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Protecting Critical Building Circuits From Fire – Codes, Standards And Why Splices and Systems Matter

Fire safety and electrical codes and standards have been adopted worldwide and have been continuously improved to help ensure the best methods and practices for designing buildings. 

Important Area in Building Design

One area of primary importance in building design is the protection of critical electrical circuits such as alarms, emergency lighting, electrical fire pump feeds, emergency generators and air handlers as well as electrical feeds for emergency elevators.


The NEC is very particular and insists upon Approved Systems when it comes to Fire Rated Wiring. It’s a real-life example of a chain being only as string as its weakest link.  According to Article 728.4 of the NEC you cannot mix components from different manufacturers unless they have been tested together at UL.

  • NEC 728.4 General. Fire-resistive cables, fire-resistive conductors and components shall be tested and listed as a complete system, shall be designated for use in a specific fire-rated system, and shall not be interchangeable between systems.

Similarly, and for good reason, the NEC is very specific when it comes to splices.

  • NEC 728.5(H) Splices. Only splices that are part of the listing for the fire-resistive cable system shall be used. Splices shall have the manufacturer’s installation instructions.

The CEC and National Building Code of Canada (NBCC)

The CEC and National Building code of Canada (NBCC) have complementary information regarding Fire Resistive Electrical systems and their constituent components.

Approved Splices Must Be Available   

There are scenarios where having approved splices available when needed can become critical to successful project completion. One scenario is when the cable is being pulled on-site and it becomes apparent that due to unforeseen routing issues, or damage during construction, the cable must be cut, the two segments pulled into place independently and the cable spliced back together.

Another common scenario is when installations are planned to be completed in multiple phases.  Owners may want to use just a section of the building that has already been completed. In the future, they will install the other parts of the circuits as the other section of the building is built.  They would need a UL-listed splice to splice the two sections of the circuit together. 

UL Product IQ Database 

UL’s Product IQ Database UL Product iQ is the definitive source for understanding what specifically is approved for each manufacturer’s fire-resistive system. It’s free and easy to create an account. Search on FHIT (US) and FHIT7 (CAN) and you will see all the manufacturers’ system listings including details such as which approved splices are available, which support brackets are approved and the maximum bracket spacing and other important details.

One critical thing to note – If it’s not specifically called out in the listing it’s not approved!

Details are important and especially when they have to do with fire protection. It’s definitely worth the effort to verify all details and anticipate common problems to avoid expensive mistakes and most importantly, to provide a safe and fully Listed system solution.

Find our product specifications on Deltek Specpoint.