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  1. Are these actually 700 or 701 loads? Actually...

    Are these actually 700 or 701 loads? Actually Emergency or Legally required?

    Actually even if 702 loads, the code requires the transfer to be suitable for the indented use and designated and...
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    As additional info, I have found that when the...

    As additional info, I have found that when the AHJ makes a code reference for egress lighting levels, it is usually to the adopted building code first and if it doesn't have a reference, then they go...
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    Exit signs...

    Exit signs
    https://forums.mikeholt.com/showthread.php?t=184338

    For exit lights, it is based on the design of the light fixture and having the code required amount of FC on the floor.
  4. Thread: Battery Cables

    by ron
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    Use DLO that is also RHH insulation rated. RHH...

    Use DLO that is also RHH insulation rated.
    RHH is a recognized insulation type and can be found
  5. Thread: duct bank

    by ron
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    The layout of the 6-4" or 2-4" is important to...

    The layout of the 6-4" or 2-4" is important to how the ampacity of the conductors work out.

    For example, if the ampacity is based on Detail 3 from Annex B, then that would tell you the spacing of...
  6. Thread: Jacket Damage

    by ron
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    A document from Southwire...

    A document from Southwire
    https://img1.wsimg.com/blobby/go/ebc3fdf8-949a-405c-9795-92e4372b83b8/downloads/1c6659pdp_152172.pdf

    from UL...
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    If the utility transformer neutral point (XO) is...

    If the utility transformer neutral point (XO) is grounded, then the utility is considered solidly grounded.
    Is there no neutral brought to the MCC from the transfer switch or no neutral brought out...
  8. According to this link...

    According to this link https://www.ecmag.com/section/codes-standards/seeking-clarity-understanding-arcing-current-versus-bolted-fault-current
    The Doughty Neal Paper states, for a 480V system, the...
  9. Thread: Wireway Sizing

    by ron
    Replies
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    I've seen that done, run along the top of the...

    I've seen that done, run along the top of the server racks. The wireway conductor fill count is then done via typical methods.
  10. Thread: Wireway Sizing

    by ron
    Replies
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    I know that UL has a listing for Metallic outlet...

    I know that UL has a listing for Metallic outlet boxes (QCIT) http://productspec.ul.com/details.php?ccn=QCIT

    406.5 says that a receptacle has to be installed in an identified box or assembly. I...
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    Presumably you have done a load calculation per...

    Presumably you have done a load calculation per Article 220.

    What is the load at the house and how does that equate to the feeder size that you would run at 120/240V single phase or 120/208V 3...
  12. Thread: Wireway Sizing

    by ron
    Replies
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    Sort of like this? ...

    Sort of like this?


    https://www.legrand.us/wiremold/raceway/steel-raceway/multi-channel-raceway/4000-large-raceway/4000-large-raceway.aspx
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    Due to grid switching and the "smart grid", power...

    Due to grid switching and the "smart grid", power can come from lots of directions with changes / development making it hard to keep track, so they often just defer to unlimited primary calculations...
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    This was one of the long answer questions on my...

    This was one of the long answer questions on my PE exam a while back.

    This link has some good bullet points.
    http://www.50hz60hz.com/60hz-motor-running-on-50hz-power-supply.html
  15. Thread: %IZ vs %Z

    by ron
    Replies
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    IZ% Percent impedance. Voltage drop due to...

    IZ% Percent impedance. Voltage drop due to impedance at rated current expressed in percent of rated voltage.
    The formula to convert to short circuit impedance .... I will look for it
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    Depending on how much THD the generator is...

    Depending on how much THD the generator is putting out, the UPS may not recognize it as a valid source and then limit the furnace runtime to the amp-hour rating of the battery (15 minutes or whatever...
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    Rumor is that the next NEC will required SPDs for...

    Rumor is that the next NEC will required SPDs for every service.

    UL 1449 Standard for Surge Protective Devices 4th Edition is the standard to be sure the product is listed to.
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    You are quotable

    You are quotable
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    The Dorm room is likely not a Dwelling unit, but...

    The Dorm room is likely not a Dwelling unit, but the Building probably is a Dwelling unit.

    Interesting issue that has been discussed.

    https://forums.mikeholt.com/showthread.php?t=52807
    ...
  20. Thread: Feeder Disconnect

    by ron
    Replies
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    You don't have to land in a 800A OCPD on the roof...

    You don't have to land in a 800A OCPD on the roof if you can comply with the tap rules in 240. You originate in an 800A OCPD, right?
  21. Thread: 75 vs 90 degrees

    by ron
    Replies
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    Even 1558 SWGR is tested at 75 deg terminations. ...

    Even 1558 SWGR is tested at 75 deg terminations. Without an intermediary termination box at either end, you are stuck at 75 deg ampacities.
  22. Thread: Conductor Size

    by ron
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    Yes, unless there is some type of future growth...

    Yes, unless there is some type of future growth planned.
  23. Thread: Grounding a Genset

    by ron
    Replies
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    Sounds like only 3 wire loads, so you plan to use...

    Sounds like only 3 wire loads, so you plan to use the generator as a separately derived source is good. No need to pull a neutral conductor downstream.

    Review references in Article 250 for...
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    In larger generators, the controller has...

    In larger generators, the controller has protection functions for the alternator, but not "listed" as a protective relay, so the code required breaker protects the feeder and downstream
  25. Thread: Conductor Size

    by ron
    Replies
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    It is a 200A MLO, so 200A worth of feeder unless...

    It is a 200A MLO, so 200A worth of feeder unless of course the fuse is smaller and you can use smaller ampacity wire.
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