NETA ETT Level 2 flashcards
NETA ETT Level 2 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Arc flash boundary
- The distance from live parts at which incident energy equals 1.2 cal/cm²; inside it, workers must wear arc-rated PPE appropriate to the calculated incident energy.
- Energized electrical work permit
- A documented authorization required for work on or near exposed energized conductors at 50 V or more, listing hazards, shock and arc boundaries, PPE, and justification for energized work.
- Limited approach boundary
- A shock-protection boundary that unqualified persons may not cross unless escorted by a qualified person; only qualified persons may cross the restricted boundary.
- Lockout/tagout verification
- After isolating and locking a circuit, a qualified person tests for absence of voltage with a meter rated for the circuit, verifying the tester on a known live source before and after.
- Arc-rated PPE
- Clothing and equipment with an arc rating at least equal to the calculated incident energy; nonmelting natural-fiber garments are worn under arc-rated layers to prevent burns.
- Qualified person
- A person who has demonstrated skills and knowledge in electrical safety and construction and has received training to identify and avoid electrical hazards.
- Minimum approach distance
- The closest distance a qualified worker may approach exposed energized parts; it increases with voltage and requires voltage-rated tools and PPE when crossed.
- Shock protection boundaries
- Limited and restricted approach boundaries defined by voltage; limited restricts unqualified persons, while restricted permits only qualified workers using shock protection.
- Ohm's law
- For a resistive circuit, voltage equals current times resistance (V = IR); it is used with power equations P = VI, P = I²R, and P = V²/R.
- Three-phase power formula
- For a balanced three-phase load, real power is P = √3 × line-to-line voltage × line current × power factor; reactive power uses the sine of the angle.
- Power factor
- The ratio of real power in kilowatts to apparent power in kilovolt-amperes, equal to the cosine of the impedance angle for sinusoidal waveforms.
- Transformer turns ratio
- The primary-to-secondary voltage ratio equals the turns ratio; current ratio is inverse, so a step-down voltage transformer steps current up.
- Wye connection relationships
- In a balanced wye, line-to-line voltage is √3 times line-to-neutral voltage, and line current equals phase current.
- Delta connection relationships
- In a balanced delta, line-to-line voltage equals phase voltage, and line current is √3 times phase current.
- One-line diagram
- A schematic using single lines and standard symbols to show major power equipment, buses, and protective devices without every conductor.
- IEEE device number 87
- The ANSI/IEEE device number for differential protection, which compares currents entering and leaving a zone to detect internal faults.
- Insulation resistance test
- A DC test that applies a selected voltage to insulation and measures resistance; readings are temperature-corrected and compared with baseline and minimum acceptance values.
- Polarization index
- The ratio of 10-minute insulation resistance to 1-minute insulation resistance; a low value can indicate moisture, contamination, or insulation deterioration.
- Four-wire resistance measurement
- A Kelvin method using separate current and voltage leads so lead resistance is excluded, giving accurate low-resistance readings of bus joints and contacts.
- Fall-of-potential test
- A ground resistance method using current and potential stakes; the potential probe is placed at about 62% of the distance to the current stake.
- Clamp-on ground tester
- An instrument that measures ground loop resistance by inducing a signal; it requires a bonded system with parallel return paths and is not valid on an isolated electrode.
- True RMS meter
- A meter that calculates the root-mean-square value of a distorted waveform; average-responding meters can underread or overread non-sinusoidal currents and voltages.
- CAT rating
- A safety category and voltage rating for test instruments; the meter's CAT rating must equal or exceed the circuit's category and voltage.
- Phase sequence meter
- An instrument that indicates the order of phase rotation; it is used before connecting motors or parallel sources to verify clockwise or counterclockwise sequence.
- Turns ratio test
- A transformer test that applies voltage to one winding and measures the other to verify ratio and polarity against nameplate values.
- Contact resistance test
- A low-resistance measurement across closed breaker or switch contacts; elevated values indicate pitting, contamination, or insufficient contact pressure.
- Primary injection test
- A test that injects current through a circuit breaker or current transformer primary to verify ratio, wiring, and trip characteristics at realistic currents.
- Secondary injection test
- A test that injects voltage or current into a protective relay's secondary circuits to verify pickup, timing, and logic without primary current.
- Thermographic survey
- An infrared inspection performed under load to find loose connections, overloaded conductors, and other hotspots by comparing phase temperatures.
- Torque check
- Verification that bus and cable terminations are tightened to manufacturer-specified torque using a calibrated torque wrench; loose joints overheat.
- Battery float voltage
- The steady voltage maintained across each cell during float charging; it is checked to detect cells that are weak, sulfated, or overcharging.
- Motor surge comparison
- A test that compares impedance or pulse responses among motor windings to detect turn-to-turn shorts, opens, or winding asymmetry.