N.E.C. Temperature Code (T Code): A National Electrical Code index for describing maximum allowable skin (surface) temperature of a motor under any normal or abnormal operating conditions. The T codes are applicable to U.L. listed explosion-proof motors. The skin temperature shall not exceed the minimum ignition temperature of the substances to be found in the hazardous location. The T code designations apply to motors and other types of electrical equipment subject to hazardous location classification.

NA: The National Electrical Manufacturers Association is a nonprofit organization organized and supported by manufacturers of electric equipment and supplies. NA has set standards for horsepower ratings, speeds, frame sizes and dimensions, standard voltages and frequencies with allowable variations, service factors, torque, starting current & KVA and enclosures.

Nameplate: The plate on the outside of the motor describing the motor horsepower, voltage, speed efficiency, design, enclosure, etc.

Navy Service A: Motors designed to meet requirements of MIL M-17059 or MIL M-17060 for high shock and service and are essential to the combat effectiveness of a ship. These motors are usually made of nodular iron.

NEC: National Electric Code, a safety document produced by the NFPA.

NEMA - National Electrical Manufacturer's Association: Acronym for an organization which sets standards for motors and other industrial electrical equipment.

Neodymium Iron Boron: A type of rare-earth permanent magnet material.

Nodular Iron (Ductile Iron): Special cast iron with a crystalline formation, which makes it capable of handling high shock.

Noise: A test performed to verify the motor sound level, conducted in accordance with IEEE-85. The tests are performed under no-load conditions in sound room.

NTC - Negative Temperature Coefficient: A negative temperature coefficient thermistor is used to detect and protect a motor winding from exceeding its maximum temperature rating. Resistance of the device decreases with an increase in temperature.


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