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Commonly used terms in the Electrical industry.
no voltage holding coil
a holding coil that keeps the main-line contactor closed on zero voltage conditions. DC motor controllers that contain this feature are used in places where the motor is vital to the operation of a process. These controllers can maintain control to the motor under momentary line power loses, by using the CEMF of the coasting armature to keep power to the main-line coil/contactor. If power to the motor controller is not restored within a short period of time, the motor coasts to a speed where it can no longer keep the main-line contactor closed. At this point, the m-coil drops out to insure starting resistors are placed back in the circuit.
nominal voltage
a number given to a system to name its classification of voltage, such as rated values.
outage
(1) the percentage of time or area for which a communication system does not provide acceptable quality.
(2) loss of power from all or part of a power system.
outage inferencing
the act of identifying the probable location of an outage based on information received from customer trouble calls and power monitoring units.
overvoltage
a voltage having a value larger than the nominal voltage for a duration greater than 1 minute.
overvoltage relay
a protective relay that operates on overvoltage.
pickup voltage
See
pickup current
primary voltage
in power distribution the voltage at the primary winding of the distribution transformer.
rated voltage
the voltage at which a power line or electrical equipment is designed to operate.
reduced-voltage motor starter
a device designed to safely connect an electric motor to the power source while limiting the magnitude of its starting current. Various electromechanical configurations may be used: primary resistor, delta-wye, part-winding (requires special motor or dual voltage windings). Power electronic devices may also be utilized to gradually increase the applied voltage to system levels. The complete starter must also include fault and overload protection.
sealing voltage
the voltage necessary to complete the movement of the armature of a magnetic circuit closing device from the position at which the contacts first touch each other.
secondary voltage
in power distribution work the voltage at the secondary of the distribution transformer.
secondary voltage control
an automatic voltage control scheme that is similar in function to the automatic voltage regulator, but its purpose is to control a bus voltage which need not have a synchronous generator connected at the bus.
step voltage
in power system safety studies, the voltage measured across two points on the ground which are separated by a distance equal to an average person's step while walking over the area in question.
surge response voltage
the voltage that appears at the output terminals of surge protection equipment and is seen by loads connected to that device both during and after a surge condition.
tag
(1) that part of a memory address held in a direct mapped or set associative cache next to the corresponding line, generally the most significant bits of the address.
(2) a field attached to an object to denote the type of information stored in the object. The tag can flag control objects to prevent misuse. Tags can be used to identify the type of each object and thereby to simplify the instruction set, since, for example, only one ADD instruction would be necessary if each numeric object were tagged with its type (integer vs. real, for example).
(3) a temporary sign which is affixed to a network device to identify particular instructions. An example of this might be placing a tag which indicates "Do Not Close" on a circuit breaker which has been opened to permit downstream work.
undervoltage
a voltage that is less than nominal for a time greater than 1 minute.
undervoltage relay
a protective relay that operates on low voltage or loss of voltage.
utilization voltage
the voltage across the power input terminals of a piece of electrical equipment.
voltage collapse
the rapid and uncontrollable drop of bus voltage due to a slight increase in load at the bus, generally characterized by inadequate reactive support in a high-load area.