Fire Alarm Reference Charts
Strobe candela, detector spacing, and device-placement look-up tables for NFPA 72 layout.
Electrical
26 CHARTSConductor, conduit, and grounding look-up charts for sizing and code checks.
CONDUCTORS & AMPACITY
- AMPWire Ampacity ChartCu & Al ampacity at 60 / 75 / 90°C by size.NEC 310.16
- ×0.8Ampacity Correction & Adjustment FactorsAmbient & bundling derate multipliers.NEC 310.15(B)(1) & 310.15(C)(1)
- DIMWire Dimensions ChartDiameter & area by insulation type and size.NEC Chapter 9, Table 5
- Ω/kftWire Resistance ChartDC resistance & stranding by AWG / kcmil.NEC Chapter 9, Table 8
CONDUIT, RACEWAY & TRAY
- FILLConduit Size & Fill ChartUsable fill area by trade size, EMT to PVC.NEC Chapter 9, Tables 1 & 4
- LBConduit Bodies ChartLB, LL, LR, T & X decoded, with form profiles.NEC 314.16(C)
- CTFCable Tray Fill ChartAllowable tray fill by width, ladder & solid.NEC 392.22
- MAXTHHN Conduit Wire Capacity ChartMax THHN counts per conduit type and size.NEC Annex C
GROUNDING & BONDING
- GNDGround Wire Size ChartMinimum EGC size by breaker or fuse rating.NEC 250.122
- GECGrounding Electrode Conductor ChartGEC size from the service-entrance conductor.NEC 250.66
- MBJBonding Jumper Size ChartMBJ / SSBJ & grounded conductor by supply size.NEC 250.102(C)(1)
- TRAYCable Tray Grounding ChartTray metal area to serve as the EGC, by OCPD.NEC 392.60(A)
MOTORS & TRANSFORMERS
MOTOR CIRCUITS & STARTERS
- SZ 1NEMA Starter Size ChartSizes 00–9: max HP per voltage, plus amps.NEMA ICS 2
- 175%Motor Circuit Protection ChartMax fuse & breaker % of FLA, plus overloads.NEC 430.52 / 430.32
- MTRMotor Circuit Data ChartWire, fuse, breaker, starter & switch per HP.NEC 430 / NEMA ICS 2
- AC-3IEC vs NEMA Starter ChartAC-1–AC-4 duties and the NEMA trade-offs.IEC 60947-4-1
DISCONNECTS & FUSES
ENCLOSURES & RECEPTACLES
Plumbing
20 CHARTSFixture units, drainage sizing, and pipe look-up tables — IPC and UPC labeled.
DRAINAGE, WASTE & VENT
- DFUDrainage Fixture Unit (DFU) ChartDFU values per fixture, IPC & UPC side by side.IPC 709.1 / UPC 702.1
- DRNDrain Pipe Size ChartDrain & building-drain size from total DFU.IPC 710.1 / UPC 703.2
- BLDGBuilding Drain & Sewer Capacity ChartMax DFU on building drain & sewer, by slope.IPC 710.1(1) / UPC 703.2
- VENTVent Pipe Size ChartVent size from DFU and developed length.IPC 906.1 / UPC 703.2
- SLPDrain Pipe Slope ChartMinimum grade per pipe size, IPC & UPC.IPC 704.1 / UPC 708.1
- TRAPFixture Trap Size ChartMin trap & trap-arm size per fixture, IPC & UPC.IPC 709.1 / UPC 702.1
WATER SUPPLY SIZING
- WSFUWater Supply Fixture Unit (WSFU) ChartWSFU per fixture, with GPM demand conversion.IPC E103.3 / UPC 610
- GPMWSFU to GPM Conversion ChartDesign GPM from total WSFU, both system types.IPC E103.3(3)
- WTRWater Pipe Sizing ChartSupply pipe & meter size from WSFU and length.UPC 610.4 / IPC 604.3
- FLOWFixture Water Demand ChartMax GPM & GPF per fixture, code & WaterSense.IPC 604.4 / EPAct 1992
FUEL GAS PIPING
- GASNatural Gas Pipe Sizing ChartPipe size from BTU load and longest run.NFPA 54 / IFGC 402
- CSSTCSST Gas Sizing ChartNatural gas CSST capacity by EHD & length.NFPA 54 / manufacturer
- LPLP / Propane Pipe Sizing ChartPropane pipe capacity by size & length.NFPA 58 / NFPA 54
- BTUGas Appliance BTU Demand ChartTypical gas appliance input BTU/hr.Manufacturer / code
STORM & GREASE
SPECIALTY PIPING
- AIRCompressed Air Pipe Sizing ChartCompressed air pipe SCFM by size.Engineering
- MEDMedical Gas ReferenceMedical gas systems, colors & sizing.NFPA 99
- RECIRCHot Water Return Sizing ChartRecirculation return line sizing.Engineering
- PDIWater Hammer Arrestor ChartPDI arrestor size A–F by fixture units.PDI-WH201
HVAC & Mechanical
34 CHARTSDuct sizing, airflow, static pressure, and sheet-metal look-up tables.
DUCT SIZING & AIRFLOW
- CFMDuct Sizing ChartCFM per round duct size at design friction rates.ASHRAE Fundamentals
- DeRectangular to Round Duct Conversion ChartEqual-friction rect ↔ round duct equivalents.ASHRAE Fundamentals
- ΔPDuct Friction Loss ChartLoss per 100 ft by CFM and duct diameter.Darcy-Weisbach (computed)
- FLEXFlex Duct CFM ChartTaut flex vs rigid CFM, plus the slack penalty.LBNL / ADC / UL 181
- FPMAir Velocity ChartRecommended FPM for ducts, grilles & coils.ASHRAE / ACCA lineage
LOAD & SYSTEM RULES
SHEET METAL & CONSTRUCTION
REFRIGERANT P-T CHARTS
- R410AR-410A Pressure-Temperature ChartR-410A saturation pressure by temperature.Refrigerant property data
- R454BR-454B Pressure-Temperature ChartR-454B P-T, the A2L R-410A replacement.Refrigerant property data
- R32R-32 Pressure-Temperature ChartR-32 saturation pressure by temperature.Refrigerant property data
- R22R-22 Pressure-Temperature ChartR-22 P-T for legacy system service.Refrigerant property data
REFRIGERANT SERVICE & DESIGN
- SH/SCSuperheat & Subcooling ReferenceSuperheat & subcooling targets and method.Manufacturer / field
- LINERefrigerant Line Sizing ChartSuction & liquid line size by tonnage.Manufacturer / ASHRAE
- A2LRefrigerant Comparison ChartR-22 / 410A / 454B / 32: class, GWP, glide.ASHRAE 34
- TXVMetering Device & TXV ReferenceMetering device types & TXV sizing.Manufacturer
EQUIPMENT REFERENCE
LOAD & CONVERSIONS
PSYCHROMETRICS & HEAT
VENTILATION & COMBUSTION AIR
- CFM/PVentilation Rate ChartOutdoor air CFM/person & /sqft, 62.1.ASHRAE 62.1
- ACHAir Changes Per Hour ChartAir changes per hour by space type.ASHRAE / mech. code
- FPMDiffuser & Grille Sizing ChartDiffuser & grille face velocity, CFM.Manufacturer / ASHRAE
- ECONEconomizer & Outside Air ReferenceEconomizer & OA damper requirements.ASHRAE 90.1
- COMBCombustion Air Sizing ChartCombustion air volume & opening sizing.IMC / NFPA 54
UNIT CONVERSIONS
- kWBTU / Watts / kW Conversion ChartBTU/h ↔ kW ↔ watts ↔ tons, tabulated.Computed (NIST SP 811)
- °F°CTemperature Conversion Chart°F ↔ °C, −40 to 250, design points marked.Computed (exact)
- in.wcPressure Conversion Chartin.wc, psi, Pa, kPa & bar, both directions.Computed (ISO 80000-4)
- L/sAirflow Conversion ChartCFM ↔ L/s ↔ m³/h at common airflows.Computed (exact)
Fire Alarm
30 CHARTSStrobe candela, detector spacing, and device-placement look-up tables for NFPA 72 layout.
NOTIFICATION APPLIANCES
- cdStrobe Candela ChartWall-mount strobe candela by room size.NFPA 72 Table 18.5.5.7.1(a)
- ◎cdCeiling Strobe Candela ChartCeiling strobe candela by room & height.NFPA 72 Table 18.5.5.7.1(b)
- ‖‖Corridor Strobe Spacing Chart15 cd corridor spacing & placement.NFPA 72 18.5.5.8
- dBAAudible dBA Requirements ChartPublic / private levels & ambient dBA.NFPA 72 18.4
DETECTION LAYOUT & SPACING
- SDSmoke Detector Spacing Chart30 ft spacing & the 0.7 point rule.NFPA 72 17.7.4.2.3.1
- HDHeat Detector Spacing ChartSpacing reduction by ceiling height.NFPA 72 Table 17.6.3.5.1
- ±3′Detector Placement RulesWalls, HVAC, beams & sloped ceilings.NFPA 72 17.7.4
- °FHeat Detector Temperature ChartTemp classes, ranges & color codes.NFPA 72 Table 17.6.2.1
MOUNTING & MANUAL STATIONS
POWER & BATTERIES
NAC CIRCUITS & WIRING
- VdNAC Voltage Drop ChartEnd-of-line voltage by gauge & run length.Computed · 24 VDC
- AWGFire Alarm Wire Size ChartMax NAC run length by gauge & load.Computed · 24 VDC
- mANAC Current Draw ChartTypical horn/strobe current by candela.Manufacturer typical
- EOLEnd-of-Line Resistor ChartTypical end-of-line resistor by panel.Manufacturer typical
CABLE & PATHWAYS
- FPLPFire Alarm Cable TypesFPL, FPLR, FPLP & CI cable decoded.NEC 760.176 & 760.179
- SUBCable Substitution HierarchyWhich cables may replace which.NEC Table 760.154
- A/XPathway Class ChartPathway Class A, B, C, D, E, N & X.NFPA 72 12.3
- PLPower-Limited vs Non-Power-LimitedPower-limited vs non-power-limited.NEC 760 Parts II & III
SYSTEM INTERFACES
- DUCTDuct Smoke Detector RequirementsDuct smoke detectors by CFM & action.IMC 606 / NFPA 90A
- ELEVElevator Recall & Shunt TripPhase 1 recall & shunt-trip triggers.NFPA 72 21.3 / ASME A17.1
- FLOWSprinkler Monitoring ReferenceWaterflow & tamper: alarm vs supervisory.NFPA 72 17.12–17.14
- HOLDDoor Holder & Damper InterfaceDoor holders & fire/smoke dampers.NFPA 72 / 80 / 90A
- SMKSmoke Control InterfaceSmoke control & firefighter override.NFPA 92 / IBC 909
VOICE EVACUATION
Telecom & Data
40 CHARTSPinouts, cable categories, PoE power, and pathway look-up tables for structured cabling.
PINOUTS & TERMINATION
- RJ45T568A vs T568B WiringBoth RJ45 pinouts, pin by pin.ANSI/TIA-568
- 8P8CRJ Connector PinoutsRJ11 to RJ45 — positions, contacts, lines.USOC / TIA-568
- 66/11066 & 110 Block Reference66 vs 110 blocks — rows, clips & use.USOC / TIA-568
- W-BL25-Pair Color CodeAll 25 pairs, tip and ring, in order.ICEA / Bell convention
CABLE CATEGORIES & DISTANCE
CODE, RATINGS & PATHWAYS
FIBER IDENTIFICATION & CONNECTORS
- 12FFiber Optic Color CodeThe 12-color sequence, tubes & jackets.TIA-598
- LCFiber Connector TypesLC to MPO — ferrules, latches & colors.TIA-568.3 / convention
- 9/50Multimode vs Singlemode FiberCore, source, reach & cost, side by side.comparison
- A·B·CMPO Polarity MethodsMethods A, B & C — cords, keys & pins.TIA-568.3-D
FIBER DISTANCE & WAVELENGTHS
FIBER LOSS & TESTING
PATHWAYS & INSTALLATION
- TRAYData Cable Tray FillComms tray fill & depth by tray size.TIA-569 practice / NEC 392
- 4×ODBend Radius & Pulling TensionBend radius & max pull by cable type.TIA-568 / mfr specs
- ⚡60WPoE Bundle AmpacityBundled PoE amps by AWG & bundle size.NEC 725.144
- 24″OSP Burial Depths & SeparationsComms burial depths & power separation.NEC Ch.8 / RUS practice
ROOMS, RACKS & GROUNDING
DESIGN & ADMINISTRATION
SECURITY & ACCESS CONTROL
COAX & RF DISTRIBUTION
AV & SOUND
Excavation & Sitework
20 CHARTSTrench safety, soil classification, and OSHA protective-system look-up tables for sitework.
SLOPING, BENCHING & SOIL
PROTECTIVE SYSTEMS
- 5ftTrench Protective SystemsThe 5 ft rule & the four design options.OSHA 1926.652
- SHORTrench Shoring ReferenceTimber & hydraulic shoring frameworks.OSHA 1926 Subpart P App C/D
- BOXTrench Box & Shield RulesThe 2 ft rule, ratings & combo setups.OSHA 1926.652(g)
- >20′Deep Excavation RulesThe 20 ft line & when a PE must design.OSHA 1926.652
SITE SAFETY & UTILITIES
EARTHWORK VOLUMES & MATERIALS
- +25%Swell & Shrink Factor ChartSwell & shrink ranges by material.geotech-typical ranges
- lb/CYMaterial Weight ChartLbs per CY, bank & loose, in ranges.published ranges
- B→L→CEarthwork Volume ConversionsBCY / LCY / CCY with worked math.computed
- ÷27Cubic Yard CalculationsL×W×D÷27 and the section methods.computed
- C/FCut & Fill ReferenceBalance math — where swell & shrink bite.practice
HAULING, LOADING & SOIL HANDLING
- 14CYDump Truck Capacity ChartCY & payload by truck — weight governs.practice / DOT limits
- 90%Bucket Capacity & Fill FactorsHeaped ratings & fill factors by material.SAE / mfr-typical
- 6″Topsoil Stripping ReferenceStrip depths, stockpiles & respread.practice
- FILLFill Material TypesStructural to unsuitable, decoded.spec practice
- OMCSoil Moisture ReferenceOMC, the ±2% window & field fixes.geotech practice
ABOUT THESE CHARTS
These charts cover the numbers fire alarm contractors and low-voltage installers look up while laying out a system: minimum strobe candela by room size for wall and ceiling mounting, the corridor allowance, smooth-ceiling smoke detector spacing and the 0.7 rule, the heat detector ceiling-height reduction factors, the heat detector temperature classes and their color codes, public and sleeping-area audibility levels, device mounting heights, and manual pull station placement.
Fire alarm is the most edition-sensitive trade we cover: NFPA 72 re-issues every three years and jurisdictions enforce editions from 2013 to 2025 side by side, with values and even table numbers changing between them. Every chart states the edition it reflects (the 2022 edition unless noted) and flags known deltas. These are working references for licensed installers and designers, not a substitute for the code book, the equipment listing, or the authority having jurisdiction — who has the final say on candela layouts, monitoring, and coverage.
Beyond the layout look-ups, the charts also cover the circuit side of the trade: standby battery sizing, notification-circuit voltage drop and wire length, typical appliance current draw, end-of-line resistors, the NEC Article 760 cable types and their substitution hierarchy, and the NFPA 72 pathway classes. Computed charts state their basis; manufacturer-specific values (current draws, resistor values) are labeled typical and sent back to the data sheet.
The interface charts cover how the fire alarm system drives the rest of the building: duct smoke detectors and air-handler shutdown, elevator Phase 1 recall and shunt trip, sprinkler waterflow and tamper monitoring, magnetic door holders and fire/smoke dampers, and smoke control. Voice evacuation adds speaker tap levels and the intelligibility (STI/CIS) targets, and the detection set is rounded out with carbon monoxide placement, projected beam detectors for high ceilings, and the pathway survivability levels.