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88 Cards in this Set
- Front
- Back
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What is electrical ground made to do?
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Protect people.
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Abbreviations
AC |
ALTERNATING CURRENT
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Abbreviations
C |
CONTACTOR
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Abbreviations
CA |
COOLING ANTICIPATOR
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Abbreviations
CC |
COOLING COMPENSATOR/ CONTACTOR COIL
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Abbreviations
CCH |
CRANKCASE HEATER
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Abbreviations
CFM |
CONDENSER FAN MOTOR
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Abbreviations
COMP |
COMPRESSOR
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Abbreviations
COV |
CHANGEOVER VALVE( 4 WAY VALVE)
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Abbreviations
CR |
CONTROL RELAY
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Abbreviations
CS |
CAPACITOR START/ CENTRIUGAL SWITCH
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Abbreviations
CSR |
CAPACITOR START-CAPACITOR RUN/ CURRENT START RELAY
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Abbreviations
DC |
DIRECT CURRENT
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Abbreviations
EFM |
EVAPORATOR FAN MOTOR
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Abbreviations
EFR |
EVAPORATOR FAN RELAY
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Abbreviations
F1,F2,F3 |
LINE 1 FUSE,LINE 2 FUSE,LINE 3 FUSE
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Abbreviations
FLA |
FULL LOAD AMPS
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Abbreviations
HA |
HEATING ANTICIPATOR
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Abbreviations
HP |
HIGH PRESSURE SWITCH
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Abbreviations
IFM |
INDOOR FAN MOTOR
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Abbreviations
IFR |
INDOOR FAN RELAY
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Abbreviations
LP |
LOW PRESSURE SWITCH
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Abbreviations
LRA |
LOCKED ROTOR AMPS
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Abbreviations
OFM |
OUTDOOR FAN MOTOR
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Abbreviations
OL |
OVERLOAD
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Abbreviations
PSC |
PERMANENT START CAPACITOR
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Abbreviations
PSR |
POTENTIAL START RELAY
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Abbreviations
PTC |
POSITIVE TEMPERATURE COEFFICIENT THERMISTOR
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Abbreviations
RA |
RUNNING AMPS
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Abbreviations
RC |
RUN CAPACITOR
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Abbreviations
RVR |
REVERSING VALVE RELAY
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Abbreviations
RVS |
REVERSING VALVE SOLENOID
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Abbreviations
SA |
STARTING AMPS
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Abbreviations
SC |
START CAPACITOR
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Abbreviations
S.E.P |
SERVICE ENTRANCE PANEL
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Abbreviations
SF |
SERVICE FACTOR
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Abbreviations
SP |
SHADED POLE
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Abbreviations
TB |
THERMAL BLOCK
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Abbreviations
TC |
COOLING THERMOSTAT
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Abbreviations
TH |
HEATING THERMOSTAT
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Abbreviations
VAC |
VOLTS,ALTERNATING CURRENT
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Abbreviations
XFMR |
TRANSFORMER
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Voltage is
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The pushing force that causes electrons to flow
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other names for Voltage
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potental,electrical pressure,electro motor force(EMP)
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Voltage is measurement
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volts
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Voltage algebraic symbol
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E
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Current is
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the controled movement of electrons through a conductor
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other names for current
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flowing electrons, intensity
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Units of measurement for current
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amprere(amp)
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Algebraic symbol for current
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I
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Resistance is
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opposition to current flow
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Other names for resistance
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load,curent consuming device, impedance
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Resistance of measurement
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OHM
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Algerbraic symbol for resistance
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R
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Three parts of a electrical circuit
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power source,conductor(path),load, and opt. switch
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A circuit gets it's name from what
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The load that the circuit runs
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What is a switch
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a device used to open or close a circuit
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How many dirctions does DC flow
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one
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What is DC used for in the industry
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Auto AC,electrical air cleaners,gas fernace controls ie pilot generators,solid state boards
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unwanted voltage drops are caused by
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dirty or burned contacts, loose conections,frayed wires
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what is the biggest cause of blown fuses?
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shorts
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What are some useful forms of energy
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heat,light,sound,magnetism
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what is the most usfull form of energy in HVAC industry
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Magnetism
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What is magnetism used for
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open and close valves,open and close switches,turn motors,operate transformers
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one watt of electrical power generates
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3.413 BTU/hour of heat
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How many watts = one horsepower
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746
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A graphic plot of the cycle of changing voltage is called
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sine wave
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a transformer works on the principal of
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induction
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Transformer
where voltage is applied,consumed energy to produce magnetism,it is a load |
primary side
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Transformer
where voltage is induced,is not a load,source of power to ciruit. |
secondary side
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two types of transformers
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step up,step down
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most important reasons for using a step down trams former
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safety efficiency
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important facts about series circuits
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curent is the same throughout the circuit,volt divides acording to the resistance of the load,switches are allway in series with the load they control,if one load opens the entire circuit opens.
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important facts about parallel
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voltage same the same throughout the cicuit,current divides,if one load opens it has no effect to the other loads in the circuit.
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two types of transformer configerations
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single phase, and polyphase
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pattern of polyphase transformers are
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delta and wye
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pattern of polyphase transformers that has a wild leg
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delta
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4 types of configerations for power sources
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240/120vac 60 cycle single phase,240/120vac 60 cycle three phase,208/120vac 60 cycle three phase,480/277 vac 60 cycle three phase
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power to your building may fluctuate up or down by how much
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10%
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all hot legs must be
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fused
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Neutral is never
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fused
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fuses are used to protect what
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wires
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how are switches shown in a schematic
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in the normal operating postion when the coil is de-engergized.
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relay coils are not wired in the the circuit with the load the controll except in what type of circuit
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holding
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what is a contactor
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a over grown relay
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contactors are rated over
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20 amps
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what is a starter
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contactor with built in overloads
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How are mechanical switches operated
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by outside forces like temp change,pressure change,air movement, a flowing fluid,and timer motors.
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