• Installing Extra Conductors Question

    Hello,    We are building apartments in Nevada. Does the fire alarm installer have the authority to install a wire with more conductors than the plan indicate? In our case, the plans show 18-2 for smoke det...
    created by andyv
  • I have a smoke detector in a small bathroom of a building. Later, the client decided to put a false ceiling. In our drawing, it is only mentioned smoke detector. But I do need to add above ceiling smoke detector?

    The depth of the false ceiling (measured from the actual ceiling) is 900mm. Also, please mention the code number in NFPA 72 for the above issue? 
    last modified by shamilbb12
  • What Is Wrong With This Genset?

    created by david.pfau
  • Trying to determine if layering HRC-2 and HRC-4 is appropriate

    I have a recommended outfit of 20cal pants and jacket (HRC-2) with and additional long 40cal (HRC-4) overcoat. Question is would just a 40 cal HRC-4 suit be suitable or is it additive and need a 60cal suit? Additional...
    last modified by nogood911
  • Receptacle spacing - Commercial Buildings

    Is there a minimum required spacing for electrical outlets (house keeping) along high rise commercial building common corridors?  Can they be spaced further apart than the standard 12'-0" rule?
    last modified by mmonette
  • XP or not XP?

    I'm building a machine for a client that requires a 50%/50% Alcohol and Essential oils mixture to be misted on a product in a confined space (the machine enclosure). If we ventilate (extract with XP duct/fan system) t...
  • Electrical safety weekly topics

    What is the best source to get on an emailing list for weekly, plus or minus, safety topics to use in safety meetings in an electrical industry? Expecially Arc Flash topics but general electrical safety topics are nee...
  • Concession Stands / Municipal Building Fire Alarm Notification Requirements

    Good Morning,   I have an inspection today at a outdoor event that is held each year. The event has a building that is used as a concession stand. The only item that the cook in the building is grilled hot dogs....
    last modified by rstlouis
  • Conduit penetrations in Hazardous spaces

    What type of conduit sleeve is required for a conduit penetration into an unclassified space from a Hazardous Class I Division I space? How do we prevent gases from migrating around (inside and outside) the sleeve int...
    last modified by kbourassa
  • Lighting Inverter Tripping

    In testing the inverter, when the utility input is off, simulating a power outage and exterior lights come on, it quits.  All lighting is LED and by all indications the inrush is the problem.  The lighting i...
    last modified by j_w_hines
  • 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...
    last modified by dleverton
  • Is tray cable in cable tray considered exposed?

    DEFINITION: Exposed - (as applied to energized electrical conductors or circuit parts) Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to electrical conducto...
    last modified by ral@livelinesafety.com
  • Per NFPA 70E 130.2(B) Energized Work Permit if you deenergize the breaker in a bucket and the only power left is the incoming from the stabs to the top of the breaker is the work permit required?

    Also if you have multiple VFD's in one cabinet and you are changing one but the rest are powered up would a wok permit be required?
    last modified by kris.mcquiggan
  • Surge Protection

    NFPA 79, 7.8.1 States that " SPD's (surge protective device) shall be provided for industrial machinery w/ safety interlock circuits to protect against the effects of overvoltages sue to lightning and switching surges...
    last modified by jeremy.bello@emerson.com
  • Fire Protection Design of Installed PV panels

    In my country there is no regulation on installation of PV panels. My question is regarding the ones that are already installed, in this moment they don't follow NFPA 1 nither NFPA 70. How can I design a fire protecti...
    last modified by catac_16
  • 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) ...
    last modified by alan.peet
  • GFCI Below Sinks - why not?

    Anyone know why GFCIs are not required for equipment located below sinks such as in-sink waste disposers and trash compactors? I don't see a requirement in 210.8 and other sections such as 422.16(B)(1) and (2). Was cu...
    last modified by carl.mister
  • TVSS how to install

    A TVSS should be install. On the Load side or line side of the breaker.
    last modified by jrendon6861
  • that establishes nfpa -20 on the electrical supply of the controller for fire pump on the top or the lateral supply of the controller. can you clarify what the nfpa says about it

    that establishes nfpa -20 on the electrical supply of the controller for fire pump on the top or the lateral supply of the controller. can you clarify what the nfpa says about it
    last modified by mildnern