Device Numbers Flashcards
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TIME-DELAY STARTING OR CLOSING RELAY - one which gives a desired amount of time delay between operations in an automatic sequence
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MASTER ELEMENT - initiating device to place an equipment in or out of operation
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Reserved for future applications
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MASTER CONTACTOR OR RELAY - device, generally controlled by device no. 1 to place an equipment into operation under the desired conditions and to take it out of operation under other or abnormal conditions
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STOPPING DEVICE - one whose primary function is to place and hold an equipment out of operation
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STARTING CIRCUIT BREAKER, CONTACTOR OR SWITCH - device whose principle function is to connect a machine to its source of starting voltage
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ANODE CIRCUIT BREAKER - used in the anode circuits of a power rectifier, primarily to interrupt the rectifier circuits on arc back
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CONTROL POWER SWITCH - manually operated switch or circuit breaker used for the express purpose of connecting and disconnecting the source of control power to and from the control bus or equipment
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REVERSING DEVICE - used to reverse the shunt-field connections of a synchronous converter during the starting sequence or for other special reversing functions
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UNIT SEQUENCE SWITCH - used to change the sequence of placing units in and out of service in multiple-unit equipments
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CONTROL POWER TRANSFORMER - serves as the source of a-c control power for operating a-c devices
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OVERSPEED DEVICE - is a direct connected speed switch which functions on machine overspeed
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SYNCHRONOUS-SPEED DEVICE - is one which operates at approximately normal synchronous speed of a machine
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UNDERSPEED DEVICE - functions on machine speed below a desired value
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SPEED REGULATING DEVICE - functions to hold the speed or frequency of a machine or system at a certain value or between certain limits
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BATTERY-CHARGING CONTROL DEVICE - is the battery charger
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SERIES FIELD SHUNTING CIRCUIT BREAKER OR CONTACTOR - serves to open and close a shunt circuit around a machine series field
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ACCELERATING OR DECELERATING CIRCUIT BREAKER, CONTACTOR, OR RELAY - one which is used to close or cause the closing of circuits for bringing a machine up to speed or shutting it down
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STARTING TO RUNNING TRANSITION CONTRACTOR OR RELAY - operates to cause the transfer of a machine from the starting to the running power connections
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ELECTRICALLY OPERATED VALVE - solenoid or motor operated valve
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IMPEDANCE RELAY - functions when the circuit impedance increases or decreases to a predetermined value
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EQUALIZER CIRCUIT BREAKER OR CONTACTOR - serves to make and break the equalizer or current-balancing connections for machine field, or voltage regulators
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TEMPERATURE REGULATING DEVICE - functions to hold the temperature of a machine or other apparatus between certain limits
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BUS TIE CIRCUIT BREAKER, CONTACTOR, OR SWITCH - serves to connect buses or bus sections together
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SYNCHRONIZING OR PARALLEL DEVICE - operates when two a-c circuits are within the desire limits of voltage, frequency, and/or phase angle, to permit the paralleling of these two circuits
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APPARATUS THERMAL DEVICE - one which functions at desired operating-temperature values or limits
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A-C UNDERVOLTAGE RELAY - functions on a given value of single-phase a-c under-voltage
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RESISTOR THERMAL DEVICE - functions upon excessive load indicating, limiting, or shifting resistor temperature
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ISOLATING CIRCUIT BREAKER, CONTACTOR, OR SWTICH - is used for the purpose of disconnecting one circuit from another
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ANNUNCIATOR RELAY - is a nonautomatic reset device with visual indications upon the functioning of protective devices
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SEPARATE EXCITATION DEVICE - connects a circuit such as a synchronous converter shunt field to a source of separate excitation during the starting sequence, or for energizing the excitation and ignition circuits of a power rectifier
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D-C REVERSE POWER RELAY OR DEVICE - one which functions on a given value of d-c reverse power
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POSITION SWITCH - one which makes or breaks contact when the main device or piece of apparatus, which has no device-function number, reaches a given position
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MOTOR-OPERATED SEQUENCE SWITCH - one which fixes the operating sequence of the major devices during starting and stopping, or during other sequential-switching operations
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BRUSH-OPERATING OR SLIP-RING SHORT-CIRCUITING DEVICE - one for raising, lowering, or shifting the brushes of a machine, or for short-circuiting the slip rings.
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POLARITY DEVICE - one which operates or permits the operation of another device on a given polarity only
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UNDERCURRENT OR UNDERPOWER RELAY - one which functions on a given minimum of current or power flow
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BEARING THERMAL DEVICE - one which functions on excessive bearing temperatures
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FIELD REDUCING CONTACTOR - one which inserts resistance in the field circuit of a machine or otherwise reduces its field excitation