MeyerFire
  • Blog
  • Forum
  • TOOLKIT
    • ALL TOOLS
    • BUY THE TOOLKIT
  • UNIVERSITY
    • ALL COURSES
    • JOIN THE UNIVERSITY
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE PREP SERIES
    • PE 100-Day Marathon
  • LOGIN
    • TOOLKIT-ONLY LOGIN
    • UNIVERSITY LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • JOB OPENINGS
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT
Picture

Detail Level to Provide for 120V Fire Alarm Power?

12/3/2020

6 Comments

 
As a consultant, what level of detail do you go into for the line voltage (120v) fire alarm plans and wiring?

The line voltage is affected by loads / fuse sizes and affects the disconnect switch size. I'm wondering about the level of detail that an engineer should be showing versus leaving the sizing to the fire alarm and electrical contractors based on their specific system layout requirements.

​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
6 Comments
sean
12/3/2020 10:12:50 am

If I understand you properly you are wondering the level of detail of how you anticipate the electrical load of the fire alarm equipment on the building load calculations (watts).

In my office we will kick back electrical panel schedules that don't show a dedicated circuit and for a standard building (which would only use one panel and maybe a booster panel or two) a nominal standard load. If it is a larger more complicated fire alarm system where more power needs are more complex we expect that the detail go up from there.

Reply
OP
12/3/2020 11:08:27 am

Good info Sean. I think I read the question as coming more from the consulting / engineering side of things when drawings are being prepared for future bidding by others. How much information would the engineer show for fuse and wiring sizing understanding that each bidder may construct the infrastructure of their system in a different way?

Reply
sean
12/9/2020 08:55:12 pm

i hate the engineers who put out shit for fire protection engineering drawings. you know the ones where detection has no logic, and coverage for notification is insufficient, then the contractor puts together a design based on the bid spec. then i get the bad wrap of shooting them down and causing a change order.

If I was not another consultant I would be advising building owners this would be time to take advantage of the architect/engineers errors and omission policy hit them where it hurts, they will lose or learn to do it correctly, stop, or best bet hire someone.

sorry my rant, i would love to write a article on why your architect is costing you money and passing it off as the big bad AHJ.

Mark Harris
12/3/2020 03:48:15 pm

In most cases the fire alarm contractor excludes the 120 volt power wiring so it is important the the EE show the dedicated circuit on the electrical plan and panel schedule. Exception could be if the fire alarm supplier is a parts and smarts subcontractor to an electrical contractor.

At least in my markets there is usually locktab marked fire alarm that goes on the breaker. Not an expensive item but want it to be there before final inspections.

I would talk to a couple of the major fire alarm contractors in your market for their input.

Reply
Kyle MacKenzie
12/9/2020 06:51:20 pm

We have a lot line sprinkler installation with sprinkler piping being recessed in a furred out wall. We are concerned about pipe freeze ups. Since we are connected to the existing system that serves the entire floor it would not be feasible to do a dry pipe system or add anti freeze. Does anyone have a good calculation to determine if the piping will freeze in the wall cavity?

Reply
sean
12/9/2020 08:56:21 pm

i would recommend the section in the handbook/annex i believe it contains some equations to calc the thermal loss.

Reply



Leave a Reply.

    SUBMIT A QUESTION
    Picture
    Why Sponsor?

    ALL-ACCESS

    Picture
    GET ALL OUR TOOLS

    SUBSCRIBE

    Subscribe and learn something new each day:
    I'm Interested In:

    COMMUNITY

    Top April '25 Contributors
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    SEE LEADERBOARD

    YOUR POST

    SUBMIT A QUESTION

    PE EXAM

    Get 100 Days of Free Sample Questions right to you!
    SIGN ME UP!

    FILTERS

    All
    A1171
    ABA
    ADA
    ASCE 7
    ASME A17.1
    ASTM E1354
    Blog Thread
    Daily Discussion
    Design-documents
    EN 12845
    Explosion Protection
    Explosion-protection-prevention
    Fire Detection And Alarm Systems
    Fire Dynamics
    Flammable And Combustible Liquids
    Flammable-combustible-liquids
    FM Global
    Human-behavior
    IBC
    ICC 500
    IEBC
    IFC
    IMC
    IPC
    IRC
    ISO
    Means Of Egress
    NBC
    NFPA 1
    NFPA 10
    NFPA 101
    NFPA 11
    NFPA 110
    NFPA 1142
    NFPA 1221
    NFPA 13
    NFPA 13D
    NFPA 13R
    NFPA 14
    NFPA 15
    NFPA 16
    NFPA 17A
    NFPA 20
    NFPA 2001
    NFPA 214
    NFPA 22
    NFPA 220
    NFPA 24
    NFPA 241
    NFPA 25
    NFPA 291
    NFPA 30
    NFPA 307
    NFPA 30B
    NFPA 31
    NFPA 33
    NFPA 37
    NFPA 400
    NFPA 409
    NFPA 415
    NFPA 45
    NFPA 495
    NFPA 497
    NFPA 5000
    NFPA 502
    NFPA 54
    NFPA 55
    NFPA 654
    NFPA 68
    NFPA 70
    NFPA 701
    NFPA 72
    NFPA 75
    NFPA 770
    NFPA 82
    NFPA 855
    NFPA 90A
    NFPA 92
    NFPA 96
    NICET
    OBC
    OSHA
    Passive Building Systems
    PE Prep Guide
    PE Prep Series
    PE Sample Problems
    Poll
    Smoke Management
    Special Hazard Systems
    UFC 3-600-01
    UFC 4-021-01
    UFC 4-211-01
    UPC
    Updates
    Water Based Fire Suppression
    Weekly Exams


    ARCHIVES

    May 2025
    April 2025
    March 2025
    February 2025
    January 2025
    December 2024
    November 2024
    October 2024
    September 2024
    August 2024
    July 2024
    June 2024
    May 2024
    April 2024
    March 2024
    February 2024
    January 2024
    December 2023
    November 2023
    October 2023
    September 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    March 2023
    February 2023
    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    November 2016
    October 2016
    July 2016
    June 2016


    PE PREP SERIES

    SEE LEADERBOARD

    RSS Feed

Picture
​Home
Our Cause
The Blog
The Forum
PE Exam Prep
The Toolkit

MeyerFire University
​Pricing
Login
​Support
Contact Us
Picture

MeyerFire.com is a startup community built to help fire protection professionals shine.
Our goal is to improve fire protection practices worldwide. We promote the industry by creating helpful tools and resources, and by bringing together industry professionals to share their expertise.

​MeyerFire, LLC is a NICET Recognized Training Provider and International Code Council Preferred Education Provider.

All text, images, and media ​Copyright © 2016-2025 MeyerFire, LLC

We respect your privacy and personal data. See our Privacy Policy and Terms of Service. 
The views, opinions, and information found on this site represent solely the author and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence.

Discussions are solely for the purpose of peer review and the exchange of ideas. All comments are reviewed. Comments which do not contribute, are not relevant, are spam, or are disrespectful in nature may be removed. Information presented and opinions expressed should not be relied upon as a replacement for consulting services. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a small commission for orders placed elsewhere.

  • Blog
  • Forum
  • TOOLKIT
    • ALL TOOLS
    • BUY THE TOOLKIT
  • UNIVERSITY
    • ALL COURSES
    • JOIN THE UNIVERSITY
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE PREP SERIES
    • PE 100-Day Marathon
  • LOGIN
    • TOOLKIT-ONLY LOGIN
    • UNIVERSITY LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • JOB OPENINGS
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT