• Luminaire Weight

    Hello,   What is the maximum weight allowed for a luminaire that is supported by an electrical cord?   For luminaires supported by the screw shell of a lampholder, NEC 410.30 says it can't exceed 3kg or 40...
    created by byronc
  • TEST

    last modified by chiefns830
  • 230/400V Color code

    Hi, my name is Andres, I m a student in electromechanical engineering, I have a doubt about the color code in voltage system, I know that 120/208/240V is: phase A= black, phase B=red, phase C= blue and nuetral=white, ...
    last modified by andrescr54
  • Fire rate cables for LPG leak detection

    I would like to know in which NFPA that requires the cables used in the LPG detection system shall be fire rated cables? is it NFPA 54 or 70? which section exactly, please?
    last modified by eng_mikemo
  • Neutral to earth voltage is high.

    We are facing a peculier problem of Neutral to Earth voltage high.   2MVA Transformer 11KV/0.433KV , Dry type transformer is installed with LT drives.   When Drives are running in Regenerative Mode Neutral...
    last modified by vannamani.a
  • Trough busbar bonding methodology

    I have metallic trough load side of service disconnect means whose enclosure needs to be connected to the equipment grounding conductor. The trough has equipment grounding bus bar inside it.   In attached Figure...
    last modified by apurvadave
  • Main Bonding Jumper Location and Main service Disconnect Residential

    Hey guys,  I'm doing a 3600 sq ft residential job where there is 1800 up and almost 1800 finished basement. The homeowner wants the panel located in the utility room in the basement which is 35' (cable length) aw...
    last modified by jeff_schirmer
  • Transformer Secondary conductor - Overcurrent Protection

    Requirement (2) Transformer Secondary Conductors Not over 3m (10 ft) Long and Requirement (3)Industrial Installation Secondary Conductors Not Over 7.5 m (25ft) Long. We have fulfilled the sub-clauses but which require...
    last modified by cl_yeoh
  • Is it advisable to dress or clamping in ( LT 415V) charged cable?

    LT 15V Cables are already laid and charged in Ladder type cable trays. Is it advisable to dress or clamp the cables in charged condition? Will it be safe? What precaution is to be taken?
    last modified by vannamani.a

    Can pvc coated Mc cable  be used under pavers on a terrace In nyc
    last modified by mungret
  • What are the guidelines for location of an emergency shower or eyewash station in proximity to electrical equipment and enclosures?

    What are the guidelines for location of an emergency shower or eyewash station in proximity to electrical equipment and enclosures? Is the location as it exists dry, damp or wet type (NFPA70 NEC2017 100)?  Will ...
    last modified by wgrayg
  • 70E article 250 Test Instruments

    70E article 250.2(B) requires testing of devices listed in 250.1(1) thru 50.1(14) that is used as primary protection from shock hazards and requires an insulation system to ensure protection of personnel, sh...
    last modified by sunil.ghedia
  • Electrical Outlet in Unconditioned Sunroom

    Hello,   We are building an addition in Devon that is basically just an unconditioned sunroom, only to be used in the spring and summer. It has a good number of outlets already, but there are 4 locations where ...
    last modified by kendraajohanson@gmail.com

    Downtown Philadelphia is 2-phase power.  We need 3-phase for fire pump.   NFPA (2017) 695.3(I) does not permit "phase converters" for fire pumps. The code book does not define "phase converters". My reele...
    last modified by df@thedavincigroupllc.com
  • Paired Generator House Sub-base Fuel Tank Separation

    Situation:  A common configuration for multiple site generators ~3250KW size is to pair the generators together with a common enclosure and put subbase fuel tanks beneath, one per generator, approximately 5220g e...
    last modified by druschc
  • 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
  • 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