Services and Distribution Flashcards
6 cards from real Electrician practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Services and Distribution flashcards as text
What is a 'panelboard' as defined by the NEC?
Answer: A single- or poly-phase unit for controlling circuits by means of overcurrent devices
A panelboard is a distribution assembly containing overcurrent protective devices and buses that distribute power to branch circuits.
What happens when a circuit breaker trips?
Answer: It automatically opens the circuit to interrupt overcurrent
A circuit breaker automatically opens to interrupt current flow when it detects an overload or short circuit condition.
What is the purpose of a transfer switch in an electrical system?
Answer: To transfer load between two power sources such as utility and generator
A transfer switch safely switches electrical loads from the utility supply to a generator or alternate power source.
What size copper conductor is typically required for a 100-amp service entrance?
Answer: 2 AWG
A 100-ampere service typically requires 2 AWG copper service entrance conductors per NEC Table 310.16.
What is the purpose of a neutral bar in a main electrical panel?
Answer: To provide a common connection point for grounded (neutral) conductors
The neutral bar provides a terminal block where all grounded (neutral) conductors connect to complete the circuit back to the source.
Per the NEC, where must the grounding electrode conductor connect to a ground rod?
Answer: Within the first 12 inches of the top
The grounding electrode conductor must be connected within the upper 12 inches (top) of the ground rod per NEC 250.70.