In commercial fire alarm systems, cable selection is as important as device placement or panel configuration. The National Electrical Code (NEC) defines specific cable types for different building environments, and two of the most common are FPLP and FPLR cable. While their names may seem similar, each has distinct characteristics, applications, and code requirements. Choosing the wrong one can mean costly rework, failed inspections, and reduced system safety.

Working with contractors, system designers, and facility managers every day makes sure projects meet safety and code requirements. Understanding the differences between FPLP and FPLR is key to selecting the right product and keeping fire alarm systems compliant and reliable.

What Is FPLR Cable?

FPLR cable stands for Fire Power-Limited Riser Cable. It is designed specifically for vertical spaces, or risers, that run between floors in commercial buildings. The primary purpose of riser-rated cable is to prevent fire from traveling up through vertical shafts, which could rapidly spread flames between levels.

FPLR cable jackets are tested to meet specific UL standards, which measure flame spread in vertical installations. While FPLR provides robust fire resistance, it is not designed for use in air-handling spaces. Using it in those environments would violate code and potentially compromise safety.

Some projects require FPLR circuit integrity cable, which adds protection to maintain system operation for a specified period during a fire. This type is often called for in mission-critical facilities, such as hospitals or emergency response centers.

Because FPLR is a non-plenum fire alarm cable, it is typically less expensive than its plenum-rated counterpart. However, cost savings should never override proper placement according to code requirements.

What Is FPLP Cable?

FPLP stands for Fire Power-Limited Plenum Cable. This type is specifically engineered for areas used for air circulation, such as above suspended ceilings or within HVAC return air ducts. Also known as plenum spaces, these present unique hazards because they can act as channels for smoke and fire, spreading them quickly through a building.

FPLP cables are tested to more stringent UL standards to address this risk, which measures flame spread and smoke generation. A plenum-rated fire alarm cable must produce minimal smoke and resist flame propagation, protecting occupants and property.

Because of these enhanced safety requirements, FPLP cable often features low-smoke, flame-retardant insulation and jackets made from specialized materials. While it typically costs more than FPLR, the performance standards it meets are necessary for compliance in air-handling environments.

Plenum Cable vs. Non-Plenum Cable

When comparing plenum cable vs non plenum cable, the key difference lies in where each can be installed. Plenum-rated cables like FPLP can be used in both plenum and non-plenum environments. Non-plenum cables like FPLR are limited to spaces without air circulation, such as vertical riser shafts or general building areas.

The NEC (Article 760) specifies when each type is required, and building inspectors look closely at these placements during approval. Installing a non-plenum fire alarm cable in a plenum space is a violation that can result in failed inspections and mandated replacement. All of a sudden, it becomes an expensive and time-consuming mistake.

From a safety perspective, plenum-rated cables reduce the toxic smoke and rapid flame spread risks associated with standard cable jackets. This makes them essential in any environment where air-handling ducts are present.

Comparing FPLP and FPLR: Key Differences

Although FPLP and FPLR share a similar purpose in transmitting fire alarm signals, they are designed for very different environments. FPLP is intended for use in plenum spaces, which are air-handling building areas. These spaces require cables that pass stringent flame spread and smoke tests, such as the UL 910 standard, to ensure minimal smoke production and limited flame propagation in the event of a fire. Because of these strict requirements, FPLP cables generally cost more but offer the flexibility to be used in both plenum and non-plenum areas.

FPLR, on the other hand, is built for vertical riser shafts between floors and, when UL-listed, is tested to the UL 1666 flame standard or an equivalent riser flame test. It is flame-resistant but does not meet the smoke and flame restrictions required for plenum spaces. As a result, it cannot be used in any NEC-defined plenum areas where the cable is exposed to ventilation airflow. FPLR cables are typically less expensive and are ideal for non-plenum areas, especially where vertical fire spread prevention is a priority.

In short, FPLP provides broader installation flexibility and higher fire safety ratings, while FPLR offers a cost-effective option for riser applications. The correct choice always depends on the specific environment in which the cable will be installed, along with the applicable code requirements.

NYC-Specific Considerations

Additional requirements can apply in New York City. Local codes often mandate NYC shielded FPLP or NYC shielded FPLR cables for certain fire alarm installations. The shield protects against electromagnetic interference, which can be important in dense urban environments with numerous electronic systems operating close together.

These cables must also be approved by the NYC Department of Buildings and may need to be listed by the Fire Department of New York (FDNY) for use in regulated installations. Submitting the correct spec sheets and certification documents to the Authority Having Jurisdiction (AHJ) can help avoid delays.

How to Choose the Right Fire Alarm Cable for Code Compliance

When helping customers choose between FPLP and FPLR, these three questions must be answered:

1. Where will the cable be installed? If it passes through any air-handling spaces, FPLP is required.
2. What are the local code requirements? Some cities, like New York, have additional rules on shielding or listing.
3. What performance standards must be met? Certain environments may require a FPLR circuit integrity cable or a higher-grade plenum-rated option.

Other factors include building design, environmental conditions, and budget. However, the driving factor should always be compliance. The wrong cable can fail inspection and compromise life safety systems.

Examples of Common Applications

• Office Towers: FPLR in vertical risers, FPLP above drop ceilings with HVAC air return.
• Hospitals: FPLP for patient care areas with air circulation, shielded variants for sensitive equipment rooms.
• Schools and Universities: FPLP for common areas with air plenums, FPLR in dedicated riser shafts.

These examples illustrate how cable types often work together within the same system, each serving its designated environment.

Additional Resources

For more technical details, review our Fire Alarm Cable Resource Page.

If you need help navigating specifications or NEC references, our team can walk you through the options and match them to your project’s needs. Contact us directly to start the conversation.

Selecting between FPLP and FPLR cable is a technical choice and a matter of safety and compliance. The NEC and local codes define where each type must be used, and understanding those requirements is the best way to avoid costly mistakes. From plenum cable vs non plenum cable considerations to specific mandates like NYC shielded FPLP and NYC shielded FPLR, every detail matters.

By knowing the differences in construction, fire rating, and application, contractors and designers can make informed choices that protect both the integrity of the system and the safety of building occupants. The right cable in the right place keeps fire alarm systems operating as intended, keeping your project compliant from day one.