Power Systems Analysis & Troubleshooting Flashcards
7 cards from real NETA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Power Systems Analysis & Troubleshooting flashcards as text
During a partial discharge (PD) test on high-voltage cable, the unit of measurement for discharge magnitude is:
Answer: Picocoulombs (pC)
Partial discharge magnitude is measured in picocoulombs (pC), representing the charge transfer associated with each discharge event.
The reactance component of a transmission line impedance primarily causes:
Answer: Voltage drop proportional to reactive current and line length
Line reactance causes voltage drop that is proportional to reactive (inductive) current and the total reactance of the line.
A three-phase transformer with a Dyn11 vector group designation means the secondary neutral voltage lags the primary by:
Answer: 30 degrees (lagging)
In a Dyn11 transformer, the '11' indicates the secondary voltage phasor is at the 11 o'clock position, representing a 30-degree lag relative to the primary.
When testing a metal-clad switchgear assembly under NETA specifications, which test verifies that ground connections are electrically continuous?
Answer: Low-resistance ohmmeter ground continuity test
A low-resistance ohmmeter (DLRO) test is used to verify that all ground bus connections and structural ground bonds are continuous and within acceptable resistance.
In a load flow study, the bus that serves as the slack (swing) bus is responsible for:
Answer: Balancing real and reactive power mismatch in the network
The slack bus absorbs the difference between generated and consumed power plus losses, balancing the power flow equations for the entire network.
A Doble power factor test on a current transformer (CT) measures the insulation quality between the:
Answer: Primary conductor and the CT core/secondary insulation system
The CT power factor test assesses the dielectric quality of the insulation system between the high-voltage primary conductor and the grounded secondary/core assembly.
When a maintenance technician observes that a vacuum interrupter in a medium-voltage breaker fails a hi-pot test, the CORRECT action is to:
Answer: Replace the defective vacuum interrupter bottle
A vacuum interrupter that fails the dielectric withstand test has lost its vacuum integrity and must be replaced; it cannot be repaired in the field.