code question: 12 volt 18 amp (non class 2) power supply

[andy32821]

Hi Guys,

I think I originally posted this code question in the wrong section.

My intent is to ask one NEC question on a conductor color requirement.

I have a 12 volt DC 18 amp power supply (not class 2) that feeds misc devices throughout a commercial facility via one black conductor and one white conductor. The conductors are installed in EMT.

The negative side of the 12 volt 18 amp (non class 2) power supply output is intentionally grounded in the same way the neutral of a 120 volt AC transformer is intentionally grounded.

Therefore I have one 12 volt DC ungrounded conductor and one 12 volt DC grounded conductor.

My (only) question is:
In this situation: Does the NEC "require" the to be negative (grounded conductor) to be the white conductor?


Thanks,
Andy

 

[S'mise]

Your origional question was 12v 5amps= No

12v 18amps= Yes
Class 1 circuits shall be installed in accordance with Part I of Article 300
and with the wiring methods from the appropriate articles
in Chapter 3.

 

[Twoskinsoneman]

Hi Guys,

I think I originally posted this code question in the wrong section.

My intent is to ask one NEC question on a conductor color requirement.

I have a 12 volt DC 18 amp power supply (not class 2) that feeds misc devices throughout a commercial facility via one black conductor and one white conductor. The conductors are installed in EMT.

The negative side of the 12 volt 18 amp (non class 2) power supply output is intentionally grounded in the same way the neutral of a 120 volt AC transformer is intentionally grounded.

Therefore I have one 12 volt DC ungrounded conductor and one 12 volt DC grounded conductor.

My (only) question is:
In this situation: Does the NEC "require" the to be negative (grounded conductor) to be the white conductor?


Thanks,
Andy

My take is that this would be a Class 1 Power-Limited Circuit. From what I gather since you have grounded one of the the conductors you would be required to follow article 200 for them. I see nothing in 725 to alleviate that...but I look forward to hearing from some of the more....seasoned pros.

 

[augie47]

I'm "seasoned", but not a pro. That being said, in answering the one question, it looks to me that 200.2 woud require the appropriate identification means (white or gray):
200.2 General.
All premises wiring systems, other than circuits and systems exempted or prohibited by 210.10, 215.7, 250.21, 250.22, 250.162, 503.155, 517.63, 668.11, 668.21, and 690.41, Exception, shall have a grounded conductor that is identified in accordance with 200.6. The grounded conductor shall comply with 200.2(A) and (B).

 

[andy32821]

Thanks

Thanks

Thanks Guys,

Andy