NEC 2026 Article 760: Fire Alarm Systems – What Changed and What Stayed

Article 760 remains the primary NEC reference for fire alarm system installation. But in NEC 2026, it doesn't stand alone—general requirements moved to new articles while system-specific rules stay in 760. Here's what fire alarm contractors need to know.

Article 760's New Role in NEC 2026

In previous NEC editions, Article 760 was largely self-contained. Fire alarm contractors could work primarily from this single article, with occasional references to other sections. NEC 2026 changes this approach.

Article 760 remains the fire alarm contractor's primary reference for system-specific requirements. However, general requirements that applied to all limited-energy systems—including fire alarm—have moved to dedicated articles:

Requirement Type	Previous Location	NEC 2026 Location
General wiring methods	760.130+	Article 720 (with 760 references)
Power source requirements	760.41, 760.121	Article 721 (referenced from 760)
Cable types and marking	760.154, 760.176, 760.179	Article 722 (consolidated)
Raceway requirements	Throughout 760	Article 723
Grounding and bonding	760 provisions	Article 750
Fire alarm-specific rules	Article 760	Article 760 (retained)

This reorganization means fire alarm contractors now work from multiple coordinated articles rather than one comprehensive article. The benefit is consistency—the same general requirements apply to all limited-energy systems, eliminating subtle differences between articles.

What Remains in Article 760

Article 760 retains requirements that are unique to fire alarm systems:

Scope and Circuit Classifications

Article 760 continues to define the two fundamental fire alarm circuit types:

Circuit Type	Abbreviation	Characteristics
Non-Power-Limited Fire Alarm	NPLFA	Up to 600V, unlimited power output, Chapter 3 wiring methods required
Power-Limited Fire Alarm	PLFA	Voltage and power limited per Chapter 9 Tables 12(A) and 12(B), relaxed wiring methods

Most modern fire alarm systems use PLFA circuits. The power limitation (maximum 100VA nameplate rating) makes these circuits inherently safer, allowing the use of smaller conductors and simpler wiring methods.

Fire Alarm Power Supply Requirements

Article 760 maintains specific requirements for fire alarm power supplies:

• Dedicated branch circuit - Fire alarm equipment requires its own circuit with no other loads
• No GFCI or AFCI protection - These protective devices could cause nuisance tripping and compromise life safety
• Red-identified overcurrent device - The breaker must be red or marked "FIRE ALARM CIRCUIT"
• Accessible only to qualified personnel - The disconnecting means must not be readily accessible to unauthorized persons

Fire Alarm-Specific Wiring Rules

While general wiring methods reference Article 720, Article 760 retains rules specific to fire alarm installations:

• Fire alarm cables penetrating fire barriers require fire caulking
• Support requirements within occupied spaces (every 18 inches within 7 feet of floor)
• Prohibition against strapping cables to raceway exteriors
• Requirements for metallic protection in accessible areas

Separation From Other Circuits

Article 760 continues to address separation between fire alarm and other circuit types:

Circuit Combination	Requirement
PLFA with Class 1/Power	Cannot share enclosures/raceways without barriers; ¼" minimum separation if in same enclosure for equipment connection
PLFA with Class 2/3	Permitted in same cable, tray, or raceway; Class 2/3 insulation must meet PLFA requirements
PLFA with audio systems	Cannot share same raceway or enclosure (exception for specific applications)
PLFA parallel to power	2-inch minimum separation unless power is in raceway or metal-sheathed cable

Fire Alarm Cable Types Under NEC 2026

Fire alarm cable requirements now appear in Article 722, the consolidated cable article. However, the familiar cable designations remain:

Power-Limited Fire Alarm Cables

Type	Name	Application	Testing Standard
FPLP	Power-Limited Fire Alarm, Plenum	Ducts, plenums, air-handling spaces	UL 1424 + UL 910 (plenum tunnel)
FPLR	Power-Limited Fire Alarm, Riser	Vertical runs, floor-to-floor, shafts	UL 1424 + UL 1666 (vertical riser)
FPL	Power-Limited Fire Alarm	General purpose, horizontal runs	UL 1424 + UL 1581 (vertical flame)

FPLP vs. FPLR Selection

Choosing between plenum and riser cable depends on the installation environment:

Use FPLP when:

• Installing in air-handling spaces (above drop ceilings used for return air)
• Running through HVAC plenums or ducts
• Required by local code or fire marshal

Use FPLR when:

• Running vertically between floors
• Installing in elevator shafts
• Penetrating fire-rated floor assemblies

Use FPL when:

• Running horizontally within a single floor
• Installing in non-plenum ceiling spaces
• One- and two-family dwellings (per NEC allowance)

Cable Substitution Hierarchy

Article 722 (and previously 760.154) permits cable substitutions following this hierarchy—higher-rated cables can always substitute for lower-rated:

• FPLP → Can substitute for FPLR, FPL, and CM types
• FPLR → Can substitute for FPL and CM types
• FPL → Can substitute for CM, CMG types

You can always use plenum-rated cable everywhere. The reverse is not true—riser cable cannot be used in plenum spaces, and general-purpose cable cannot be used in riser applications.

Cable Specifications

Fire alarm cables must meet these baseline requirements (now in Article 722):

• Voltage rating: Minimum 300V
• Temperature rating: Minimum 60°C (140°F)
• Conductor material: Copper (solid or stranded)
• Conductor size: Minimum 18 AWG for single conductors; 26 AWG permitted only for multiconductor cables with proper splicing equipment

Coordination with NFPA 72

NEC Article 760 and NFPA 72 (National Fire Alarm and Signaling Code) work together. The NEC governs wiring and installation; NFPA 72 governs system design, device placement, and functionality:

Aspect	Governing Code
Wire and cable installation	NEC Article 760
Detector spacing and placement	NFPA 72
Circuit wiring methods	NEC Article 760
Notification appliance coverage	NFPA 72
Power supply requirements	NEC Article 760 + NFPA 72
System testing and inspection	NFPA 72
Grounding and bonding	NEC Article 750 (2026)

NFPA 72 Section 12.2.3 explicitly requires fire alarm wiring and equipment to comply with NEC Article 760. Both codes must be followed for compliant installations.

The New Inspection Framework

Under NEC 2026, electrical inspectors approach fire alarm systems with a multi-article framework:

1. Article 720 - Verify general wiring method compliance
2. Article 722 - Check cable types, listing, and marking
3. Article 750 - Verify grounding and bonding
4. Article 760 - Check fire alarm-specific requirements
5. NFPA 72 - Verify system design and functionality (typically by fire marshal)

This systematic approach replaces the previous method where inspectors might reference only Article 760. The benefit is consistency—fire alarm installations now receive the same general requirements verification as other limited-energy systems.

Practical Installation Guidance

Branch Circuit Requirements

Fire alarm control panels require a dedicated branch circuit with specific characteristics:

• No other equipment on the circuit
• Overcurrent protection sized per panel requirements
• Red handle tie or red breaker identification
• Directory marking as "FIRE ALARM"
• Disconnecting means accessible only to qualified personnel (typically in locked electrical room)

Conductor Support

PLFA cables require support at specific intervals:

• Maximum 4.5 feet (1.4m) for cables not in raceway
• Within 12 inches of junction boxes and terminations
• Every 18 inches when within 7 feet of floor in accessible areas

Fire Barrier Penetrations

Where fire alarm cables penetrate fire-rated assemblies:

• Firestop material required at all penetrations
• Listed firestop systems for rated assemblies
• Documentation of firestop installations
• Metal raceway or rigid nonmetallic conduit required up to 7 feet in accessible areas

Conductor Sizing

Minimum conductor sizes for PLFA circuits:

• Single conductors: 18 AWG minimum
• Multiconductor cables: 26 AWG permitted when properly spliced and terminated on compatible equipment
• Voltage drop considerations: Size conductors to maintain proper voltage at devices (per manufacturer specifications and NFPA 72)

Common Inspection Issues

Based on typical fire alarm inspection findings, watch for:

1. Missing fire caulking - All fire barrier penetrations must be firestopped
2. Improper cable support - Particularly in accessible areas requiring 18-inch intervals
3. Wrong cable type - Using FPL in plenum spaces or FPLR in plenums
4. Shared circuits - Fire alarm panel on circuits with other loads
5. Missing circuit identification - Breaker not red or not marked
6. Separation violations - PLFA cables sharing enclosures with power without proper barriers
7. Grounding issues - Panel not properly bonded per Article 750

Navigating Between Articles

Here's a practical workflow for NEC 2026 fire alarm compliance:

Question	Check This Article
What wiring methods are acceptable?	Article 720, then Article 760
What power source qualifies as PLFA?	Article 721 (power sources)
What cable type do I need?	Article 722 (cables)
Can I substitute cable types?	Article 722 substitution table
What raceway can I use?	Article 723 (raceways/trays)
How do I ground the system?	Article 750 (grounding)
What are fire alarm-specific rules?	Article 760
What about detector spacing?	NFPA 72 (not NEC)

Pro Tips for Fire Alarm Contractors

1. Tab your 2026 NEC. Mark Articles 720, 721, 722, 750, and 760. You'll reference all of them for complete fire alarm compliance.
2. Keep both codes handy. NEC for wiring, NFPA 72 for system design. Inspectors may reference either or both.
3. Document everything. Photograph firestop installations, cable labels, and overcurrent device identification. Provide documentation packets for inspection.
4. Use plenum cable liberally. FPLP works everywhere. When in doubt, the extra cost of plenum-rated cable prevents callbacks and inspection failures.
5. Verify AHJ requirements. Some jurisdictions have local amendments or additional requirements beyond NEC and NFPA 72. Check with the Authority Having Jurisdiction before installation.
6. Separate fire alarm clearly. Maintain required separation from power and clearly identify fire alarm circuits in panels and junction boxes.

Related NEC 2026 Content

• NEC 2026 Article 720: General Requirements for Limited-Energy Systems
• NEC 2026 Articles 721-723: Class 2 and Class 3 Circuits Complete Guide
• NEC 2026 Article 750: Grounding and Bonding
• How NEC 2026 Affects Fire Alarm, Security, and Access Control Contractors
• NEC 2023 vs NEC 2026: What Changed for Low Voltage Contractors

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Last updated: February 2026. This article provides general guidance on NEC 2026 Article 760 fire alarm requirements. Always consult the actual NEC and NFPA 72 code text, and verify requirements with your local Authority Having Jurisdiction. Fire alarm installations may also be subject to state fire marshal requirements.

Sources

• IAEI Magazine: NEC 2026 Significant Code Changes
• Fire Alarms Online: Fire Alarm Wiring Based on NEC Article 760
• Nassau National Cable: FPLP vs. FPLR Cable Selection
• IAEI Magazine: Electrical Inspector's Notes to Fire Alarm Systems
• Mike Holt: Article 760 Fire Alarm Systems