Journeyman Electrician's Low Voltage Systems Flashcards
7 cards from real Journeyman Electrician’s Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Journeyman Electrician's Low Voltage Systems flashcards as text
According to NEC Article 725, which class of circuit is characterized by inherently limited power output, making it safe due to low energy levels?
Answer: Class 2
Class 2 circuits are defined by their limited power output, making them inherently safe with minimal fire and shock hazards per NEC Article 725.
What is the maximum voltage permitted for a Class 1 remote-control or signaling circuit per NEC Article 725?
Answer: 600 volts
NEC 725.41 limits Class 1 circuits to 600 volts, placing them in the same general voltage range as standard power circuits.
Under NEC Article 725, Class 2 and Class 3 conductors shall NOT be placed in the same cable, enclosure, or raceway as which of the following?
Answer: Class 1 circuit conductors
Class 2 and Class 3 conductors must be separated from Class 1 circuits because Class 1 operates at higher power levels that could damage or compromise low-voltage wiring.
Which cable designation is listed under NEC Article 725 for Class 2 circuits in a general (non-plenum, non-riser) installation?
Answer: CL2
CL2 is the listed cable type for Class 2 circuit applications in general (non-plenum, non-riser) installations per NEC Article 725.
A Class 3 circuit differs from a Class 2 circuit primarily because Class 3 circuits:
Answer: Allow higher voltages but with limited current output
Class 3 circuits allow higher voltages than Class 2 (up to 150V) while still limiting current output, making them suitable for applications requiring voltages above 30V.
Per NEC Article 725, Class 1 circuit conductors must be protected by overcurrent protection in accordance with:
Answer: NEC 725.43 based on conductor ampacity
NEC 725.43 specifies overcurrent protection for Class 1 circuits, requiring protection not to exceed the ampacity of the conductors.
Which of the following is a common example of a Class 2 low-voltage circuit typically installed by journeyman electricians?
Answer: Residential doorbell and chime systems
Residential doorbell and chime systems operate at 16-24V AC with limited power from a listed transformer, classifying them as Class 2 circuits under NEC Article 725.