NEC
What does the abbreviation stand for?
National Electrical Code
What does AWG stand for?
American wire gauge
Calculate the resistance for a light that consumes 4.5A and operates on a voltage of 12V.
12/4.5=2.66 ohms
G.S.T
General sales tax
Define safety ?
the condition of being protected by any harm
What is the primary purpose of a surge protective device?
To protect electrical system by diverting excess voltage to the ground during strikes or switching operations.
What is UF-B?
Underground Feeder cable. Waterproof, can be directly buried, used for outdoor circuits, and outbuildings.
Calculate the load if their is 12,300w and 11,700.
100
Power
The rate at which electrical energy is transferred or consumed. Measured in Watts (W).
Identify two safety in a breaker panel
Main breaker, branch circuit and ground
How do you convert 206.6 kw to volt-amps (VA)?
1,000 x 206.6 = 206,600 VA
What wire size is needed if the amp calculations come to 80A? (This is for a service entrance.)
#2 AWG
What is the resistance of a circuit if it has 5000w and runs on 240v?
20.8A
11.5 answer
Branch Breaker/ Branch circuit
Individual circuit breakers that protect specific circuits throughout the building.
What is insulation?
is a material that does NOT conduct electricity
How many chapters does the NEC book have?
it has 9 (nine) chapterss
If there is an electric dryer consuming 5000 watts and a welding machine consuming 6000 watts, what size wire is recommended? (apply 125% overcurrent protection)
57A, therefore, a #6 AWG is needed.
If 4.6V is the voltage drop, how much is it in %?(supply volts is 120)
3.61%
Magnetic Trip
An electromagnet responds to sudden current surges. High current creates a magnetic field that trips the breaker instantly.
What is the purpose of grounding and bonding ?
Ensure that there is low impedence path for fault current
List any of the NEC book chapters?
Chapter 1: General
chapter 2:Wiring and protection
Chapter 3: wiring methods and materials
Chapter 4:Equipment and general use
Chapter 5:Special Occupanies
Chapter 6: Special Equipment
Chapter 7: Special Conditions
Chapter 8: Communications systems
Chapter 9: Table
List the amperage for the following wire gauges:
14AWG, 12AWG, 10AWG, 8AWG, 6AWG, 4AWG, 2AWG
15, 20,30,40,60,75,100
Calculate the imbalance if phase A has 12,300 and phase B has 11,700.
4.87%
Thermal Trip
A bimetallic strip heats up with current flow. Sustained overload causes the strip to bend and trigger the trip mechanism.
Which chapter in the NEC book talks about protection ?
Chapter 2