Reclassification of Class 2 & 3 Circuits

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JS-Addis

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Article 725.30 (ex 2) allows the reclassification of class 2 and class 3 circuits to Class 1 circuits as long as the wiring methods are in accordance with Part II, Class 1 circuits, among other requirements. In Part II, article 725.46 (ex 1) allows Class 1 circuits to be installed according to the provisions of 725.48 through 725.51.

In article 725.48 (A), "Two or More Class 1 Circuits" allows Class 1 circuits, and I take this means the following: Power-limited, Remote-Control and Signaling circuits, and reclassified Class 2 and Class 3 circuits. Given that assumption, article 725.48 (A) indicates that all the conductors be insulated for the maxium voltage level of any conductor in the cable, cable tray, etc.

So here's my question: Say I have mixture of Class I circuits (maxium voltage of any conductor is 120V w/600v insulation) and I have some reclassified Class 2 circuits (maxium voltage of any conductor 24vdc w/300v insulation(PLTC)). Does the PLTC cable meet the requirement of being insulated for the maxium voltage of any conductor in the cable, cable tray, etc., given that the maxium voltage is 120v? Or does article 725.49 (B), which dictates 600V insulation for Class 1 Circuits override this logic?
 
JS-Addis said:
Article 725.30 (ex 2) allows the reclassification of class 2 and class 3 circuits to Class 1 circuits as long as the wiring methods are in accordance with Part II, Class 1 circuits, among other requirements. In Part II, article 725.46 (ex 1) allows Class 1 circuits to be installed according to the provisions of 725.48 through 725.51.

In article 725.48 (A), "Two or More Class 1 Circuits" allows Class 1 circuits, and I take this means the following: Power-limited, Remote-Control and Signaling circuits, and reclassified Class 2 and Class 3 circuits. Given that assumption, article 725.48 (A) indicates that all the conductors be insulated for the maxium voltage level of any conductor in the cable, cable tray, etc.

So here's my question: Say I have mixture of Class I circuits (maxium voltage of any conductor is 120V w/600v insulation) and I have some reclassified Class 2 circuits (maxium voltage of any conductor 24vdc w/300v insulation(PLTC)). Does the PLTC cable meet the requirement of being insulated for the maxium voltage of any conductor in the cable, cable tray, etc., given that the maxium voltage is 120v? Or does article 725.49 (B), which dictates 600V insulation for Class 1 Circuits override this logic?
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Looks as if 725.49 (B) wins. The wording of "shall be suitable for 600v" is the key.
 
If the maximum voltage level is 120 volts then all conductors would need a minimum insulation value of 120 volts. 600 volt and 300 volt insulation values would meet this requirement. Also I believe that the power supply would have to be designed to accept a class 1 designation. A power supply that stated that it was listed as Class 2 only could not be reclassified as a class 1 wiring power supply.
 
Even if we can reclassify the Class 2 or 3 circuits as Class 1, the rule in 725.48(B)(2) still imposes strict limits on installing the reclassified circuit in with power circuits.
 
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