Electrical Flashcards
Main panel box amp sizes?
100, 150, and 200 amps
What are the four main types of electrical injuries?
Electrocution, electric shock, burns, falls
Problems arise in equipment when there is a breakdown of insulation due to what?
Wear and tear, defective construction, misuse of equipment
What are the two types of electricity?
AC, DC
How do you make AC?
How do you make DC?
AC: Gererators
DC: Batteries, static, and lightning
At what frequency is AC in the US?
At what frequency is AC outside US?
60hz, 50hz
Ohms law defines the relationship between?
(P) power
(E) voltage
(I) current
(R) resistance
What is 1 ohm?
The resistance value in which 1 volt will maintain current of 1 amp
Resistance determines what?
How is it measured?
How much current will flow through a component.
In Ohms
Resistors are used for what?
Control voltage and current levels
What is power?
The amount of current x voltage at a given point measured in watts/ wattage
What is current?
How does it flow?
How is it measured?
Is what flows in a wire or conductor
Flows from neg to pos
Measured in amps
What is voltage?
How is it measured?
Difference in electrical potential between 2 points in a circuit.
Measured in volts.
How many watts is 1 hp?
1hp is equal to how much ft lb / min?
750 watts
33,000 ft lb/ min
What is the west virginia formula?
Watts= volts x amps
(W)=(v)(a)
v=w/a
a=w/v
Ground guage (copper) service sizes.
8-100a
6-125a
4-165a
3-200a
4 important “musts” for grounding rod
1/2” diameter
Must be no less than 8’ in length
Must be in ground at least 8’
Installed below permanent moisture level
What is bonding?
Permanent joining of metallic parts to form an electrically conductive path.
Why bond?
Establish effective path for fault current
To facilitate the operation of the over current device.
What are the wire gauge sizes?
How many amps are each rated for?
14ga-15amps 12ga-20amps 10ga-30amps 8ga-40amps 6ga-50amps
How to determine amps required?
Watts / volts (110 or 240) round up
What must you know when installing branch circuits?
# of loads on circuit Watts on each load Amps required by each load Voltage required by the load Distance from service panel to load
