• 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
  • 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
  • NFPA-13

    Hi, Any one tell me the NFPA allowed sprinkler system in celling.
    abrar.b
    created by abrar.b
  • City Refuses to Close Electric permit due to lack of UL certificate.

    Hello, we imported Electron-Beam Welding machine from EU to US. We invited UL inspector for the Field Inspection and received a lot of comments. While we working on UL's coments, our city's electric engineer refuses t...
    seyhun.ramazanov
    last modified by seyhun.ramazanov
  • Can 2 pole breakers supply 2 circuits

    Say for example, you have a 120/240 V, 2 pole, 20 A breaker. Does the NEC allow this breaker to serve 2 separate 120 V circuits?
    tgammonphd
    last modified by tgammonphd
  • Equipment Ground Protection

    I know NEC 250.122 takes you straight to a table that has had equipment grounds sized as long as I've been an engineer, but I recently came across a situation where I wanted to plot a conductor damage curve and a circ...
    mattotto
    last modified by mattotto
  • What PPE Category is Required in Verifying Zero Energy?

    As it pertains to NFPA 70E's requirement of placing a device, piece of equipment etc in a "Electrically Safe State", you turn off a breaker to a light switch or outlet. The next step is to verify via a meter that the ...
    carledge
    created by carledge
  • engine hall

    please advise me which detector are good for engine hall heat detector or flame detector acording to NFPA-72
    abrar.b
    last modified by abrar.b
  • NFPA-72 Help

    Please help me to design fire alarm system according to NFPA-72.I have NFPA copie.
    abrar.b
    created by abrar.b
  • Wire Color for Remain Energized 24VDC Conductors.

    NFPA79 specifies: 13.2.3.2 The use of other colors for the following applications shall be as follows: (1) WHITE with BLUE stripe for grounded (current-carrying) dc circuit conductor (2) WHITE with ORANGE stripe ...
    borisg
    last modified by borisg
  • Calculating Arc Flash PPE Tables

    Referring to NFPA 70E Table 130.7(C)(15)(A)(b) - Where is there more info, step-by-step, on how to go through the process in this table? I can't find any links and there's nothing in the annexes for this. I would hope...
    ral@livelinesafety.com
    last modified by ral@livelinesafety.com
  • 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
  • HOA hand switch leg direct to motor starter

       There has been some debate among my coworkers lately about the "Hand" switch leg of a rotary HOA selector switch going directly to the coil of a motor starter. I have been making the case that this i...
    jfosterjrod58
    last modified by jfosterjrod58
  • Rooftop sub panels

    I have a 100 amp breaker feeding a 60 amp sub panel on a rooftop. Would that sub panel need a main breaker or a disconnect?
    mtthwhenegar
    last modified by mtthwhenegar
  • What kind of relays are these, and what are their use?

    My professor asked us to check for the type of relay and why the wiring was done this way. I google it but I did not have any luck. Does anybody know?
    cgarciaphoto
    last modified by cgarciaphoto
  • Job risk assessment

     I am an electrician in a manufacturing facility.  There is a variety of electrical work that goes on here.  There is installation, troubleshooting, testing and calibrating.  I was wondering what i...
    bigwill400
    last modified by bigwill400
  • NFPA79 Article 13 - What wire color for current carrying grounded non-AC which remains energized

    NFPA 79 specifies colors for almost all situations except for non-AC current carrying grounded conductor which remain energized when the main supply circuit disconnecting means is in the off position.  By the way...
    ahudy
    last modified by ahudy
  • What Lies Ahead? NFPA 70E and Beyond

    As I look back to the beginning of 2018 and reflect on the work performed and the people that I have encountered throughout the year I would like to pause for a moment and ask myself a few questions, "Have I made a po...
    Steve Benton
    last modified by Steve Benton
  • NFPA 25/72 Inspections

    Sprinkler System inspections are generally addressed as two separate inspections. The first is the water based fire protection system that would typically be inspected by a sprinkler company and the second would ...
    devans2016
    last modified by devans2016
  • Main Circuit Breaker

    What is the proper method of sizing the main service circuit breaker? The method I use is 125% of the continuous load plus the sum of the noncontinuous loads.  [300ampX1.25] + [400amp] = 775A or 800A main. Some A...
    opes
    last modified by opes