Preventing a Communications Breakdown

Sometimes the most basic of considerations on a job is enough to cause a major breakdown in communications. Whether it is one of the two RJ31X jacks that link a digital alarm communicator transmitter (DACT) within a fire alarm control panel (FACP) to the public switched telephone network (PSTN), ground fault or a short circuit, communications with the central station can be impaired. This can delay or prevent fire department response.

Assuring RJ31X Integrity Is Key
When fire technicians provide central station monitoring with the fire alarm systems they install, National Fire Alarm Code specifies a variety of protections associated with signal transport. One of these protections is the use of signal paths.

Although this works well to get fire signals to the central station, it does not address the local issue of sabotage or inadvertent disconnection of one or both RJ31X jacks. One way veteran fire technicians often assure RJ31X integrity on premises is to include the supervisory contacts within the jack in their fire panel detection scheme.

As can be seen in the following illustration (see diagram on page 28 of August 2004 print edition of SSI), you must place a short across terminals 2 and 3 inside the RJ31X jack. This is usually accomplished using a short piece of wire, usually 22 AWG, solid. It is also possible to use an end-of-line resistor for this task. Of course, this will be determined by the operating parameters of your FACP.

At the end of the RJ31X cord, inside the fire panel, you must then place the orange and black conductors on an initiating zone and program that zone for normally closed supervisory function. Whenever the RJ31X jack is physically disconnected, the FACP will indicate a supervisory condition at the panel, remote annunciators and at the central station through the second signal path.

Bond 2nd Ground Rod to Primary
Some low-voltage system installers believe that it’s proper to install a dedicated ground rod when they install a new fire alarm, as well as other low-voltage systems. Although this practice is valid, Nick Markowitz, owner of Markowitz Electric Protection in Verona, Pa., says specific rules must be followed to assure electrical safety as set forth in NFPA 70, National Electric Code (NEC), published by the National Fire Protection Association (NFPA).

Most of the low-voltage installers who use this second ground rod method cite former problems they’ve had when they used cold water pipes or the main water line that enters the facility. Problems can occur in both instances especially when someone has replaced any portion of the metal pipe with plastic.

Plastic is often used to replace corroded and leaking metal pipes within a facility. It is also used with the metal water pipe that enters a structure with the water main out at the road. In either case, when plastic is used and the fire technician is not aware of it, earth ground may not be assured. This essentially constitutes not only a violation of NEC, but also represents a real life-safety threat to the occupants as well as other workers.

When using a second ground rod, Markowitz says to always bond it to the primary ground rod already in the building with a #6 bare copper wire. Install it between the new ground rod and the neutral bar in the main electrical breaker panel. Where more than one breaker panel is involved (see diagram on page 30 of August 2004 print edition ofSSI), connect the multiple grounds to the #6 bare copper wire that fastens to the primary ground rod.

Markowitz advises fire technicians to always use approved connectors when doing this work. If you have any doubt, call a qualified electrician for advice.

Prime Contractors Advise Clients
There are those in the fire alarm installation business who invariably believe that knowing what kind of protection to buy falls on someone else’s shoulders. When a problem crops up during the final inspection, for example, these folks often point their finger at the electrical engineer or architect — even the client — to convince the fire inspector that it wasn’t their fault that the system specified was not sufficient for the application.

When installing a fire alarm system for central station service, for example, Section 5-2.2.3 of NFPA 72, National Fire Alarm Code, clearly states that such responsibility falls on the prime contractor responsible for its installation:

“The prime contractor shall conspicuously indicate that the fire alarm system providing service at a protected premises complies with all the requirements of this code by providing a means of their party verification, as specified in 5-2.2.3.1 or 5-2.2.3.2.”

There are two ways to accomplish this: The first, cited by NFPA 72, involves the display of a third-party certificate. To comply, the certificate must be installed within 36 inches of the FACP. Or, in the absence of a FACP, it must be placed within 36 inches of a fire alarm component.

The most common approval method involves what NFPA 72 refers to as a placard: “Fire alarm systems providing service that complies with all the requirements of this code shall be conspicuously marked by the central station to indicate compliance. The marking shall be by one or more placards that meet the requirements of the organization that has listed the central station and requires the placard” (Section 5-2.2.3.2.1, NFPA 72, 1999 Edition).

Code calls for such a placard to be a minimum of 20 square inches. Like the certification notice, the placard should be located within 36 inches of the FACP, or, in the absence of a FACP, within 36 inches of a fire alarm component.

To further illustrate the actual point of responsibility, regarding the compliance of any new system, “Fire alarm system service that does not comply with all the requirements of Section 8.2 shall not be designated as central station service” (Section 8.2.4.3, 2002 National Fire Alarm Code Handbook, pp. 320).

In Appendix A, relating to the same publication and section, “It is the prime contractor’s responsibility to remove all compliance markings (certification markings or placards) when a service contract goes into effect that conflicts in any way with the requirements of 8.2.4.”

In conclusion, the prime contractor (installing company) is required to know when a new system fails to comply with code, not the electrical engineer, architect, general contractor or the individual or organization that contracted to have it installed.

If you enjoyed this article and want to receive more valuable industry content like this, click here to sign up for our FREE digital newsletters!

Security Is Our Business, Too

For professionals who recommend, buy and install all types of electronic security equipment, a free subscription to Commercial Integrator + Security Sales & Integration is like having a consultant on call. You’ll find an ideal balance of technology and business coverage, with installation tips and techniques for products and updates on how to add to your bottom line.

A FREE subscription to the top resource for security and integration industry will prove to be invaluable.

Subscribe Today!

Get Our Newsletters