• MC cable for PV installation

    Article 330.12 prohibits MC cable when exposed to mechanical damage. 690.31(D) allows MC cable when intalled in an area that is not readily accessible.  My client wants to install MC cable across the open roof of...
    created by jeffrey
  • Grounding a residential TV antenna drawing

    Grounding a residential TV antenna drawing.  I was wondering if there was an NEC created or approved drawing on how to properly ground a residential TV antenna?  I see some online from manufacturers, but wan...
    created by antman33
  • 2017 NEC Section 300.10,250.96,20.118(6) Electrical continuity

    What is the meaning of electrical continuity as far as bonding and grounding requirements per NEC?   For example: 30" length of 4" diameter of LFMC on one end of pipe then connects to 60 feet of 4" diameter of r...
    last modified by daniel.burr
  • Distance between the HVAC DUCT and Power Socket

    As per standard what is the required space between vertical HVAC Duct & Power socket on wall. 
    last modified by lllsadiqlll
  • Looking for a code violation in attached picture.

    What is the NEC code violation, in the attached drawing. Don't need the actual answer. Just where to look in the NEC code book. Thank You 
    last modified by killerbabe79
  • panel board in pool

    per 2017 NEC can a service panel board be located in a pool equipment room with chlorine storage? this is an indoor public pool.
    last modified by paul.scott
  • hot Tube installation

    I installed an outdoor  hot tub about a week ago, the outside of the tub is plastic we poured a concrete slab with rebar since the hot tub  is made out of plastic all surroundings of the hot tub a...
    last modified by homevisionin
  • NFPA 410 - Electriicaly Grounded

    NFPA 410 section requires "To reduce the hazards associated with static electricity, aircraft shall be electrically grounded when parked in aircraft hangars."   Boeing Aircraft are statically ground...
    last modified by jeff.l.tjernagel
  • [PV inverter] regulation for wiring box

    In many cases, a wiring box is attached to a PV inverter(residental use). Generally, The wiring box has a DC circuit breaker and has an AC breaker or communication circuit as an option. I heard tha...
    last modified by hyundeok.hwang
  • Electric vehicle charging circuit

    Paperwork from the car maker suggests a NEMA 6-30 w/ #10 conductors and 30A breaker. If the car will charge for perhaps 6 hours, is there a requirement for larger size wire?  (think the need for #8 for anelectri...
    last modified by davidvartanoff
  • mounted fuel tank

    hi everybody  i hope you are all ok.... In NFPA-110 chapter 3 in the general definitions, it is mentioned that: Integral fuel tank in EPS systems: Afuel tank furnished by the EPS supplier and mounted o...
    created by alonazay
  • Busbar Design guide

    Would you tell me the design criteria for the busbar size inside the PV inverter?   As I knew, scope of NEC is external interface between parts and parts.   And, UL1741(safety standard for PV inv...
    last modified by hyundeok.hwang
  • NEC 2017 Article 706.1 Vs. 490

    A scope of "NEC 2017 Article 706.1" is ESS over 50Vac(60Vdc).   On the other hand, NEC 2017 Article 490 is a general requirements for the system over 1000V.   So, I wonder if ESS is also covered by ar...
    last modified by hyundeok.hwang
  • Standby Generator Wiring

    This is in reference to NFPA 110 Emergency and Standby Power Systems.  7.12.3 states:    If the conduit's point of attachment to the EPS in on the forcing function side of the EPS vibration isolation s...
    last modified by garrys917
  • Tamper Switches

    Which standard and paragraph shows that Tamper switches signal in 200 seconds?
    last modified by robert.schultz
  • Conductor size compared to lug size

    Scenario: There is a 4 bar electrification system for an Overhead Bridge Crane.  The runway is 900 ft long.  The company that designed the electrification system needed to use bar that is rated up to 250amp...
    last modified by dlavigne1980
  • My tool pouch was taken - what should I do?

    I need the pdf version of NEC just like I need my screwdriver and lineman's pliers at my right hip.  How do you feel about NFPA eliminating pdf version of 2020 NEC?
    last modified by chiefns830
  • Hospital Grade outlets in Nursing homes

    We are a nursing home in Florida# and follow the NFPA 70 2014 edition and CMS follows the 2011 edition.  We  have been told that a bed or piece of equipment that has hospital grade plug that it must be plugg...
    last modified by rrayburn
  • Power strips/ surge protectors

    We are a Nursing home in Florida and follow NFPA 70 2014 edition and NFPA 99 2015 edition. We have been told that we cannot use power strips for computer equipment in non resident areas. We have a power strip in a ele...
    last modified by rrayburn
  • Lightning Protection

    Is lightning protection required to be inspected every3 to 5 years?
    last modified by rrayburn