Electrical Systems & Equipment Flashcards
7 cards from real NECA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Systems & Equipment flashcards as text
Which insulation type is rated for use in wet locations and direct burial?
Answer: USE-2
USE-2 (Underground Service Entrance) cable is rated for wet locations, direct burial, and use as service entrance conductors.
A panelboard rated 42 circuits maximum currently has 40 breakers installed. How many single-pole spaces remain?
Answer: 2
42 maximum minus 40 installed leaves 2 available single-pole circuit spaces.
What type of grounding electrode is the MOST preferred by the NEC when available?
Answer: Metal underground water pipe
The NEC lists metal underground water pipe first in the grounding electrode hierarchy because it provides excellent earth contact over a large area.
What is the minimum depth for installing rigid metal conduit (RMC) under a concrete slab that is not subject to vehicular traffic?
Answer: 0 inches (none required)
RMC installed under a concrete slab with no vehicular traffic requires no minimum cover per NEC Table 300.5.
What does a power factor of 0.8 lagging indicate about an electrical load?
Answer: The load is inductive and current lags voltage by 36.87°
A lagging power factor indicates an inductive load where current lags behind the voltage waveform.
Which NEC article covers the installation of electric motors and their associated controls?
Answer: Article 430
NEC Article 430 covers motors, motor circuits, and controllers including wiring, protection, and control requirements.
When sizing a feeder for a non-continuous load of 80A and a continuous load of 60A, what is the minimum conductor ampacity required?
Answer: 155A
Continuous loads are multiplied by 125%, so: 80A + (60A × 1.25) = 80 + 75 = 155A minimum ampacity.