• Can 2 pole breakers supply 2 circuits

    Say for example, you have a 120/240 V, 2 pole, 20 A breaker. Does the NEC allow this breaker to serve 2 separate 120 V circuits?
    last modified by tgammonphd
  • NFPA 79 18.2 Ground Continuity Tester - Need help choosing a unit

    Can someone please recommend a ground continuity tester for me? Specifically one that can be used to test machine panels.   Section 18.2 of NFPA 79 says: 1) Use an impedance measuring device, take into account...
    last modified by pwalos
  • metallic conduits for pv under roof sheathing

    In search of any reference to installing residential pv system and fastening metallic conduit to and distance required from underside of wooden roof sheathing.
    last modified by mkidwell
  • Cell tower structural work

    I have existing monopole tower for antenna which is grounded and bonded.   Now the structural engineer is going to place long shaft metal plate metallic on each side of the monopole tower by drilling holes in t...
    last modified by apurvadave
  • NFPA 70e Restricted Approach Boundary Question

    NFPA 70e Question: Note ‘a’ to Table 130.4(D)(a) directs the user to use a voltage level of the phase-to-ground voltage times 1.732 when determining the limited and restricted approach boundaries for singl...
    last modified by david.gildersleeve
  • NFPA70-E frequency of Arc Flash studies

    I work for a water district in southern California. I recently paid an engineering firm to complete Arc Flash studies on 20 sites. If in 5 years there are no changes to the equipment. do I need to have a complete Arc ...
    last modified by calhounm
  • Power Cord Length

    In an Operating Room setting, is there a limit to the length of the power cord for any piece of medical equipment?  Thank you!
    last modified by bensonto
  • 480 VAC VFD Power - Do I need an Enclosure & Disconnect?

    Hi,   I work for an equipment manufacturer.  For a machine we are building, I have a VFD for an Exhaust Blower that requires 480 VAC 3-phase 6 amps.  The VFD is designed so that it can be mounted on a ...
    last modified by pwk@kraemerkoating.com
  • NEC 2020 not available in PDF!

    It is extremely disappointing that unlike NEC 2017 and its handbook, the NEC 2020 edition and its handbook are not available in PDF format that you can store on your computer as a digital resource and access it a...
    last modified by nikunj.shah
  • NEC 210.71

    For an existing conference room where the Architect required adding an outlet, the plan check person has required outlets as per this article, which requires quantity as in a residence.  In addition, it requires ...
    last modified by j_w_hines
  • 2017 NEC 680.7

    Does NEC 680.7 apply to factory and field installed lugs, the way I read it is the first sentence would apply to factory lugs and the second sentence would apply to field installed lugs. 
    last modified by mdemps3
  • AFCI for Dishwasher ?

    Pa started following the 2014 NEC so my questions is 1) 210.12(A) - does a dishwasher for a dwelling require AFCI protection if on a dedicated circuit (I know it needs GFCI protection) 2) same question, how about a ...
    last modified by gk1226
  • emergency ATS connected load side of optional ATS

    I am reviewing plans that specify an emergency system and a optional system, the generator has 2 breakers one for each system, but the optional system ATS is specified to be installed to re-feed the entire existing 80...
    last modified by mdemps3
  • Table 310.16 vs. Article 400 for a 3-conductor VFD cable?

    Hi,   I am working on a project in which I will be using a VFD to drive an AC motor.  For the motor power cable from the VFD to the motor, I am planning to use a cable with a braided shield that is specifica...
    last modified by pwk@kraemerkoating.com
  • Working 120v Live

    When working 120Volt Circuits live Receptacles, switches what PPE is required?
    last modified by justin.grantham
  • 240.21 feeder tap directly to utilization equipment?

    Since the 2014 edition, 240.21(B)(1)(1)(b) has allowed a 10 ft feeder tap to terminate on "equipment containing an overcurrent device" as an alternative to terminating directly on an OCPD.   I would like to conn...
    last modified by cfharr
  • qualified observer

    I have a question.  If there is a crew going out to do some  electrical maintenance. But only one member of the crew is a qualified electrician. do the other people assisting him need to have CPR and other ...
    last modified by jrendon6861
  • What is the permissible gap of an opening for a ceiling product or tile when running wires though a tile into a Ceiling that is being used as a plenum?

    There is a product that we want to install in a ceiling in a Healthcare facility and understand the requirements of firestopping for cables but what is the permissible gap for an opening to limit the spread of sm...
    last modified by safedesign1
  • 2020 NEC Definition

    I have a question on the 2020 NEC code – definition of a term.  In Article 100 (70-35)  there is a definition for “Dwelling Unit”.  It states: A single unit ….. My question is ...
    last modified by apshulick@ieee.org
  • Fire Fighting Pump Requirments

    Hi, I need fire fighting pump requirements according to NFPA please help me about it.   Thanks 
    last modified by abrar.b