• Protection of Fire Pump Feeder Circuits

    Section 695.6(A)(2) of the 2017 NEC requires conductors that connect "directly" to an on-site standby generator to comply with all of the following: (a) Independent Routing, (b) Associated Fire Pump Loads (c) Protecti...
    last modified by ron.bethea
  • NFPA-79 Wire Color Code

    The NFPA-79 Wire Color Code is important for any person to quickly identify Circuits.  Consequences of using the wrong Wire Color could be lethal.   The NEC calls out (3) Colors:      * ...
    last modified by rcramereleceng
  • I am trying to apply Table 130.7(C)(15)(A)(a) of NFPA 70e

    I am trying to apply Table 130.7(C)(15)(A)(a) of NFPA 70e to my scenario.  I need to open hinged covers on a control cabinet to reset faults on VFD's occasionally.  These control cabinets usually have 480V c...
    last modified by brian.calvert
  • Listed Equipment Installation

    I am installing milling equipment in a flour mill in the United States but the manufacture of the equipment is European and the equipment itself does not have a Nationally Recolonized Testing Laboratory label on it.&#...
    last modified by bscott.contracting
  • NEC 250.122B EGC Size

    I am trying to understand what base size we are supposed to use when we need to proportionally increase the size of the Equipment Grounding Conductor (EGC) per NEC 250.122B. Let’s say the following scenario: Bre...
    last modified by rafis
  • Supply to Fire Alarm and Protection Panels

    Greetings,   I'm looking to confirm that supply branch circuits to fire alarm and protection panels can be run in raceways with other plant wiring, and need not be segregated. I'm looking at NEC Article 760, an...
    last modified by stepandmit
  • Electrical Panel Lexan Covering Exposed 480VAC

    I worked for 24 years at General Motors and it was common to see exposed 480VAC in electrical panels covered with Lexan glass to prevent accidental contact. We performed arc flash studies and all of our panels were la...
    last modified by zz3l4b
  • Electrical Testing of Medical Equipment

    I am seeking clarification on Medical Equipment testing in Skilled Nursing Facilities. We do not admit patients that truly are  using any life support equipment so our category of risk is very low. An oxygen conc...
    last modified by rrolfe
  • Converting Dedicated 20AMP line to outlet- dishwasher replacement

    Replacing dishwasher, would like to turn dedicated 20 amp line into plug in outlet.  Do I need GFCI outlet?  What are rules on where I can place outlet?  Want to place behind stove.  Ther...
    last modified by smurfsrcute
  • Why can’t I get this GFI to trip?

     I installed a GFCI receptacle to replace an ungrounded two prong outlet. The receptacle still reads ungrounded which is expected, however when I push the test button the GFCI will not trip.   Is the device ...
    last modified by adamskimn
  • AFCI protection for mobile homes

    Not sure if this is the correct place for my question but here goes; can anyone help me to understand why AFCI protection (as outlined in 210.12) for dwelling units is not required in manufactured / mobile homes, whic...
    last modified by diverseelectric
  • NEC 250.122(B)

    In regards to NEC 2014 250.122(B). Assume calculations show that a  370 wire sizing ampacity is required for a feeder, and #500 KCMI copper conductor is selected to feed this load from a 400 amp circuit breaker p...
    last modified by dmatern
  • Paralled Conductors-Derate Q

    I have parallel feeders to a 800 Amp MCC in separate raceways from the distribution breaker.  Does the wire have to be derated according to Table 310.15(B)(3)(a) from NFPA 70 code.  We are having a debate on...
    last modified by matt.rudolph

    ELECTRICAL ROOMS - FIRE RATING I'm looking for required fire ratings of Elec Rms in office bldgs, as well as other bldg types. What is the best manual to research: NFPA 101, NFPA 75, or other? Thanks, jksjim
    last modified by jsworks
  • RTD Wiring Requirement in C1D2 area

    I am installing temperature monitoring and alarm devices in a Class 1 Division 2 area  I'd like to get confirmation of my understanding from other professionals regarding the installation.  The alarm co...
    last modified by jon.sarrocco
  • Access floor and grounding

    Is as access floor required to be grounded?  In an office building, carpeted tiles.  Power under floor in raceway.  Non-stringered flooring spec'd (tiles screwed down at each corner) and ground straps a...
    last modified by bwy
  • NFPA 70 517.31(B) (2014) downstream distribution system

    NFPA 70 517.31(B) (2014) says "one transfer switch and one downstream distribution system shall be permitted to serve one or more branches in a facility with a maximum demand on the essential electrical system of 150 ...
    last modified by dan@spectrumsystem.com
  • Double Tapping Breakers?

    What type of breakers are available today that will allow "Double Tapping" in a residential breaker panel?
    last modified by david.sparkes
  • Does the NEC allow for the use of nonmetallic electric conduits in plenum of a confined space in a building?

    The NEC don't allow for the use of nonmetalic electric conduits in plenum (open space above false ceiling used for return air) in order avoid the convey of smoke and/or fire to other parts of the building. Is this ap...
    last modified by abdulazizabuali
  • Removing cover from electrical panel with dead front in place

    Good Afternoon,    When removing covers from electrical panels but leaving the deadfront in place are employees required to wear Arc Flash protection and follow approach boundaries? This is commonly done fo...
    last modified by safetysaves2019