Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: ungrounded conductors identification

  1. #1
    Join Date
    Feb 2007
    Posts
    11

    ungrounded conductors identification

    Is it acceptible if a single branch circuit starts at the panel board as one color than is changed to another color in a junction box before it gets to the device
    Or is it acceptable if more than one circuit is in the race way.

    It seems to me it could be dangerous to the troubleshooter in the end
    210.5.C does not seem to make this a code violation.
    Any help would be appreciated

  2. #2
    Join Date
    Jun 2004
    Location
    North Central Texas
    Posts
    890
    Quote Originally Posted by PH87
    Is it acceptible if a single branch circuit starts at the panel board as one color than is changed to another color in a junction box before it gets to the device
    Or is it acceptable if more than one circuit is in the race way.
    I know of nothing in the code prohibiting this. Consider where you have 12/3 coming in a j-box with a MWBC and you split off from there with two runs of 12/2, one for each circuit. You have no choice but to connect a black to a red.

    Quote Originally Posted by PH87
    It seems to me it could be dangerous to the troubleshooter in the end
    I never assume that the color of the wire where I am working is the same as the color of the wire from the source. Same thing with type of wire i.e. stranded/solid NM/building wire/MC/SER etc. The rule of "what's on the truck" is always in effect.

    Quote Originally Posted by PH87
    210.5.C does not seem to make this a code violation.
    I agree, it only requires the conductors be identified by system.
    Tony Hill

  3. #3
    Join Date
    Feb 2007
    Posts
    11
    Thanks for covering the color issue.
    Can some one expand on what one nominal voltage system is?

    Where the premises wiring system has a branch circuits supplied from more than one nominal voltage system requires the conductors be identified by system.
    If there is three circuits in one race way of the same voltage or (one branch line) should each branch be identified in a accessible area (such as a circuit number) ?
    I'm trying to understand how the branches should be identified in an accessible area.

  4. #4
    Join Date
    Jun 2004
    Location
    San Francisco, CA
    Posts
    5,465
    Quote Originally Posted by PH87
    Thanks for covering the color issue.
    Can some one expand on what one nominal voltage system is?

    Where the premises wiring system has a branch circuits supplied from more than one nominal voltage system requires the conductors be identified by system.
    The NEC does not really call out colors for ungrounded (Hot conductors) * - Some local codes do, as well as there being standard color codes accepted by the industry... The code here is specific about color of conductors and that they be the same all the way through - BUT IT IS RARELY ENFORCED!!!!
    (* except for high legs)

    The code that you are describing above is simular to another (200.6(D) Grounded Conductors of Different Systems) is specific to installations where you might have two different systems. Either say a (very common) 480/277 and a 208/120 in the same raceway or enclosure. Even if you had two different identical 208/120s but from different transformers. Its purpose is to identify the (grounded) neutrals so they do not get interconnected.

    210.5C was added to the 2005 NEC and contains simular wording to prevent the hots from two different system from being inter-connected.

    For instance, in the past before this code existed, in large buildings with multiple 208/120 transformers all of the conductors of transformer "A" had a colored stipe of say black, then all the conductors of transformer "B" had a red stripe. That way if they ended up in the same box, and they often would - you would know the difference.
    Electric heretic
    It's always gonna be in the last place you look....

  5. #5
    Join Date
    May 2003
    Location
    North Carolina
    Posts
    1,127
    A building may have more than one system present, either from the utility or SDS such as 480/277, 208/120 or 240/120. Conductors must be identified by system. See also 200.6(D) for idenification requirements for grounded conductors.
    John, Chair City, NC
    Technology: Mans best efforts to make things as good as they used to be

  6. #6
    Join Date
    Jun 2005
    Location
    North Logan, Utah
    Posts
    7,939
    In the 2008 NEC if there are multiple systems installed in a building this could be a violation of 210.5(C) depending on how you identify the system. There has be a revision of 210.5(C) to now require the systems to be identified by system and also by phase.

    Here is what the 2008 NEC states:

    (C) Ungrounded Conductors. Where the premises wiring system has branch circuits supplied from more than one nominal voltage system, each ungrounded conductor of a branch circuit shall be identified by phase or line and system at all termination, connection, and splice points. The means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means. The method utilized for conductors originating within each branch-circuit panelboard or similar branch-circuit distribution equipment shall be documented in a manner that is readily available or shall be permanently posted at each branch-circuit panelboard or similar branch-circuit distribution equipment.

    Chris

  7. #7
    Join Date
    Jun 2004
    Location
    San Francisco, CA
    Posts
    5,465
    I'll add more - I'm home sick today.....

    A "system" is everything connected to one transformer as its source.
    Premises Wiring (System). That interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all their associated hardware, fittings, and wiring devices, both permanently and temporarily installed, that extends from the service point or source of power, such as a battery, a solar photovoltaic system, or a generator, transformer, or converter windings, to the outlet(s). Such wiring does not include wiring internal to appliances, luminaires (fixtures), motors, controllers, motor control centers, and similar equipment.
    Emphasis mine...

    "Nominal Voltage" is defined in Art. 100....
    Voltage, Nominal.
    A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts).
    The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment.
    See 220.2(A) * for a list of nominal voltages used in computing branch-circuit and feeder loads.
    Commentary * in the '05 it would be in 220.5A

    It is not uncommon to find more than one system, or more than one voltage in a single Premise (Building or Structure). Many larger commercial buildings will have 208/120, and 480/277. (Black -Red - Blue, and the 277 w/ Brown - Orange - Yellow) Others may have both 240 Delta, and 208Y - both using the same color codes..... (Black-Red-Blue) Still others may have 480 feeder distribution to many 480D-208Y/120 transformers here and there throughout the building. The code IMO does not distinguish that they be of different voltages to warrant being marked differently. (Other opinions may vary on that...) Because even if the same voltage - they would still qualify as separate 'Premise Wiring Systems' by definition.
    Last edited by e57; 01-17-08 at 02:15 PM.
    Electric heretic
    It's always gonna be in the last place you look....

  8. #8
    Join Date
    Jun 2004
    Location
    San Francisco, CA
    Posts
    5,465
    Quote Originally Posted by raider1
    In the 2008 NEC if there are multiple systems installed in a building this could be a violation of 210.5(C) depending on how you identify the system. There has be a revision of 210.5(C) to now require the systems to be identified by system and also by phase.
    ~~~
    Chris
    Chris the '08 also has some stuff in there about banding at the source of MWBC's does it not?

    Even though I think the '08 NEC goes way too far IMO catering to MWBC-phobia - I have been doing that for many years - not just in panels but every box with a little wrap of tape.

    But as far as different systems go - you can easily mark all from one transformer with say a yellow band of tape, and all from the other in hot pink, or what color have you. (Anything but white or green... Some Mexican and Irish guys I used to work with didn't like this because they liked to see the colors of their flag - but use of two of those colors are restricted by Art's 200 and 250.... In the case of the Irish all 3 by 110.15) But still use the regular BRB, and BOY colors for the wire insulation.
    Last edited by e57; 01-17-08 at 02:50 PM.
    Electric heretic
    It's always gonna be in the last place you look....

  9. #9
    Join Date
    Jun 2005
    Location
    North Logan, Utah
    Posts
    7,939
    Quote Originally Posted by e57
    Chris the '08 also has some stuff in there about banding at the source of MWBC's does it not?
    Yes, 210.4(D) has been added:

    (D) Grouping. The ungrounded and grounded conductors of each multiwire branch circuit shall be grouped by wire ties or similar means in at least one location within the panelboard or other point of origination.

    Exception: The requirement for grouping shall not apply if the circuit enters from a cable or raceway unique to the circuit that makes the grouping obvious.

    Quote Originally Posted by e57
    But as far as different systems go - you can easily mark all from one transformer with say a yellow band of tape, and all from the other in hot pink, or what color have you.
    Under the 2005 NEC you would be correct, but under the 2008 NEC you must also identify each phase, of each system, so you couldn't use yellow tape for all phases of one system.

    Chris

  10. #10
    Join Date
    Jun 2004
    Location
    San Francisco, CA
    Posts
    5,465
    I'm not under that blasted '08 code yet but from the wording you posted IMO it would be OK.
    shall be identified by phase or line | and system
    I know there is no comma or split in the sentance - but do not believe it is to mean a seperate color insulation for every phase. I think you could easily run out of rainbow in some buildings without using combinations.

    Conductor insulation of appropriate colors to ID phase, and a band, marking tag etc. to mark system....

    The means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means.
    "Other approved means" - depending on the AHJ could mean anything within your own imagination - so long as it posted somewhere......
    Last edited by e57; 01-17-08 at 03:47 PM.
    Electric heretic
    It's always gonna be in the last place you look....

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •