Podcast
Questions and Answers
A signal circuit means any electrical circuit that controls any other circuit through a relay or an equivalent device.
A signal circuit means any electrical circuit that controls any other circuit through a relay or an equivalent device.
False
Section 16 covers Class 1 and Class 2 circuits and this includes communication circuits.
Section 16 covers Class 1 and Class 2 circuits and this includes communication circuits.
False
The doorbell circuit installed in a dwelling unit is considered to be a Class 2 circuit when supplied by a 120/24 V, 40 VA Class 2 transformer.
The doorbell circuit installed in a dwelling unit is considered to be a Class 2 circuit when supplied by a 120/24 V, 40 VA Class 2 transformer.
True
An extra-low voltage power circuit may be wired with copper conductors smaller than No. 14 AWG.
An extra-low voltage power circuit may be wired with copper conductors smaller than No. 14 AWG.
Signup and view all the answers
Which of the following would be classified as an Extra-Low-Voltage power circuit?
Which of the following would be classified as an Extra-Low-Voltage power circuit?
Signup and view all the answers
All Class 1 circuits that extend aerially beyond a building must comply with Rules 12-300 to 12-318.
All Class 1 circuits that extend aerially beyond a building must comply with Rules 12-300 to 12-318.
Signup and view all the answers
Conductors for use in a Class 2 circuit shall be of copper.
Conductors for use in a Class 2 circuit shall be of copper.
Signup and view all the answers
A 24 V gas valve-thermostat circuit is an example of a Class 2 low-energy power circuit.
A 24 V gas valve-thermostat circuit is an example of a Class 2 low-energy power circuit.
Signup and view all the answers
Class 1 circuits shall not be run in the same cable with communication circuits.
Class 1 circuits shall not be run in the same cable with communication circuits.
Signup and view all the answers
The control circuit of a forced air furnace, which meets the limitations of a Class 2 circuit, may be wired with copper conductors as small as #19 AWG if the conductors form part of a cable.
The control circuit of a forced air furnace, which meets the limitations of a Class 2 circuit, may be wired with copper conductors as small as #19 AWG if the conductors form part of a cable.
Signup and view all the answers
A 'circuit' is generally considered to be that portion of a wiring installation which is connected to the load side terminals of an AC or DC system and forms a complete path or paths through which electrical current is intended to flow, including utilization equipment.
A 'circuit' is generally considered to be that portion of a wiring installation which is connected to the load side terminals of an AC or DC system and forms a complete path or paths through which electrical current is intended to flow, including utilization equipment.
Signup and view all the answers
A primary battery for a Class 2 circuit is allowed to be rechargeable.
A primary battery for a Class 2 circuit is allowed to be rechargeable.
Signup and view all the answers
In order for a circuit to be classified as a Class 1 Extra Low-voltage Power Circuit it must be supplied from a transformer or other device restricted in its rated output to 1000 VA at 30 V.
In order for a circuit to be classified as a Class 1 Extra Low-voltage Power Circuit it must be supplied from a transformer or other device restricted in its rated output to 1000 VA at 30 V.
Signup and view all the answers
Conductors of Class 2 circuits shall be separated by at least 30 mm from conductors of electric lighting circuits, operating at 300V or less.
Conductors of Class 2 circuits shall be separated by at least 30 mm from conductors of electric lighting circuits, operating at 300V or less.
Signup and view all the answers
It is permissible to supply a Class 1 extra-low-voltage power circuit from a transformer with an output of 60 V, 500 VA.
It is permissible to supply a Class 1 extra-low-voltage power circuit from a transformer with an output of 60 V, 500 VA.
Signup and view all the answers
Conductors of Class 2 circuits shall be separated by at least 50 mm from insulated conductors of non-metallic sheathed cable supplying electric lighting, power or Class 1 circuits operating at 300 V or less.
Conductors of Class 2 circuits shall be separated by at least 50 mm from insulated conductors of non-metallic sheathed cable supplying electric lighting, power or Class 1 circuits operating at 300 V or less.
Signup and view all the answers
The thermostat control circuit of a forced-air furnace fed from a 120/24 V 40VA transformer is usually classified as a Class 1, extra-low voltage power circuit.
The thermostat control circuit of a forced-air furnace fed from a 120/24 V 40VA transformer is usually classified as a Class 1, extra-low voltage power circuit.
Signup and view all the answers
Class 1 Extra Low Voltage Power circuits are circuits which are neither remote control nor signal circuits but which operate at not more than 30 V and where the current is not limited in accordance with 16-200.
Class 1 Extra Low Voltage Power circuits are circuits which are neither remote control nor signal circuits but which operate at not more than 30 V and where the current is not limited in accordance with 16-200.
Signup and view all the answers
Section 16 applies to all circuits, including those that form part of a device.
Section 16 applies to all circuits, including those that form part of a device.
Signup and view all the answers
A Class 2 low energy power circuit may be wired with copper conductors smaller than No. 14 AWG.
A Class 2 low energy power circuit may be wired with copper conductors smaller than No. 14 AWG.
Signup and view all the answers
Study Notes
Class 1 and Class 2 Circuits Overview
- Signal circuits control other circuits using relays or equivalent devices, but this is not classified as a signal circuit under relevant standards.
- Section 16 pertains to Class 1 and Class 2 circuits, including communication circuits, but does not cover communication circuits specifically.
- A doorbell circuit running on 120/24 V with a 40 VA Class 2 transformer qualifies as a Class 2 circuit.
Conductors and Voltage Specifications
- Extra-low voltage power circuits can utilize copper conductors smaller than No. 14 AWG.
- A 30V circuit rated at 500 VA is classified as an Extra-Low-Voltage power circuit.
- Class 1 circuits extending aerially must adhere to specific rules from 12-300 to 12-318.
Class 2 Circuit Characteristics
- All conductors in a Class 2 circuit must be made of copper.
- A 24 V gas valve-thermostat circuit illustrates a low-energy Class 2 power circuit.
- Class 1 circuits cannot share cables with communication circuits.
Wiring and Circuit Definitions
- Control circuits for forced air furnaces can use copper conductors as small as #19 AWG.
- A circuit is defined as the wiring installation connected to the load side of an AC or DC system, completing a path for electrical current flow.
- Primary batteries used in Class 2 circuits cannot be rechargeable.
Class 1 Extra Low-Voltage Power Circuits
- To classify as a Class 1 Extra Low-Voltage Power Circuit, it must be supplied by a transformer limited to 1000 VA at 30 V.
- Conductors of Class 2 circuits must maintain a separation of at least 30 mm from electric lighting conductors operating at 300 V or less.
- It is not permissible to supply a Class 1 Extra Low-Voltage power circuit from a transformer outputting 60 V, 500 VA.
Compliance and Separation Rules
- Class 2 circuit conductors must be spaced at least 50 mm from insulated conductors in non-metallic sheathed cables supplying various electrical circuits.
- The thermostat control circuit for a furnace supplied by a specific transformer is not identified as a Class 1 extra-low voltage circuit.
- Class 1 Extra Low Voltage Power circuits do not encompass remote control or signal circuits but operate at a maximum of 30 V without current restrictions in accordance with existing standards.
Section Applicability
- Section 16 does not pertain to all circuits, specifically excluding those that form parts of devices.
- Copper conductors in Class 2 low energy power circuits can indeed be smaller than No. 14 AWG.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the fundamentals of Class 1 and Class 2 circuits in this quiz. Understand the specifications for signal circuits, voltage requirements, and conductor classifications. Test your knowledge on extra-low voltage power circuits and their characteristics.
