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  1. #1
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    Default Just seems something is missing......

    Nice 200 amp Square D load center upgraded in 2006 to a 1956 home.
    Seems like something was left in the truck! I checked the city permits and the permit had expired which means no inspections were ever done.

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  2. #2
    John Steinke's Avatar
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    Default Re: Just seems something is missing......

    I don't see it.

    BTW ... vhat voltage did you measure at the panel?


  3. #3
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    Default Re: Just seems something is missing......

    Quote Originally Posted by John Steinke View Post
    I don't see it.
    Glad I'm not the only one.

    Department of Redundancy Department
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  4. #4
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    Default Re: Just seems something is missing......

    I didn't see it either! I wanted to see a grounding conductor in the panel.
    I guess just screwing it to the brick is sufficient.

    John, I don't measure voltage. But I figure since it has 2 120's I expect 240?


  5. #5
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    Default Re: Just seems something is missing......

    Does that show the old triplex still attached under the soffit?


  6. #6
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    Default Re: Just seems something is missing......

    Dang Jim,
    You must have blown that picture up 800%. There is a hole in the brick where the old wiring was cut off. I just threw in the 2nd picture to show the absence of a nice copper wire going to the driven ground rod (which did exist) although my picture is a little high.


  7. #7
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Gary Burnett View Post
    I guess just screwing it to the brick is sufficient.
    Well, since the exterior is touching ground... But, would you want to say the electrical system is "bricked" instead of grounded?

    Department of Redundancy Department
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  8. #8
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    Default Re: Just seems something is missing......

    With 30 current carrying conductors going down into the raceway there is a problem which needs to be addressed by derating, and, being as that raceway is outside, it also needs to be derated for your highest ambient temperature you ever get.

    If it ever gets over 96 degree F outside (96 to 104) then that needs to be derated to 0.91.

    If the outside temperature only gets to 85 degrees F (87-95), then derate to 0.96.

    Then, if there are 30 conductors (21-30) you would need to derate further to 0.45, and if 31 conductors (31-40) you would derate to 0.40.

    An example would be 12-2 NM-B starting with a derating ampacity of 30 amps:

    30 x 0.91 = 27.3 amps x 0.45 = 12.3 amps, which is allowed to be on a 15 amp breaker ... unless there is more than one receptacle on the circuit, and it would then not be allowed to even be on a 15 amp breaker.

    Based on your photo, not only do you not have any 20 amp circuit there, you do not even have any 15 amp circuits.

    Jerry Peck, Construction / Litigation Consultant
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  9. #9
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    Default Re: Just seems something is missing......

    Well darn it Jerry,
    I told them to replace the 50 amp breaker at the top left with a 30 amp since the AC unit said max 30 amp. Guess I should tell them to put in a 75 amp and up the wire size!!!
    It gets a lot hotter than 104 around here and a lot of the installations are pretty similar to this one with conductors in conduit/raceways over 24". I know the NEC has the derating for the multiple conductors in raceways & conduit but it doesn't look like anyone takes that too seriously.
    Do they get any credit for spreading out really far when the exit the raceway?
    Why is it called a raceway if it really is a bottleneck?
    Sorry I couldn't use any of the icons...........seems you and A.D. have used up the September allotment.


  10. #10
    Ted Menelly's Avatar
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Gary Burnett View Post
    Nice 200 amp Square D load center upgraded in 2006 to a 1956 home.
    Seems like something was left in the truck! I checked the city permits and the permit had expired which means no inspections were ever done.

    Just curious Gary

    Is this a paid for inspection and do you do such things as check for permiting on inspections you do ?


  11. #11
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Gary Burnett View Post
    Guess I should tell them to put in a 75 amp and up the wire size!!!
    Nope. Keep the smaller breaker size, just up-size the wires.

    It gets a lot hotter than 104 around here
    Then instead of using the 0.91 multiplier, you would use the next one up, 0.87 for ambient of 105-113.

    and a lot of the installations are pretty similar to this one with conductors in conduit/raceways over 24".
    They are all wrong, then.

    I know the NEC has the derating for the multiple conductors in raceways & conduit but it doesn't look like anyone takes that too seriously.
    They should, and if you start pointing it out, they may eventually work toward that end.

    Do they get any credit for spreading out really far when the exit the raceway?
    Nope.

    The worst case ambient is used, combined with the worst case bundling/lack of maintaining spacing.

    Jerry Peck, Construction / Litigation Consultant
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  12. #12
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    Default Re: Just seems something is missing......

    Ted,
    I have this web site that allows me to look at permits for the city of Dallas.
    I sometimes use it to try to anticipate what the inspection will be like when I get there and sometimes I use it after the inspection to see why things don't look right. Wish they had one of these sites for each of the cities we work in so things would be a little easier. I think my link bypasses the login so I type in the address and hit search. When I go to the main menu it asks for a login.

    Give it a shot when you do inspections in the City of Dallas. Type the street number at the right upper box and the street name in the lower box and hit SEARCH. Look at the boxes at the top for permits. Quite revealing.
    I'm just a regular ol inspector like you........hope to get paid for all of 'em.

    Dallas Contractor - Address Search


  13. #13
    Garry Blankenship's Avatar
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    Default Re: Just seems something is missing......

    Not seeing any ground wire. Not seeing any strapping of the service mast. The strike nob on the roof is over 18", ( I think ), and that mast should be back guyed and since that PVC pipe is over 18" , ( again I think ), it is not considered a "nipple" and like JP mentions technically those wires should be derated. For reasons I do not know the derating thing is virtually never called in residential work.


  14. #14
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Garry Blankenship View Post
    For reasons I do not know the derating thing is virtually never called in residential work.
    Laziness on the inspectors because they were used to doing it that way when they did it and they have likely not paid attention to other code items either.

    Jerry Peck, Construction / Litigation Consultant
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  15. #15
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    Default Re: Just seems something is missing......

    The mast needs a back guy? Why?

    NM-B isn't allowed in conduit (or anywhere else) outside the structure as this is considered a wet location.

    NM-B is allowed to enter a panel in conduit only in specific circumstances, only one of which out of several required of are present here. NM-B is supposed to be secured to the panel where it enters the panel (in other words you have to use cable clamps/connectors of some sort) with a maximum of however many cables the connector is rated for, usually two.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  16. #16
    Garry Blankenship's Avatar
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Bill Kriegh View Post
    The mast needs a back guy? Why?

    NM-B isn't allowed in conduit (or anywhere else) outside the structure as this is considered a wet location.

    NM-B is allowed to enter a panel in conduit only in specific circumstances, only one of which out of several required of are present here. NM-B is supposed to be secured to the panel where it enters the panel (in other words you have to use cable clamps/connectors of some sort) with a maximum of however many cables the connector is rated for, usually two.
    Not sure, if NEC or WA St, but if the strike nob/point is more than 18" above the roof penetration, the mast must be back guyed. The exact dimensions can be verified, but the principle is obvious. How much conduit can you extend w/o support and expect it to hold up w/ the weight of say 150' of O/H wire plus wind shear w/o bending ? Pretty sure NM cable is OK most anywhere in conduit. I know the conductors inside the NM sheath are, so doubt any concern w/ the sheath. Never seen an inspector call NM cables bundled through a conduit nipple; no "listed" connector. Not sure what NM-B is.


  17. #17
    Robert Meier's Avatar
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    Default Re: Just seems something is missing......

    The NEC states that the mast must be of adequate strength or that bracing is required to withstand the strain imposed upon it by the drop.

    230.28 Service Masts as Supports.
    Where a service mast is used for the support of service-drop conductors, it shall be of adequate strength or be supported by braces or guys to withstand safely the strain imposed by the service drop. Where raceway-type service masts are used, all raceway fittings shall be identified for use with service masts. Only power service-drop conductors shall be permitted to be attached to a service mast.
    NM cable is not permitted in conduit in wet locations, which would include the inside of any conduit installed outdoors. Indoors it can be run into a panelboard through one large raceway if all of the conditions of 312.5(C)Exception are met.


  18. #18
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Garry Blankenship View Post
    Not sure, if NEC or WA St, but if the strike nob/point is more than 18" above the roof penetration, the mast must be back guyed. The exact dimensions can be verified, but the principle is obvious. How much conduit can you extend w/o support and expect it to hold up w/ the weight of say 150' of O/H wire plus wind shear w/o bending ? Pretty sure NM cable is OK most anywhere in conduit. I know the conductors inside the NM sheath are, so doubt any concern w/ the sheath. Never seen an inspector call NM cables bundled through a conduit nipple; no "listed" connector. Not sure what NM-B is.
    Must be a local rule. Un-guyed masts 3 and 4 feet above a roof are pretty common.

    NM-B is NOT permitted in conduit outside. NM-B isn't permitted in wet locations, conduit outside is considered a wet location.

    334.112 Insulation. The insulated power conductors shall be one of the types listed in Table 310.104(A) that are suitable for branch-circuit wiring or one that is identified for use in these cables. Conductor insulation shall be rated at 90°C (194°F).
    Informational Note: Types NM, NMC, and NMS cable
    identified by the markingsNM-B, NMC-B, and NMS-B meet this requirement.

    334.12 Uses Not Permitted.
    (B) Types NM and NMS. Types NM and NMS cables shall not be used under the following conditions or in the following locations:
    (4) In wet or damp locations

    300.9 Raceways in Wet Locations Above grade. Where
    raceways are installed in wet locations above grade, the interior
    of these raceways shall be considered to be a wet location.

    Outside is considered a wet location

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  19. #19
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    Default Re: Just seems something is missing......

    This thread was over 2 years old, until yesterday.

    All answers based on unamended National Electrical codes.

  20. #20
    Garry Blankenship's Avatar
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Bill Kriegh View Post
    Must be a local rule. Un-guyed masts 3 and 4 feet above a roof are pretty common.

    NM-B is NOT permitted in conduit outside. NM-B isn't permitted in wet locations, conduit outside is considered a wet location.

    334.112 Insulation. The insulated power conductors shall be one of the types listed in Table 310.104(A) that are suitable for branch-circuit wiring or one that is identified for use in these cables. Conductor insulation shall be rated at 90°C (194°F).
    Informational Note: Types NM, NMC, and NMS cable identified by the markingsNM-B, NMC-B, and NMS-B meet this requirement.

    334.12 Uses Not Permitted.
    (B) Types NM and NMS. Types NM and NMS cables shall not be used under the following conditions or in the following locations:
    (4) In wet or damp locations

    300.9 Raceways in Wet Locations Above grade. Where
    raceways are installed in wet locations above grade, the interior



    of these raceways shall be considered to be a wet location.

    Outside is considered a wet location
    Need some help here from JP or ? I just recently saw an illustrated code program example showing NM cable on an exterior wall inside conduit on this site, but cannot find it. The conductors inside the NM sheath, ( THHN ), are listed for wet locations. NEC 334.10, (B), (1) allows NMC is moist or damp locations and 334.12, (1) Has an exception that allows NM, NMC & NMS use in Type I & II construction when installed in raceways. What is Type I & II construction ? You add that up and it makes no sense to disallow NM cables in outside conduits. Especially when you can pull them out, strip off the sheath, pull them back in and your legal. I have seen it used and have used it in conduit and never seen it called by an inspector. I know I would never call it because those conductors have better protection than non-sheathed wires, but cannot argue w/ Bill's serpentine NEC path disallowing same in outside conduits. 334.10, (B), (1) allows moist & damp locations and 334.12, (B), (4) disallows damp or wet locations ??? What am I missing ?


  21. #21
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    Default Re: Just seems something is missing......

    The conductors in NM-B are not labeled so code-wise you cannot say that they are THWN/THHN so they cannot be used as such. Also NM-B cannot be striped of its sheath as it is a listed assembly. Removing the sheath just gives you un-listed parts.

    Try this for construction types.

    http://www.knoxcounty.org/fire/pdfs/...nstruction.pdf

    All answers based on unamended National Electrical codes.

  22. #22
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Garry Blankenship View Post
    Need some help here from JP or ? I just recently saw an illustrated code program example showing NM cable on an exterior wall inside conduit on this site, but cannot find it. The conductors inside the NM sheath, ( THHN ), are listed for wet locations. NEC 334.10, (B), (1) allows NMC is moist or damp locations and 334.12, (1) Has an exception that allows NM, NMC & NMS use in Type I & II construction when installed in raceways. What is Type I & II construction ? You add that up and it makes no sense to disallow NM cables in outside conduits. Especially when you can pull them out, strip off the sheath, pull them back in and your legal. I have seen it used and have used it in conduit and never seen it called by an inspector. I know I would never call it because those conductors have better protection than non-sheathed wires, but cannot argue w/ Bill's serpentine NEC path disallowing same in outside conduits. 334.10, (B), (1) allows moist & damp locations and 334.12, (B), (4) disallows damp or wet locations ??? What am I missing ?

    Is it this one from Mike Holt?



    He has many more graphics here:

    Mike Holt


  23. #23
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Garry Blankenship View Post
    Need some help here from JP or ?
    Bill, Jim, and Robert are correct.

    NM cable is allowed to go from inside the structure, through the wall, and terminate in a junction box on the outside of the wall ... but NM cable is not allowed to continue on any further than directly at the outside of that wall at that junction box.

    That is because NM cable is not allowed to be used in wet locations, and the inside of a raceway (conduit) is considered to be a wet location when installed in wet locations (outside is a wet location).

    There are various drawings which were semi-correct but are no longer correct. By "semi-correct" I mean that they were one person's interpretation of what the code said, or did not say, and with changes and clarifications in the code, those drawings may no longer be correct. Happens to all of us - the drawings need to only be used in reference to the code it is referencing as different editions of the code *may* contain revised wording.

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  24. #24
    Lisa Simkins's Avatar
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    Default Re: Just seems something is missing......

    Walls! An residential electrical panel outside is verboten in Canada.


  25. #25
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Jerry Peck View Post
    Bill, Jim, and Robert are correct.

    NM cable is allowed to go from inside the structure, through the wall, and terminate in a junction box on the outside of the wall ... but NM cable is not allowed to continue on any further than directly at the outside of that wall at that junction box.
    I disagree. In non-protected locations (protected locations under cover are damp, i.e. subject to temperature differentials, condensation, perhaps) NM-B should not be installed beyond the building finish. In the wall, flush, semi flush, perhaps, not on the wall, not presently.

    Who manufactures Listed (for the US market) a Type NMC Cable Assembly? otherwise moot if not manufactured and Listed.

    Raceways outside of buildings, through thermal envelope, etc. subject to temperature changes, condensation, shall be sealed. Can't seal the sheath.

    NM-B is not UF.

    THHN is not water resistant/wet location rated, THWN is.

    P.S. The panel should not be mounted "on" the brick wall or brick faced wall, but offset. Semi flush or flush are mounted in the wall.

    P.P.S. The inbound metallic conduit, condulet or fitting from the meter can should be bonded.

    Last edited by H.G. Watson, Sr.; 04-06-2012 at 07:45 AM.

  26. #26
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Lisa Simkins View Post
    Walls! An residential electrical panel outside is verboten in Canada.
    Since when?

    Bond and service disconnect has usually been outside (service panel), 4-wire feeder to interior, N's and G's separated interior as far as I recall.

    You sure its not a regional or local prohibition you are speaking of?

    IIRC each province has autonomy in their adoption and additional restrictions.


  27. #27
    Lisa Simkins's Avatar
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    Default Re: Just seems something is missing......

    HGW, I was overgeneralizing about service panels in Canada, but in my limited experience I have never seen a panel outdoors - in an unconditioned garage yes (an older installation - not ideal), but not on an outside wall.

    I checked a guide to the Ontario Code, (which is based on the Canadian Electrical Code) -> Location of Service Panel - Rule 6-206 "The service equipment must be inside the building served"

    The METER is outside. But it wouldn't make sense to allow the panel to be outside, with freezing/condensation, etc.


  28. #28
    Garry Blankenship's Avatar
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    Default Re: Just seems something is missing......

    Quote Originally Posted by H.G. Watson, Sr. View Post
    I disagree. In non-protected locations (protected locations under cover are damp, i.e. subject to temperature differentials, condensation, perhaps) NM-B should not be installed beyond the building finish. In the wall, flush, semi flush, perhaps, not on the wall, not presently.

    Who manufactures Listed (for the US market) a Type NMC Cable Assembly? otherwise moot if not manufactured and Listed.

    Raceways outside of buildings, through thermal envelope, etc. subject to temperature changes, condensation, shall be sealed. Can't seal the sheath.

    NM-B is not UF.

    THHN is not water resistant/wet location rated, THWN is.

    P.S. The panel should not be mounted "on" the brick wall or brick faced wall, but offset. Semi flush or flush are mounted in the wall.

    P.P.S. The inbound metallic conduit, condulet or fitting from the meter can should be bonded.

    Thanks gents. I have two mistaken assumptions in all this. I've been assuming THHN is good for wet locations for many years, ( my bad, damo OK, wet no ), and I thought that Mike Holt illustration from RM was outdoors, ( another bad ). So I learnt some.


  29. #29
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    Default Re: Just seems something is missing......

    Maybe not too much of an overgeneralization; a service panel on an outside wall would not be approved in BC either. Add rain and more rain to the freezing already mentioned.


    Quote Originally Posted by Lisa Simkins View Post
    HGW, I was overgeneralizing about service panels in Canada, but in my limited experience I have never seen a panel outdoors - in an unconditioned garage yes (an older installation - not ideal), but not on an outside wall.

    I checked a guide to the Ontario Code, (which is based on the Canadian Electrical Code) -> Location of Service Panel - Rule 6-206 "The service equipment must be inside the building served"

    The METER is outside. But it wouldn't make sense to allow the panel to be outside, with freezing/condensation, etc.



  30. #30
    Robert Meier's Avatar
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    Default Re: Just seems something is missing......

    I'm confused, is someone saying that the inside of a panel is a wet location disallowing THHN when the panel is outdoors??


  31. #31
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    Default Re: Just seems something is missing......

    Quote Originally Posted by H.G. Watson, Sr. View Post
    I disagree. In non-protected locations (protected locations under cover are damp, i.e. subject to temperature differentials, condensation, perhaps) NM-B should not be installed beyond the building finish. In the wall, flush, semi flush, perhaps, not on the wall, not presently.
    Actually, we agree as that is what I said too.

    The difference is that you are saying "NM-B should not be installed beyond the building finish" and I am saying "through the wall, and terminate in a junction box on the outside of the wall". The difference is the extra 6" of NM cable required to make the junction within the junction box.

    Raceways outside of buildings, through thermal envelope, etc. subject to temperature changes, condensation, shall be sealed.
    Correct again.

    Can't seal the sheath.
    And you don't need to as the NM cable is clamped in the cable clamp.

    THHN is not water resistant/wet location rated, THWN is.
    Not sure where that came from, but if it came from Jim's post he said "THWN/THHN" and wire dual rated as such (I see it all the time) IS suitable for use in wet location raceways, etc.

    P.S. The panel should not be mounted "on" the brick wall or brick faced wall, but offset.
    P.S. The enclosure is mounted "on" the wall, as in those little 1/4" manufactured in stand-off mounting 'feet' are "on" the wall, which leaves the required 1/4" air space between the back of the enclosure and the surface of the wall.

    Jerry Peck, Construction / Litigation Consultant
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  32. #32
    Garry Blankenship's Avatar
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    Default Re: Just seems something is missing......

    Not wanting to fly in the face of someone that provides so much valuable wisdom to the masses, but there are singularly THHN wires or THWN wires as well as dual rated THHN / THWN wires. One is not necessarily the other. THHN, ( which is used in NM cable ), I have always thought to be good for wet locations, but they are not. The "W" is wet I believe, but it may be for Weather. THHN is good for damp locations, but not for wet locations. The classification of the wires first shown in this threads photo could be endlessly argued for either, ( wet or damp ), because I assume there is a soffit above, shielding the conduit from rain. The "T" is for "Thermoplastic" ~ The "H" is for "Heat", ( 75o C ) ~ "HH" I believe, ( rusty on this ), is High Heat / 90o C ~ The "W" is either Wet or Weather resistent. Regardless "W" means good for wet locations. Hard for me to accept, but THHN is not approved for wet locations. Electricians love THHN wires because you can get more of them in a conduit, even more than THWN wires because the W makes them thicker. R.M. raises an interesting question about the legality of THHN wyrs inside an exterior panel, but I believe it is safe to assume that panel interior is not classified as wet. I assume it is NEMA 3R and rain tight. It's all hair splitting, but good fodder for education.


  33. #33
    Robert Meier's Avatar
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Garry Blankenship View Post
    Not wanting to fly in the face of someone that provides so much valuable wisdom to the masses, but there are singularly THHN wires or THWN wires as well as dual rated THHN / THWN wires. One is not necessarily the other. THHN, ( which is used in NM cable ), I have always thought to be good for wet locations, but they are not. The "W" is wet I believe, but it may be for Weather. THHN is good for damp locations, but not for wet locations. The classification of the wires first shown in this threads photo could be endlessly argued for either, ( wet or damp ), because I assume there is a soffit above, shielding the conduit from rain. The "T" is for "Thermoplastic" ~ The "H" is for "Heat", ( 75o C ) ~ "HH" I believe, ( rusty on this ), is High Heat / 90o C ~ The "W" is either Wet or Weather resistent. Regardless "W" means good for wet locations. Hard for me to accept, but THHN is not approved for wet locations. Electricians love THHN wires because you can get more of them in a conduit, even more than THWN wires because the W makes them thicker. R.M. raises an interesting question about the legality of THHN wyrs inside an exterior panel, but I believe it is safe to assume that panel interior is not classified as wet. I assume it is NEMA 3R and rain tight. It's all hair splitting, but good fodder for education.
    Yes the "W" designation for conductors is for wet locations. Actually according to Table 5 in Chapter 9 of the NEC, THHN and THWN have the same outer diameter. If you're comparing THW and THHN then you're absolutely correct there is a big difference in conductor diameter and greater fill for the THHN.

    Back to the designation of the inside of a panel in a wet location. The inside of the panel is not a wet location, nor for that matter is the inside of a box located in a wet location. The inside of a raceway is a wet location because the NEC tells us it is.


  34. #34
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Jerry Peck View Post
    Not sure where that came from, but if it came from Jim's post he said "THWN/THHN" and wire dual rated as such (I see it all the time) IS suitable for use in wet location raceways, etc.
    Quote Originally Posted by Garry Blankenship View Post
    Not wanting to fly in the face of someone that provides so much valuable wisdom to the masses, but there are singularly THHN wires or THWN wires as well as dual rated THHN / THWN wires.
    No one in the posts above has said that THHN and THWN are not singularly rated, only that there is THHN/THWN and that there is a lot of it, and that "(I see it all the time)" ... followed with that "IS suitable for use in wet location raceways, etc.".

    Jerry Peck, Construction / Litigation Consultant
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  35. #35
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    Default Re: Just seems something is missing......

    Not sure where that came from,
    THHN is not water resistant/wet location rated, THWN is
    Quote Originally Posted by Jerry Peck
    Not sure where that came from
    I was responding to assertions in Garry Blankenship's posts full of disinformation and incorrect assumptions. Specifically this post quoted below, and most specifically the two areas which I've highlighted with blue color, bolding and underlining (the area highlighted but not in blue was already addressed/corrected fully by others):

    Quote Originally Posted by Garry Blankenship View Post
    Need some help here from JP or ? I just recently saw an illustrated code program example showing NM cable on an exterior wall inside conduit on this site, but cannot find it. The conductors inside the NM sheath, ( THHN ), are listed for wet locations. NEC 334.10, (B), (1) allows NMC is moist or damp locations and 334.12, (1) Has an exception that allows NM, NMC & NMS use in Type I & II construction when installed in raceways. What is Type I & II construction ? You add that up and it makes no sense to disallow NM cables in outside conduits. Especially when you can pull them out, strip off the sheath, pull them back in and your legal. I have seen it used and have used it in conduit and never seen it called by an inspector. I know I would never call it because those conductors have better protection than non-sheathed wires, but cannot argue w/ Bill's serpentine NEC path disallowing same in outside conduits. 334.10, (B), (1) allows moist & damp locations and 334.12, (B), (4) disallows damp or wet locations ??? What am I missing ?

    Now, regarding your response to my comment "You can't seal the sheath"
    which was
    Quote Originally Posted by Jerry Peck
    And you don't need to as the NM cable is clamped in the cable clamp.
    (emphasis mine)

    I submit my response and that the responsive discussion was in regards to the OP photos and specifically responsive to the subsequently recently revived discussion and in regards to the statements made, again, by old discussion thread reviver with the nom-de-plume Garry Blankenship, not comments made by the original poster Garry Burnet, and certainly not anything said by Jim Port..

    There are no clamps whatsoever in the topic installation (zip ties at neutral groupings and bare grounds, zip ties are not NM cable clamps, and further I know of no NM cable clamp listed for more than two NM cables per clamp):



    The OP photos display some 20-30 NM cables leaving the box via a common KO to plastic conduit - there is/are no clamps, and a clamp upon type NM cable is not a sealing for passage of smoke, fire, air, condensation, water or water vapor, nor for the absorbant packing in NM (not NMC).

    In fact, IF a clamp, strap, staple were administered tight enough to do so (seal against any possiblity of liquid water or water vapor, air, etc. intrusion) around the voids around the conductors within, it would be too tight so as to impinge upon the telfon coating and actually cause a hot spot thus damaging the insulation and causing a hazardous condition - temperature wise, to the conductors, in use. Conditions known to be problematic with both NM and NM-B (of the 60, 75 and 90C varieties, vintages including undersized or non existant grounds, undersized neutrals and full-sized grounds & neutrals), and commonly found defects when NM cables are improperly stapled (pinched).

    Thus (theoretically available) NMC is not allowed in WET locations, only Damp, and that is only permitted due to its lack of packing prone to transport, hold, moisture and its conductors being safe for wet locations.

    I chose to not go into the further disinformation regards GB's representations of 18" being the limit as we all know it is 24", or that the mast is obviously metallic. The plastic conduit/raceway for the circuits would require additional derating for those conductors as it is in excess of 24", is plastic not metallic to free air, and exposed to sunlight in addition to ambient temperatures. The plastic further contributes to heat retention i.e. reducing the ability to put-off heat from the conductors quickly to free air.

    I am surprised a "long time" electrician and electrical contractor (according to Garry Blankenship's recently created profile here) could be so grossly wrong, unfamiliar with, and confused by cable, cord and wire markings, and Chapters 3 & 4 of the NEC. It isn't as though this has changed much in several decades (just moved around from chapter to chapter and section numbering! The heaping, glaring, disinformation, guessing, etc. is so glaring, incredulous, I wonder if it is not intentional in nature as has seen fit to revive/resurect numerous old threads with such...that I question the motivation behind the now apparent pattern of activity.

    The prohibition or the "idea" that one can not strip down or "reverse engineer" a Listed assembly or Listed equipment and utilize unmarked, non-listed or non-recognized componants of or parts of said equipment or assemblies, as though they are individually listed or accepted free-standiing equipment; is also not "new" or news. They are not, never have been, and the practice (modification, alteration, etc.) has never been "legal" to do so without NTL field evaluation, or special approval/acceptance, or some specific model code-modifying language and UL Standard-modifying language special ammendments, language, etc. by the jurisdiction. The Standards as they have been written, developed, changed over the years for such equipment (this case Type NM Cable) has never provided for reverse engineering and use of unlisted conductors to my recollection, reidentying a neutral but not reverse engineer to use as free-standing conductors (completely from end to end), no never, just as to not reverse engineer the conductors from Bx (AC), and other such cable assemblies.

    Type NM or Type NM-B is not for use in damp locations, it is and always has been for normally dry locations. The inside of a NEMA 3R enclosure installed outdoors, exposed to weather, swings of temperature, etc. would not be a dry location, but a damp one, one expected to have an interior "climate" including damp conditions such as near saturated (high RH)ambient air and occasional, albeit negligable condensation collections, but one expected to dry out under normal use conditions quite rapidly and not interfere with the electrical safety and protect against liquid water intrusion.

    I've already said more than I expected or intended to

    Last edited by H.G. Watson, Sr.; 04-07-2012 at 03:27 PM.

  36. #36
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    Default Re: Just seems something is missing......

    Quote Originally Posted by H.G. Watson, Sr. View Post
    Now, regarding your response to my comment "You can't seal the sheath" which was ...
    .
    There are no clamps whatsoever in the topic installation (zip ties at neutral groupings and bare grounds, zip ties are not NM cable clamps, and further I know of no NM cable clamp listed for more than two NM cables per clamp):
    I now understand where that came from, however, I disagree on the aspect that the NM cable is not allowed to be terminated in the enclosure *mounted directly on* the exterior wall.

    In the case of the OP photos, I don't see that as a problem, and if there is a problem there, then the problem is not the NM cable and sheath not being able to be sealed, it is the installation of the NM cables in that raceway - and when that problem is corrected, the other problems would be corrected as well.

    I know some people may say to just seal over those NM cables with the same duct seal used to seal the conduit as you described, however, that only addresses one problem, not the main problem with all those NM cables in that one raceway - meaning that sealing that mess up will not correct the installation problem.

    Other than that, terminating NM cable which is running through the wall into that enclosure, and which is mounted directly to the wall, is not a problem. Not as long as the NM cable is installed correctly, and installing the NM cable in that raceway makes the NM cable not installed correctly.

    Other than terminating the NM in that enclosure (if the NM cable was installed correctly), where I say 'yes' and you say 'no', I suspect we are in agreement on the use and routing of NM cable outside - i.e., not allowed ... period ... whether in a raceway or exposed.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  37. #37
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Jerry Peck View Post
    I suspect we are in agreement on the use and routing of NM cable outside - i.e., not allowed ... period ... whether in a raceway or exposed.
    Yep, as pertains to Type NM and Type NM-B for the US Market, but no as pertains to Canadian Type NMWU Cable (which can be found and is acceptable by ammendment provisions, etc.), for example in modular (a.k.a. pre-fab previously) and manufactured housing imported from Canada in some of the boarder states, especially, for example, in the pacific NW).

    (Which is where, for example, on another thread started by Peter Louis of BC, Canada, with NMWU jumping to a split AC unit got off-track by US based responders.)


  38. #38
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Jerry Peck View Post
    Actually, we agree as that is what I said too.

    The difference is that you are saying "NM-B should not be installed beyond the building finish" and I am saying "through the wall, and terminate in a junction box on the outside of the wall". The difference is the extra 6" of NM cable required to make the junction within the junction box.
    Nope, that's not what I said, and not what you said.

    I am making a distinction with a difference. The covered or protected outside location is a damp location and not technically and constantly exposed as a wet location, and for that, extending through the exterior and insulated wall into a mounted on the wall box still meeting the requirements for the assembly of the wall is permitted. For an outside wet location, exterior wall with for example no overhang, i.e. unprotected, etc. distinction I made earlier...to a box mounted upon the wall (not a semi flush or flush mount) it is not permitted via that transition from the surface into the exterior, outside, wet location (yep that gap between the backside of the "surface mounted- required to be offset) panel or box KO and the exterior wall surface is a wet location when the wall itself is a wet location - i.e. unprotected by overhang, etc.

    Quote Originally Posted by Jerry Peck

    P.S. The enclosure is mounted "on" the wall, as in those little 1/4" manufactured in stand-off mounting 'feet' are "on" the wall, which leaves the required 1/4" air space between the back of the enclosure and the surface of the wall.
    exactly. And that "air space" in an inprotected location on exterior outside wall is a wet location. You will never find a KO at a mount slot.


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    Default Re: Just seems something is missing......

    Quote Originally Posted by H.G. Watson, Sr. View Post
    I disagree. In non-protected locations (protected locations under cover are damp, i.e. subject to temperature differentials, condensation, perhaps) NM-B should not be installed beyond the building finish. In the wall, flush, semi flush, perhaps, not on the wall, not presently.
    Quote Originally Posted by Jerry Peck View Post
    NM cable is allowed to go from inside the structure, through the wall, and terminate in a junction box on the outside of the wall ... but NM cable is not allowed to continue on any further than directly at the outside of that wall at that junction box.
    Quote Originally Posted by H.G. Watson, Sr. View Post
    Nope, that's not what I said, and not what you said.
    That IS what you said, and that IS what I said.

    That may not be what you thought you said, and that may not be what you thought I said, but that IS what you posted (go back and read it for yourself) and that IS what I posted (go back and read that too)

    Quote Originally Posted by H.G. Watson, Sr.
    exactly. And that "air space" in an inprotected location on exterior outside wall is a wet location. You will never find a KO at a mount slot.
    While you will not find a knock out there, you should find a clamp there, and that should all be sealed over (where the NM cable exits the wall as the hole must be sealed, and in sealing the hole, that 1/4" of exposed CLAMP will also be sealed over - there is NO exposed NM cable in that 1/4" air space).

    If you can find NM cable exposed in that 1/4" air space, then the enclosure and the NM cable was not installed properly - *properly* - and that is the condition which I stated was a requirement for NM cable being terminated in that enclosure.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Just seems something is missing......

    As a matter of fact, I have not seen single rated THHN for some years.
    All have been MTW, THHN, THWN.

    As a matter of interpretation, I personally consider a WP enclosure mounted on the exterior of a building to be a dry location inside the box.
    That is the purpose of the box, to keep it dry inside.
    Logically however, I don't know that it would be any less dry in a sealed conduit and entries between two of such boxes.


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    Default Re: Just seems something is missing......

    Quote Originally Posted by bob smit View Post
    As a matter of fact, I have not seen single rated THHN for some years.
    All have been MTW, THHN, THWN.
    Bob,

    That could be why dual rated is what "(I see it all the time)"?

    As a matter of interpretation, I personally consider a WP enclosure mounted on the exterior of a building to be a dry location inside the box.
    That is the purpose of the box, to keep it dry inside.
    Close, but I like your thinking. The NEMA 3R enclosure is not technically a 'dry location' inside the enclosure, but it is designed such that: (bold and underlining are mine)
    - Type 3R Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged by the external formation of ice on the enclosure.
    - http://www.nema.org/prod/be/enclosur...sure_Types.pdf

    Logically however, I don't know that it would be any less dry in a sealed conduit and entries between two of such boxes.
    The 3R enclosure is designed so the ingress of water does not negatively affect the equipment, whereas raceways are not tested for keeping water out, and in fact, raceways are presumed to contain water when in wet locations, either from condensation in the raceway or from water entering in around couplings, fittings, etc.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  42. #42
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    Default Re: Just seems something is missing......

    The bundle of NM cables jammed into the PVC conduit entering the panel enclosure from the bottom is not allowed.

    It (non-flexible raceway used for the protection of the non-metallic cables to a surface mounted panel box) must be from the top of the panel to be using NM.

    NEC 312.5(C) requires that where cable is used, each cable must be secured to the panel enclosure. Because installers repeatedly violated this rule and jammed in multiple nonmetallic cables through a large PVC connector, a new requirement was added to the 2002 NEC that appears now in NEC 312.5(C) Exception. This exception permits cables with entirely nonmetallic sheaths to enter the top of a surface-mounted enclosure through one or more nonflexible raceways not less than 18 in. and not more than 10 ft. in length, provided the following conditions are met:
    (a) Each cable is fastened within 12 in.—measured along the sheath—of the outer end of the raceway.
    (b) The raceway extends directly above the enclosure and does not penetrate a structural ceiling.
    (c) A fitting is provided on each end of the raceway to protect the cables from abrasion, and the fittings remain accessible after installation.
    (d) The raceway is sealed at the outer end using approved means in order to prevent access to the enclosure through the raceway.
    (e) The cable sheath is continuous through the raceway and extends into the enclosure beyond the fitting not less than ¼ in.
    (f) The raceway is fastened at its outer end and at other points in accordance with the applicable article.
    (g) Where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit systems by Table 1 of Chapter 9 of the NEC and all applicable notes thereto.

    2005 made it clear that the interior of raceways outdoors in wet locations are WET locations. NM may not be used in damp or wet locations.

    Brick facing/veneer upon stud construction is not brick construction.

    I believe the answers to your questions are that 334.12(B)(4) does not permit type NM cable to be used in damp or wet locations. Type NM cable cannot be run outdoors even if it is run in a raceway because this is considered to be a wet location. Type NM cable cannot be run in any raceway other than using it as a sleeve in accordance with 334.15(B) and 300.15(C) or in accordance with 334.12(A)(1) Exception. This exception, which was accepted for the 2008 NEC, permits Type NM cable to be run in Type I and Type II construction where it is installed in a raceway permitted for that type of construction. See sections 334.12(B)(4), 334.15(B), 300.15(C) and 334.12(A)(1).

    The exception use for raceway sleeves I believe has been moved from the uses not permitted section (.12) to the uses permitted section (.10) in 2011.

    Obviously a panel box is not a single gang box.

    The sealing is done at the outlet of the raceway not the inlet thus the requirement that both outlet boxes and panel boxes the raceway inlet must be at the top, and extend directly above the panel box.

    The plastic raceway appears also to not be secured and without a fitting at the bottom of the panel box.

    The panel still lacks proper bonding.

    I'm done with this one, it was a dead 2+ y.o. thread.



  43. #43
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    Default Re: Just seems something is missing......

    Quote Originally Posted by H.G. Watson, Sr. View Post
    The bundle of NM cables jammed into the PVC conduit entering the panel enclosure from the bottom is not allowed.
    No kidding?

    That is what we (the rest of has) say when the issue comes up.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  44. #44
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    Default Re: Just seems something is missing......

    Quote Originally Posted by Robert Meier View Post
    THHN and THWN have the same outer diameter. .
    Another mistaken assumption of mine. Yes I had THW involved in my mistaken assumption process. Odd the diameter is the same and the rating different. Must be the thermoplastic composite make-up and probably why the dual rated wire J.P. referenced is so much more common.


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