1. ATTENTION returning members. If you are coming here from the old forum for the first time, you will need to reset you password. However, we had an email problem getting password reset links set out to a lot of the email addresses. That problem is temporarily rectified but IF you still have an issue, email me direct at info@thebuildingcodeforum.com and I will give you a temporary password.
    Dismiss Notice
  2. Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by clicking here: Upgrades
    Dismiss Notice

Design Limitations of an Electrical Engineer

Discussion in 'Electrical Codes' started by jar546, Dec 2, 2018.

  1. jar546

    jar546 *****istrator

    Joined:
    Oct 16, 2009
    Messages:
    5,853
    Likes Received:
    283
    This is a good one for commercial electrical plan reviewers. Where do you draw the line? Where does the code draw the line?

    You are reviewing a set of prints and associated documentation for the installation of an 800A standby generator for an assisted living facility which means no critical care systems. Of note you see that the engineer specifies that the electrical contractor utilize the tap rule to provide 3 120v 20Acircuits from the ATS to the generator, 1 for the battery charger, one for lighting and a receptacle and one for a block heater. There are no specifics for how or exactly where the ATS is to be tapped other than the tap goes to a safety switch to be mounted outside the enclosure where the conduit feeds to the generator.

    Upon looking at the ATS provided documentation you don't see any integral hardware or fittings that are listed for tapping and again, no specifics from the engineer specifying changing of lugs adding P-Taps in order to complete the design. When questioned, the engineer states that there is a note on the page directing the electrician to tap in accordance with local code requirements.

    How would you handle this situation? Are you OK with an electrician modifying a UL listed ATS used as a service disconnect in order to to this without specs from an engineer? Would you require that the engineer provide more detailed documentation on how to do this?

    OR are you not OK with an engineer modifying a UL listed ATS without info or approval from the manufacturer?

    What say thee?
     
  2. steveray

    steveray Sawhorse

    Joined:
    Nov 25, 2009
    Messages:
    5,898
    Likes Received:
    698
    The engineer can't over rule the listing of an appliance/ piece of equipment......If you allow the engineer to do it, you allow the electrician to do it....
     
  3. ICE

    ICE Sawhorse

    Joined:
    Jun 23, 2011
    Messages:
    7,689
    Likes Received:
    674
    They will need a field evaluation by a NRTL. That's to modify it or to return it to the original condition.
     
  4. jar546

    jar546 *****istrator

    Joined:
    Oct 16, 2009
    Messages:
    5,853
    Likes Received:
    283
    OK, now that I steered this into the current direction, let me ask you these:

    1) Is P-Tapping a conductor inside a panel a modification of a UL listed product?
    2) Is changing the lugs of the main OCPD, ground or neutral bar modifying a UL listed product when the product itself has a listing of lugs for different wire sizes on the label?
    3) Is mounting a safety switch/disconnect on the outside of UL listed equipment such as an ATS considered modifying it? If so, do you hold AC condensing units to the same standard?
     

Share This Page