UL 2111:2016 pdf free download – STANDARD FOR SAFETY Overheating Protection for Motors.
3.3 FIELD-WIRING TERMINAL — A terminal to which connection is capable to be made in the field.
3.4 IMPEDANCE-PROTECTED MOTOR — A motor that relies solely upon the impedance of the windings alone to prevent overheating.
3.4.1 INSULATION SYSTEM — An assembly of insulating materials used to isolate the live parts from ground and from parts of opposite polarity. All materials in contact with the windings are considered part of the system.
3.4.2 INTERMITTENT DUTY MOTOR — A motor intended to be connected to a load other than a fan or blower and that is intended to operate for a specified time period.
3.4.3 Deleted
3.4.4 LOCKED-ROTOR CURRENT — The current measured from the line when the armature or rotor is prevented from rotating.
3.4.5 LOW-VOLTAGE CIRCUIT — A circuit involving a peak open-circuit potential of not more than 42.4 volts. It is supplied by a battery, by a Class 2 transformer, or by a combination of a transformer and a fixed impedance that as a unit, complies with all performance requirements for a Class 2 transformer. A circuit derived from a line-voltage circuit by connecting a resistance in series with the supply circuit as a means of limiting the voltage and current is not considered to be a low-voltage circuit.
3.4.6 LOW-VOLTAGE LIMITED ENERGY CIRCUIT (LVLE) — A low voltage or limiting impedance circuit.
3.5 MANUALLY RESET PROTECTOR — A device that incorporates a bimetal that is calibrated to open the motor circuit upon reaching a certain temperature and requires manual resetting to reclose the motor circuit.
3.5.1 MOTOR STARTER — A device that is intended to start a three-phase motor and contains a method of protection to prevent overheating of a motor. A relay or contactor is not considered to be a motor starter.
3.5.2 MULTI-SPEED MOTOR — A motor that operates at one or more speeds.
3.6 OPEN MOTOR — A motor having ventilating openings that provide for the passage of external cooling air over and around the windings.
3.6.1 PERMANENT-SPLIT CAPACITOR MOTOR — A motor with the same value of capacitance for both starting and running conditions. The motor has no start switch.
3.6.2 POLYPHASE PROTECTOR — A protective device that opens the circuit for each phase of the motor when the protector operates.
3.6.3 PRIMARY PROTECTOR — A protector that is expected to operate during the abnormal testing of a motor sample.
3.7 SECONDARY (BACK-UP) PROTECTION — A protector that does not operate under normal running or locked rotor test conditions, without further stress applied to the motor by increased winding temperature, ambient temperature, or voltage.
3.7.1 SHADED-POLE MOTOR — A single-phase motor with a main winding and one or more short-circuited windings (shaded coils). The motor has no capacitor nor start switch.
3.8 SINGLE-OPERATION DEVICE — A device that incorporates a bimetal that is calibrated to open the motor circuit upon reaching a certain temperature and is resettable only by cooling to minus 35°C (minus 31°F), or lower.
3.8.1 SOLID-STATE PROTECTION — Electronic circuitry integral to or provided with a motor to monitor winding temperature and/or current to prevent overheating. The protection is typically designed to reset automatically after motor temperatures return to normal condition, but circuitry requiring manual reset does exist.
3.8.2 SPLIT-PHASE MOTOR — A single-phase motor having a main winding and an auxiliary winding, which is designed to operate with no external impedance in either winding. The auxiliary winding is energized only during the starting operation and is open-circuited during the running operation. The motor has no capacitor, but does have a start switch.
3.9 THERMAL CUTOFF — A device that incorporates a melting alloy or other material that is calibrated to permanently open the motor circuit upon reaching a certain temperature.
3.10 THERMAL-DEVICE-PROTECTED MOTOR — A motor that relies upon a device (protector) to prevent overheating.