Fire & Life Safety: Re-Use or Recycle?

March 11, 2014
A guide to code-compliant panel replacement

Re-using the shell of a fire panel is a conundrum that recently struck this integrator, who was replacing an existing, outdated control with a new addressable panel in a nursing facility. This old panel was very large and had a lot of circuit wiring piped into it.

Q: “I’d like to locate the new panel, enclosure and all, inside this space. Do you know of any reason I cannot install the new fire alarm control panel inside the empty cabinet of the old control panel?”

A. Let’s think this through logically — first, don’t be tempted to remove the circuit board from the new addressable control panel and mount it in the existing cabinet, no matter what model or manufacturer. The metal enclosure with the addressable panel was put through the listing process with the electronics mounted inside it and was tested for lightning suppression with the conduit knockouts installed in locations approved by the manufacturer. These wiring entry locations help maintain a separation from non-power limited wiring. The listed panel must be treated as the single assembly described in the installation instructions.

Next, look at the new panel’s instructions and how NFPA 72 limits your choices of indoor locations. NFPA 72 will set the basic ambient conditions under which it may be installed — for example, you should not install the panel where the temperature will exceed 100° or 32° F, nor in damp, dirty or corrosive environments. Even areas where the temperature fluctuates wildly within the allowable range or where it may be subject to vibration can shorten the panel’s reliable lifespan; so, unless the manufacturer’s written instructions provided with the panel allow different ambient conditions other than these provided by NFPA 72, you will not be permitted to get too creative.

Next, consider the National Electrical Code (NEC) generic rules for boxes and raceways. You will not make any splices that are not within the new addressable panel or in electrical junction boxes with their covers attached. Maintaining a code compliant installation should be your goal, even if the larger panel’s door is removed.

Finally, is there anything similar already permitted by the codes? What if your addressable panel’s location was subject to occasional water spray, say during weekly clean ups. To protect it, the NEC would specify protecting your panel with a special water resistant (i.e. NEMA-4) rated enclosure that is sealed with a gasketed door. Your effort to provide less downtime (and better protect the system against tampering) is no less valid than using a NEMA-4 rated enclosure to protect your panel from occasional splashed water.

Since this project is not a replacement of like equipment, you will have to submit plans to the local authority having jurisdiction, for approval. In the documentation you provide the local code authority, simply explain how you’re going to use the existing cabinet space to install the new control panel. It’s better to have this discussion out of the way before the final inspection.

Elevator Smoke Detector Compliance

My second question comes from an installer with a long-time customer who has added a new wing with a second floor to an existing single-story office building. An elevator was installed in the new wing to serve the second floor. Since the existing fire alarm system was not addressable, the installer used four-wire, relay-base smoke detectors to provide elevator recall, with an end-of-line power supervision relay after each recall detector. Obviously the two elevator lobby smoke detectors’ relays are not going to be within three feet of the elevator equipment.

Q: “Researching this issue in the 2013 edition of NFPA 72 has caused me some confusion. What am I missing?”

A. Before the 2013 edition of NFPA 72, the rule regarding emergency control functions made more sense. Lucky for you, your state is currently using the 2010 edition of NFPA 72 which, in section 21.2.4, states “A listed relay or other listed appliance connected to the fire alarm system used to initiate control of protected premises emergency control functions shall be located within 3 ft. of the controlled circuit or appliance.” Because you are bringing the “controlled circuit” to the lobby smoke detectors, you will still be in compliance.

In the 2013 edition of NFPA 72, someone decided that this rule needed work, so two new terms were invented. The new 2013 wording for section 21.2.4 was changed to read: “Emergency control function interface devices shall be located within 3 ft. of the component controlling the emergency control function.”

I think they made a mistake when omitting the “controlled circuit” wording. Without this wording, it seems that only digital signals or addressable relay modules (on digital circuits) may now be used, and relay-bases cannot since the detector is seldom going to be located within three feet of the “Emergency Control Function Interface Device.” This omission might be a typo since a diagram in the 2013 Annex still shows a relay-based smoke detector being used for elevator recall. It’s doubtful that relay-based detectors are not going to be considered to be an “emergency control function interface device” when your state adopts the 2013 edition.

Here are two new terms from the 2013 edition of NFPA 72 affecting the three-foot rule:

3.3.90 Emergency Control Function Interface Device — a listed fire alarm or signaling system component that directly interfaces with the system that operates the emergency control function. Emergency Control Function Interface — the interface between the fire alarm system emergency control function interface device and the component controlling the emergency control function.

Greg Kessinger is SD&I’s fire alarm and codes expert and a regular contributor. Email him your fire & life safety questions at [email protected].