The primary focus of the National Electrical Code (NEC) is safety, and it offers specific requirements for how to install wiring and help ensure the safety of both the contractor and the building occupants. In addition to the safety issues the NEC addresses, a professional contractor needs to focus on the reliability requirements that the Code may not specifically state; these should stand as a goal for all fire alarm system installations.
The most commonly misunderstood Code requirement concerns the mechanical execution of the wiring installation. Article 760.24 requires workers to “Install equipment and cabling in a neat and workmanlike manner.” Multiple interpretations of this have arisen among contractors, building owners and authorities having jurisdiction.
Almost every installation I’ve seen while witnessing a final acceptance test has had violations of this requirement. Maybe stakeholders assume installers will have learned how to perform a neat and workmanlike installation during on-the-job training, or perhaps time pressures that arise have forced installers to overlook this component. Whatever the cause, this stands as a serious impediment to the overall reliability and serviceability of a fire alarm system.
I often first encounter this critical issue when the contractor opens the door to the fire alarm control unit. I see a jumble of unmarked wires crisscrossing in front of the electronics. As a result, I suspect the rest of the installation does not adhere to the requirements of Article 760.24.
The installing contractor should carefully place the cables inside a fire alarm control unit on the sides of the electronics, and use cable ties to keep the cables from spilling over onto the circuit boards. He or she must maintain clear access to the electronics, and the installer should employ a carefully thought-out system of cable identification so that each conductor has an identifying number that anyone can reference on a cable chart. This one simple step greatly enhances troubleshooting.
Additionally, when installing cables above a suspended ceiling, the contractor must support the cables by using the building structural components. This will help ensure that any other work taking place above the suspended ceiling will not damage the cables and that the ceiling tiles can easily be raised to gain access to other equipment that a contractor may need to service.
In addition to the cable numbering system for the fire alarm system control panel, a contractor should employ a similar strategy for fire alarm circuits at all terminals and junction locations. The cable numbering system must identify every conductor, its origin point and its termination point. Doing this will comply with the requirements of Article 760.32.
Generally speaking, the Code requires a junction box for all devices and connections. In some cases, a contractor will assume that, because the fire alarm wiring may qualify as “low voltage,” he or she can skip the back box for a manual fire alarm box (pull station) and still comply.
This assumption will only prove true if the nationally recognized testing laboratory has listed the manual fire alarm box—or other device—for installation without an enclosure. Since someone actuating the manual fire alarm box will pull down on the handle, actuation—without a back box or enclosure—may pull the device off the wall. So saving the rather minimal cost of a back box will ultimately decrease the system reliability. Therefore, I always recommend the use of a back box or enclosure.
If you replace an existing fire alarm system and do not use all of the cable originally provided for installation, the Code requires you to remove all accessible portions of the existing unused cable. The exception permits you to retain the unused portion in place if you terminate or identify it for future use.
A reduction of the operational reliability of a fire alarm system and an increased potential for false alarms remain the major concerns when a system has not been installed in a workmanlike manner. Contractors have to remember that the fire alarm system is intended to provide life safety to the occupants of the building. If the wiring does not comply with the NEC, you have failed to meet the minimum requirements.
More important, the system must operate properly when called on to do so. It is simply unacceptable for any contractor to provide a poorly installed system. The wiring should not only meet the minimum Code requirements but also should be installed in such a fashion to ensure easy repair should a problem occur. When you design the wiring scheme for a fire alarm system installation, you must include minimum downtime on your list of goals in your planning process.
Some contractors will proudly state that they always meet the Code, which is very important. However, to ensure you are providing the proper level of life safety, you need to pay closer attention to the details of the cable installation and all other aspects that go into achieving a workmanlike manner.