Exam 8: Article 725 of the National Electrical Code; Classification of Circuits

Class 2 or Class 3 conductors may be installed within enclosures including electric light and power circuits provided _________.

Class 2 or Class 3 conductors may be run in the same raceway with Class 1 circuits provided _________.

Multiple Class 2 or Class 3 power supplies can be wired in parallel with each other.

Signaling circuits include _________.

If an equipment failure were to introduce a direct life or fire hazard, the circuit must be reclassified as Class 1.

You have a Rigid PVC conduit (RNC), schedule 80, that is required to hold the following conductors; six -18AWG TFN, ten -18AWG XFF and four -16AWG XF.   Answer the questions below. What size RNC is needed to accommodate the conductors?

The overcurrent protection device for a Class 1 circuits may be rated to _________.

Class 1 circuits, that are not functionally associated, must be separated from power conductors by a solid and firmly fixed barrier.

A power-limited Class 3 power supply must never exceed _________.

A Power-limited Class 1 circuit may operate at a maximum of _________.

Coaxial cable connecting a video camera to a monitor is an example of integral wiring.

Class 1 circuits typically operate from greater voltage and current levels than those of Class 2 or 3 circuits.

Class 2 or Class 3 audio circuit conductors in accordance with section 640.9 of the NEC, __________ occupy the same cable or raceway with other Class 2 or Class 3 remote control or signaling circuits.

In elevators, power-limited circuits must be installed __________.

Instrumentation tray cable can be used as a substitute for Class 3 wiring.

You have a Rigid PVC conduit (RNC), schedule 80, that is required to hold the following conductors; six -18AWG TFN, ten -18AWG XFF and four -16AWG XF.   Answer the questions below. ​ Calculate the total diameter of the XFF conductors.

You have a Rigid PVC conduit (RNC), schedule 80, that is required to hold the following conductors; six -18AWG TFN, ten -18AWG XFF and four -16AWG XF.   Answer the questions below. Calculate the total diameter of the XF conductors.

Power sources for Class 2 or Class 3 circuits may be derived from ________.

Exterior run Class 2 and Class 3 circuits must maintain a minimum separation of _________ from Class 1 electric light and power circuits.

Class 3 power supplies may operate up to a maximum of 1000VA.