• *Electrical Safety Concerns*

    I thought that I would open up a discussion where viewers of this thread could share what they perceive to be the greatest electrical safety concern that they encounter or perhaps the most frustrating electrical safet...
    Steve Benton
    last modified by Steve Benton
  • i am going to active the deluge system with it and its inside

    i am going to active the deluge system with it and its inside  
    abrar.b
    last modified by abrar.b
  • 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
  • MCCBs PPE or Not

    I have had a question for some time about operating molded case circuit breakers with or without PPE.  NFPA 70E states in table 130.5 that under normal conditions it is a low risk of exposure to an arc flash....
    troy.wappler
    last modified by troy.wappler
  • Service Disconnect

    Been having some discussions with other people in the trade, and the subject of Service Disconnects came up in regards to OCP and it's location for dwellings or in general. Some have mentioned that the first OCP devic...
    markselectric
    last modified by markselectric
  • NEC 310.104

    For those who were helpful on this post, Thank You.   Chiefns830 managed to drive me away.   Nothing that I read indicated that homeowners were not welcome to ask electrical questions.
    maynardrf
    last modified by maynardrf
  • 480vac 3ph Power Distribution

    I have a system where we are supplying a skid with 3 VFD/motors. The VFD/motors are each wired to there own fused safety disconnect.  The skid also has a fused disconnect for power supply to a 480/120 transformer...
    marc.gelinas
    last modified by marc.gelinas
  • 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
  • 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-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
  • 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