Electrical Theory
In a DC circuit, if you have a resistance of 10 ohms and a voltage of 120V, this is the amount of current flowing through the circuit.
12 Amps (Calculated as 120/10)
According to Article 90.1, the purpose of the NEC is the practical safeguarding of these two things from hazards arising from the use of electricity.
Persons and Property
This is the common name for the oxide-inhibiting compound applied to aluminum conductors to prevent poor connections.
Anti-oxidant compound
This is the acronym for the OSHA-mandated practice of ensuring equipment is de-energized and cannot be restarted while being serviced.
Lockout/Tagout (LOTO)
In a standard Start/Stop station, the "Stop" button is electrically connected in this configuration (Series or Parallel).
Series
This property of a circuit opposes a change in current flow and is measured in Henrys.
Inductance (measured in Henrys)
Article 100 defines this type of person as one who has skills and knowledge related to the construction and operation of electrical equipment and has received safety training.
Qualified Person
When stripping insulation, you should avoid "ringing" the wire, which creates this physical defect that can lead to a break under stress.
Ringing
This boundary is the distance from an exposed energized conductor where a person could receive a second-degree burn if an arc flash occurred.
Arc Flash Boundary
This component protects the motor from overheating by breaking the circuit when it senses a prolonged overcurrent condition.
Overload Relay
In this type of circuit, the total resistance (Rt) is always less than the smallest individual resistor in the circuit.
Parallel Circuit
This Chapter 2 Article covers the requirements for "Branch-Circuit, Feeder, and Service Load Calculations."
Article 220
According to Article 110.14(D), this type of tool must be used to ensure terminations are tightened to a specific numerical value if identified on the equipment.
Torque wrench
When using a multi-meter to test for the absence of voltage, you should follow this three-step "Live-Dead-Live" process. What are the three steps?
Test known live source, 2. Test target circuit, 3. Re-test known live source.
To reverse the direction of a three-phase AC motor, you must swap any two of these.
Swap any two phases
This term describes the "push" or electrical pressure in a circuit, also known as Electromotive Force (EMF).
Voltage (or Electromotive Force / EMF)
Per Article 310, this is the standard unit of measurement used for large conductor cross-sectional areas (above 4/0 AWG).
kcmil
This is the maximum number of 12 AWG THHN conductors allowed in a 1/2" EMT conduit
9
An Arc Fault Circuit Interrupter (AFCI) is designed to detect a persistent arcing condition, whereas this device is designed to protect people from line-to-ground shock.
GFCI
In a ladder diagram, this type of contact remains open until the coil is energized.
Normally Open (N.O.)
Calculate the total capacitance (Ct) of two 100μF capacitors connected in series.
50μF
Table 310.16 is used to determine this—the maximum current, in amperes, that a conductor can carry continuously under the conditions of use.
Ampacity
This specific type of "long-barrel" or "short-barrel" connector requires a mechanical or hydraulic tool to permanently deform the metal around a conductor.
Compression connector
This NFPA standard is the "Standard for Electrical Safety in the Workplace" and serves as the primary companion to the NEC for safety procedures.
NFPA 70E
This "holding" or "sealing" contact is wired in parallel with the Start button to keep the coil energized after the button is released.
500: Seal-in contact (also called Auxiliary or Holding)