Electrical And Controls Flashcards
(20 cards)
What is represented by a thick solid line on a HVAC unit wiring diagram?
Factory high voltage wiring
What is the most useful for troubleshooting by a service technician?
The schematic diagram
What is a ATOM?
The smallest unit of matter that can exist and still retain its chemical properties
What three things make up an atom?
Electrons
Protons
Neutrons
What the difference between Electrons,Protons and neutrons?
Electrons: particles that are on the outside of an atom, they have a negative charge
Protons: particles inside atom nucleus, they have a positive charge
Neutrons: have no charge, located inside nucleus
What is a conductor?
Materials that have a large number of free electrons that can move more easily to another atom to create an electrical charge
What materials make good conductor and why?
Most metals are good conductors
Copper wire is especially popular due to its conductivity and low cost
What are some examples of insulators?
Ceramic and rubber, thermoplastic to coat wire
What is an insulator used for?
They are often used to cover conductors to keep the current from making contact with other conductors, equipment or people
What is voltage?
The force or pressure (electromotive force) that pushes electrons through an electric circuit
What does voltage measure? And how is it written in formulas and equations ?
Voltage measures electromotive force, and it is written as “E”
What is a COULOMB?
In formulas or equations how is it written?
A measurement of the quantity of electrical charge, written as “Q”
The rate of electrical current flow is measured in what?
AMPS
In formulas and equations how is Amps represented?
Since a amp is a measure of a currents intensity it is represented as “I”
The relationship between the amount of charge (coulombs or Q) the duration of a charge, and amps (I) can be expressed with what equation?
Q= I x t
If a current of 4amps flows through a conductor for 30 seconds, the total amount of electrical charge charge that flowed through the conductor could be calculated as what?
Q= 4 A x 30 seconds = 120 coulombs
What is the difference between a milliamp and micro amp ?
Milliamp= 1/1000th of an amp
Microamp = 1/1000000 of an amp
What is a WATT?
In formulas how is Represented?
A measure of the rate at which electrical work is done, which is dependent on both the voltage and current
Represented by P which stands for power
What are the two equations to represent watt?
Watts = volts x amps
P = E x I
Watts are a useful measure for smaller currents, but heating a building requires a larger measurement. If that’s the case in HVAC the energy use of equipment is measured in what?
Kilowatts(kW)
The prefix kilo means 1000, so 1kW is equal to 1000 W
