Fire Alarm Submittal Guides
NFPA 72 battery calcs, voltage drop, and AHJ submittal packages, based on 47 real approved permit jobs.
August 10, 2026 · 6 min read
Billing for Alarm Work: What to Invoice and WhenA fire alarm contractor's guide to progress billing, T&M service calls, recurring contracts, and retainage, so invoices actually get paid on time.
August 3, 2026 · 6 min read
Common Fire Alarm Plan Review Comments (and How to Answer Them)The plan review comments that keep coming back on fire alarm submittals, what each one actually means, and the fastest clean way to answer it.
July 28, 2026 · 6 min read
NFPA 72 Secondary Power: The 24-Hour Standby Rule ExplainedWhy NFPA 72 wants 24 hours of standby plus 5 minutes of alarm (15 for voice), how that feeds the battery calc, and when a generator fits instead.
July 24, 2026 · 4 min read
Deficiency or Impairment? NFPA 25's Three Tiers and the Chapter 15 ProcedureWhat separates a noncritical deficiency from a critical one from a full impairment under NFPA 25 — and the exact Chapter 15 steps required when a sprinkler system comes out of service.
July 24, 2026 · 4 min read
Quarterly Sprinkler System Inspections: NFPA 25 ScheduleWhat NFPA 25 requires for sprinkler system inspections: quarterly visits, the annual check, and the 3-year and 5-year internal and standpipe tests.
July 23, 2026 · 6 min read
NFPA 10 Fire Extinguisher Inspection & Maintenance Schedule, ExplainedThe full NFPA 10 service schedule in one place: monthly inspections, annual maintenance, the 6-year internal exam, and hydrostatic testing at 5 or 12 years depending on the agent type.
July 23, 2026 · 4 min read
What NFPA 10 Actually Requires on a Fire Extinguisher Service TagThe service tag, the verification-of-service collar, the 6-year internal label, and the hydro test label — what each record must say under NFPA 10, and which service gets which.
July 23, 2026 · 4 min read
Fire Extinguisher Hydrostatic (Pressure) Test: 5 YearsFire extinguisher pressure (hydrostatic) testing: which agents hydro at 5 years vs 12, your test date and validity, and how it meets NFPA 10's 6-year exam.
July 20, 2026 · 5 min read
Fire Alarm Riser Diagrams: What Plan Reviewers Look ForWhat actually belongs on a fire alarm riser diagram, and why reviewers check it against your battery calc and device matrix before anything else.
July 13, 2026 · 6 min read
Building a Fire Alarm Device Matrix (With a Real Example)A walkthrough of a real device matrix: addresses, circuits, currents, and the annunciation and supervision columns a plan reviewer actually checks.
July 8, 2026 · 5 min read
Fire Alarm Cut Sheets: What AHJs Actually Want to SeeCut sheets sink more submittals than bad calcs do. Here's what AHJs actually want highlighted on the sheet, and the one mistake that gets it kicked back.
June 29, 2026 · 5 min read
Battery Calc Differences: Potter vs Fire-Lite vs Silent KnightHow Potter, Fire-Lite, and Silent Knight structure battery worksheets differently: where to find the numbers and how each handles the derating factor.
June 28, 2026 · 5 min read
Why AHJs Reject Fire Alarm Submittals (Top Reasons)Most AHJ rejections trace back to six fixable mistakes. Here's what's missing from your submittal package and how to fix each one fast.
June 26, 2026 · 5 min read
Sizing a NAC Circuit: Current Limits and Voltage DropHow to add up horn/strobe current draw, apply NAC de-rating, and know when voltage drop forces a circuit split or booster.
June 25, 2026 · 5 min read
Duct Smoke Detector Requirements Without the GuessworkCFM thresholds, sampling tube sizing, remote station placement, and the IMC vs NFPA 72 overlap that catches fire alarm techs off guard.
June 24, 2026 · 4 min read
Class A vs Class B Fire Alarm Wiring: When and WhyUnderstand the survivability difference between Class A and Class B fire alarm wiring, where AHJs actually require Class A, and the real cost tradeoff.
June 23, 2026 · 5 min read
Fire Alarm Candela and Strobe Spacing, ExplainedHow to read the NFPA 72 candela tables for wall and ceiling strobes, pick the right cd rating for a real room, and avoid the sync gotcha.
June 21, 2026 · 8 min read
NFPA 72 Battery Calculation: A Step-by-Step Walkthrough for Working ContractorsWalk through the 24-hour standby and 5-minute alarm battery calc from NFPA 72 using real numbers from a Potter panel swap, including the 1.2x derating factor.
June 21, 2026 · 8 min read
Fire Alarm Voltage Drop Calculation: The Real Numbers (and Why Most Submittals Show Zero)How the fire alarm voltage drop calc actually works, why the panel maker's form almost always shows zero, and when you really need real wire-run numbers.
June 21, 2026 · 10 min read
What Goes in a Fire Alarm AHJ Submittal Package? (Based on 47 Real Approved Jobs)A practical checklist of every component in approved fire alarm permit packages, with notes on which AHJs want each one, from 47 real completed jobs.