under any normal or abnormal condition of use.
Non-Continuous: an application of a motor where the apparatus driven by the motor has characteristics or ratings described as Short-time duty, Intermittent duty, Periodic duty, and Varying duty.
Short-time duty: a requirement of service that demands operation at a substantially constant load for a short and definitely specified time (Operating valves, raising or lowering rolls, etc.
Periodic duty: a type of intermittent duty in which the load conditions are regularly recurrent (Rolls, ore- and coal-handling machines, etc.).
Intermittent duty: a requirement of service that demands operation for definitely specified alternate intervals of a) load and no-load; b) load and rest; or c) load, no-load, and rest. E.g. Freight and passenger elevators, tool heads, pumps, drawbridges, turntables, etc.
Varying duty: a requirement of service that demands operation at loads and for intervals of time, both of which may be subject to wide variation.
X-minute rating: This is the maximum time (X) a motor can operate continuously before overheating. It is typically found on the motor nameplate.
For educational purposes only, please consult an electrician or electrical engineer for professional advice.