ungrounded conductor
#1
03-25-16, 07:40 PM
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ungrounded conductor
The NEC doesn't permit the use of white or gray conductor insulation for ungrounded conductors in a raceway, even if the conductors are permanently re-identified 2008 NEC 200.7 (c) I would like to have this explained in layman's terms but the background for this is, I installed a 240 volt heater with a single phase thermostat. I put in a 20 amp double pole breaker and ran 12/2 wiring to the heater. Excuse me if I get any of the terminology wrong. As far as I understand it I don't have a neutral, the neutral is now an ungrounded conductor as well as the black. I ran it from the main panel thru a conduit(raceway) into the basement. Does the code quoted above have reference to anything I've done and should not have done. If it is something I should not have done, how do I correct it seeing that I have to run the wire thru a conduit. Also, the NEC also makes reference to a disconnect near the heater. What type of disconnect would satisfy the NEC for this size heater?
#2
03-25-16, 08:27 PM
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In the U.S. the NEC permits the use of 2-conductor cable for 240 volts and it is what is commonly used (Canada varies). The NEC says when a white in a cable is used as an ungrounded conductor it must be remarked red or black or any color but (white), gray or green. This can be done with bands* of colored tape, permanent felt tip marker or colored liquid insulation. (Old books also suggest paint.)
*I suggest distinct bands of tape not wrapping it with tape because if you wrap it someone might think it was a repair but that is personal opinion.
*I suggest distinct bands of tape not wrapping it with tape because if you wrap it someone might think it was a repair but that is personal opinion.
#3
03-25-16, 09:17 PM
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As far as I know.... a disconnect for a heater is only required if it has a fan in it.
Baseboard heat does not require a disconnect means.
Baseboard heat does not require a disconnect means.
#4
03-25-16, 10:38 PM
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Ray, I did read the NEC rule that allows it as long as it is marked as such. I was more concerned with "The NEC doesn't permit the use of white or gray conductor insulation for ungrounded conductors in a raceway" I don't know what that refers to. Since I'm using the 'white" as an ungrounded conductor and it is running thru a raceway (conduit) I would think it applies to me, yet it doesn't make sense. The only difference in the two is the "raceway." Also, PJ, I have to check whether my heater has a fan. If it does, do you know what type of disconnect is suitable? Thanks to both for your answer.
#6
03-26-16, 08:43 AM
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The NEC does not allow the identifying of a white as an ungrounded conductor in a raceway because it is a raceway. You should be able to add the proper color wire by removing/installing a new wire. You can not install a new wire in a cable which why it is allowed in cables.
A two pole snap switch would be fine as a disconnect.
A two pole snap switch would be fine as a disconnect.
#7
03-26-16, 12:03 PM
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Since I'm using the 'white" as an ungrounded conductor and it is running thru a raceway (conduit) I would think it applies to me, yet it doesn't make sense.
#8
03-26-16, 05:39 PM
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I think my problem is that I use "cable" and "wire" as interchangeable terms when they have a different meaning in the business. I ran the 12/2 cable thru the conduit, no more than 6 feet before it entered the house. I will mark the white as hot on both ends. Again, thanks.
#9
03-27-16, 06:23 AM
If you run a manufactured cable through a (fat) conduit or lay it in a trough (cable tray), amidst other wires and cables, then the cable rules still apply for it.
If you assemble a cable yourself using individual conductors (such as THHN) and a sheath, say, similar to BX cable then the sheath is treated as a raceway. You may not thread through a white wire and use that as a neutral.
If you assemble a cable yourself using individual conductors (such as THHN) and a sheath, say, similar to BX cable then the sheath is treated as a raceway. You may not thread through a white wire and use that as a neutral.
