I am having an argument with colleagues on CEC and NEC definitions and requirements for different voltages in the same raceway.
What sparked this is the fact that we do jobs in Canada all the time. All of our cables are TECK90 for 600V motor feeds, installed in cable tray. All motors have PTC thermistors wires back to the motor MCC buckets for monitoring. The PTC wires are always in a separate armored cable. I might be all over the place here so bare with me.
Firstly, I have determined that the NEC does not define cable trays as "raceways" since they are not completely enclosed, whereas the CEC does consider cable trays to be a raceway.
CEC 12-904 (2) indicates that no raceway shall contain conductors of a different source unless they have metal armor around the cables. My interpretation is that we can get away with not using a cable tray barrier as stipulated in CEC 12-904 (2)(b), since utilizing armored cable will conform to CEC 12-904 (2)(a).
However, in the US, they do not use TECK cable in cable trays, they use TC tray cable which does not have the metal armour, so this may be why our US client is telling us we need a divider - the client didn't even know what TECK cable was.
Another thing that I'm not sure of is grouping 24 VDC IO and 120VAC IO in the same multi-conductor TECK cable. We typically never do this, but is it against code to do it? If a TECK cable is technically considered to be a raceway, then we would not be allowed since it would fall under 12-904 (2). If TECK is not considered to be a raceway, then I can't find the code that says I cant group the IO in the same multi-conductor cable.
And now for the main event, we have this job in the US where we have a 480V motor power cable in a direct buried PVC conduit. Can I run the 2-wire cable for the PTC thermistor in the same conduit, or do I need to run a separate conduit? NEC 725.48 (1) states that class 1 circuits can be grouped with power circuits as long as they are functionally associated and both cables are insulated for the highest voltage within said conduit. I'm not sure if this even falls into class 1 but I was not able to find anything else in the NEC.
Can I run the 480V motor cable and the low-voltage thermistor cable in the same U/G conduit?
Thanks!
What sparked this is the fact that we do jobs in Canada all the time. All of our cables are TECK90 for 600V motor feeds, installed in cable tray. All motors have PTC thermistors wires back to the motor MCC buckets for monitoring. The PTC wires are always in a separate armored cable. I might be all over the place here so bare with me.
Firstly, I have determined that the NEC does not define cable trays as "raceways" since they are not completely enclosed, whereas the CEC does consider cable trays to be a raceway.
CEC 12-904 (2) indicates that no raceway shall contain conductors of a different source unless they have metal armor around the cables. My interpretation is that we can get away with not using a cable tray barrier as stipulated in CEC 12-904 (2)(b), since utilizing armored cable will conform to CEC 12-904 (2)(a).
However, in the US, they do not use TECK cable in cable trays, they use TC tray cable which does not have the metal armour, so this may be why our US client is telling us we need a divider - the client didn't even know what TECK cable was.
Another thing that I'm not sure of is grouping 24 VDC IO and 120VAC IO in the same multi-conductor TECK cable. We typically never do this, but is it against code to do it? If a TECK cable is technically considered to be a raceway, then we would not be allowed since it would fall under 12-904 (2). If TECK is not considered to be a raceway, then I can't find the code that says I cant group the IO in the same multi-conductor cable.
And now for the main event, we have this job in the US where we have a 480V motor power cable in a direct buried PVC conduit. Can I run the 2-wire cable for the PTC thermistor in the same conduit, or do I need to run a separate conduit? NEC 725.48 (1) states that class 1 circuits can be grouped with power circuits as long as they are functionally associated and both cables are insulated for the highest voltage within said conduit. I'm not sure if this even falls into class 1 but I was not able to find anything else in the NEC.
Can I run the 480V motor cable and the low-voltage thermistor cable in the same U/G conduit?
Thanks!
