• Solar Pole Lighting Voltages

    Hello I am developing a solar pole light for walkways.  It is self contained, contains Lithium Ion batteries, and not connected to the grid.  I am wondering at what voltages (solar panel, battery or LED dri...
    dleverton
    last modified by dleverton
  • Absence of Voltage Testing

    According to the NFPA 70E, when are noncontact test instruments permitted to be used to verify absence of voltage in circuits less than 1000 volts? 
    Steve Benton
    last modified by Steve Benton
  • Operating Generators and NFPA-70E

    I am being challenged by our work group regarding working on a HV generator set (11kV) that is in close proximity to other operating generators at 11kV within a powerstation.  From NFPA-70E Table 130.7(C)(15)(a) ...
    alan.peet
    last modified by alan.peet
  • Electrical Equipment Labeling- QR Code

    Imagine being asked to have a look at a piece of equipment that is having some issues or perhaps you might just be doing periodic maintenance and inspections. The equipment could be any number of types but I’ll ...
    Steve Benton
    created by Steve Benton
  • If we install air aspirating system then there is no need of infra red beam detectors as per standard?

    We have oil rig Manufacturing warehouse of  length 128.12 , width 62.82 and height 13 meters,contractor  has proposed vesda  air aspirating  system, saying that if we install  air aspirating d...
    maqsoodasif17
    last modified by maqsoodasif17
  • charge controllers

    Per 690.72(B), two charge controllers may be required if one diversion controller is part of a PV system. Does anyone know how to check a listing to verify compliance with this code section? I can't find any source, a...
    rwelch
    last modified by rwelch
  • Question about NEC 348.20, FMC Run Length

    Hello All,   I am an trying to find out if the 6 ft rule for FMC has always been in place, or if it was added at some point after the first NEC was released?   Also, if it was added after a certain point, ...
    srpl
    last modified by srpl
  • NFPA 70 for deep well pump application Class 1 Division 2

    I have a project that takes storm water (not sewage) via gravity flow into an underground storage system (all debris has been removed prior to entering storage). This water will be treated via recirculation using...
    jalmaraz
    last modified by jalmaraz
  • light and power circuit in same trunk

    Can i run power  circuit and light circuit in same conduit or trunk of same voltage ?
    maqsoodasif17
    last modified by maqsoodasif17
  • Transformer Bonding conductor size from XO to frame

    What is correct table for sizing the conductor between the Neutral and the transformer frame/enclosure for a dry type indoor 480V-208/120V transformer?  The transformer is part of a premises wiring system, not a ...
    trapp
    last modified by trapp
  • surge protection (SPD)

    If a MCC has a surge protection device in it and if it feeds a panel board and is on a emergency system (generator) does the panel board still a surge protection device to meet the requirements of NEC 700.8.
    aaron.lewin
    last modified by aaron.lewin
  • Does a magnetic flow meter need to be earth grounded.

    aaron.lewin
    last modified by aaron.lewin
  • TEFC motor terminal box.

    Does a TEFC motor terminal box need to be sealed on the inside.
    aaron.lewin
    last modified by aaron.lewin
  • Double Tapping Breakers?

    What type of breakers are available today that will allow "Double Tapping" in a residential breaker panel?
    david.sparkes
    last modified by david.sparkes
  • Pull boxes penetrating walls

    Hi everyone!   We are doing a renovation project and one of our concerns is a pull box penetrating a wall. According to one of the project managers, in Japan's standards, a pull box made of a 1.6mm-thick p...
    ejlsanpedro
    last modified by ejlsanpedro
  • is Field Certificate mandatory for unlabeled equipments?

    Good morning   I have a US vendor who is installin paneld made in Ahmedabad, India. The contract was closed by my mechanical colleague and he didn´t take too much care about mechanical devices, but now I...
    maridul63
    last modified by maridul63
  • Type NM cable in EMT Conduit

    What does the NEC state for running Romex (NM) cable through EMT conduit?  I have always been told it was not permitted, but some quick reading on the web makes me think otherwise.
    lambert.christ
    last modified by lambert.christ
  • Ground outside of device.

    What would be the purpose of the ground being on the outside of the device
    aaron.lewin
    last modified by aaron.lewin
  • Ref : NFPA(NEC) 70 Article 725.49(B).

    NFPA(NEC) 70 Article 725.49(B) pertaining to class 1 cicuit conductors  says "Insulation shall be rated for system voltage and not less than 600 volts" Here I have two queries related to field I/O wiring for PLC...
    jz2018
    last modified by jz2018
  • Garage cable clarification

    Hello, I have a question about a residential garage that I am building. My family is having a detached garage built on our property. It is far from our main house but close to an electrical pole. We plan to have new ...
    jasinb
    last modified by jasinb