• 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...
    garrys917
    last modified by garrys917
  • Line side/Load side versus Bus side/Line side

    Does anyone know the history and where (if one exists) for the official definition of "Line Side" and "Load Side"?   Countless standards such as the NFPA 70 (NEC), 70E, IEEE 1584, C37.20.2, and even electric equ...
    george.cole
    last modified by george.cole
  • VFD Input/Output Current

    If my VFD outputs more current than my motor, but is the right HP, do I size my MCP for the drive, or for the motor?
    ademko
    last modified by ademko
  • Photovoltaic - 2017 NEC 705.12(B)(2)(3)(a) and 705.12(B)(2)(3)(b)

    The way I’m interpreting this section, the Photovoltaic installation must comply with either 705.12(D)(2)(3)(a) OR 705.12(D)(2)(3)(b):   (a) says that 125% of the inverter output circuit current (can be obt...
    chiefns830
    last modified by chiefns830
  • NFPA 72 Dedicated Function Fire Alarm

    Using ICC 2012 and NFPA 72 2010 edition,  Given an occupancy that is not required to have a fire alarm by 907.2.4 and is sprinklered per 903.2.4 thus contains a dedicated function fire alarm unit for water flow ...
    blalkire
    last modified by blalkire
  • Single motor protection with VFD per Article 430.130

    Looking for interpretation of Article 430.130(A)(1) and (2) with respect to Branch-Circuit Short-Circuit and Ground Fault Protective device rating for single motor applications when a VFD is installed. The article ref...
    tom.brenner
    last modified by tom.brenner
  • NFPA 410 - Electriicaly Grounded

    NFPA 410 section 7.4.3.1 requires "To reduce the hazards associated with static electricity, aircraft shall be electrically grounded when parked in aircraft hangars."   Boeing Aircraft are statically ground...
    jeff.l.tjernagel
    last modified by jeff.l.tjernagel
  • Elevator Recall

    Does Fire Sprinkler riser's water flow switch initiate elevator emergency recall? In NFPA 72 "Table A.14.6.2.4" Typical Input/Output Matrix" shows water flow switch on first or second floor initiate elevator emer...
    zara.mosavat
    last modified by zara.mosavat
  • 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...
    jeffrey
    last modified by jeffrey
  • Cell Dialers / Radios

    I am trying to locate any requirements of NFPA 72 on the installation location of cellular dialer/radios.  Are they required to be in the same room as the fire alarm panel?  Thanks
    brandonhigley
    last modified by brandonhigley
  • Distance between the HVAC DUCT and Power Socket

    As per standard what is the required space between vertical HVAC Duct & Power socket on wall. 
    lllsadiqlll
    last modified by lllsadiqlll
  • 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.
    paul.scott
    last modified by paul.scott
  • 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...
    antman33
    last modified 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...
    daniel.burr
    last modified by daniel.burr
  • 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 
    killerbabe79
    last modified by killerbabe79
  • 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...
    homevisionin
    last modified by homevisionin
  • [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...
    hyundeok.hwang
    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...
    davidvartanoff
    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: 3.3.7.3 Integral fuel tank in EPS systems: Afuel tank furnished by the EPS supplier and mounted o...
    alonazay
    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...
    hyundeok.hwang
    last modified by hyundeok.hwang