Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/88

Click to flip

88 Cards in this Set

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