Addressable Fire Alarm System

Even if you're not ready to take the plunge into fire alarm system design and installation just yet, you should still know the fundamentals in order to perform emergency work. This includes knowing how to disarm the control panel of a deranged system and troubleshoot the heads, pull stations, horns, and zone wiring so that the equipment goes back online, restoring fire protection for the building. Because these ailments can be frequent with older and newly commissioned systems alike, it's important for electrical contractors to understand the basics of fire alarm systems.

A medium-sized control panel with touchpad for alarm and trouble silence and system reset is shown above. Referring to the installation manual, you can use the touchpad to program the systems many options.

The modern fire alarm system is capable of detecting smoke and heat from a small flame, water flow in a sprinkler system or an activated pull station, and reporting this information to on-site personnel via dedicated phone line to any location in the world. Although a seemingly straightforward device from an installation standpoint, fire alarm work can be quite complex, especially when you consider the enormous moral and legal responsibilities involved. There have also been some recent updates to the technology over the last few years worth noting.

Recent advances. The latest major development in the fire alarm system arena has been the introduction of the addressable head. Before these updates, in the event of an alarm, the alphanumeric display at the control panel indicated which zone was affected something like Fire Alarm Zone 6, East Wing Third Floor. With an addressable head system; however, the exact location is pinpointed. Moreover, the addressable head system has enhanced diagnostic capabilities. This is a great advantage because when a system goes down, time is of the essence in restoring fire protection to the building.

To upgrade to addressable heads, it's not usually necessary to do a complete system replacement. Typically, installers must put in new heads, pull some extra wire, and insert new printed circuit cards into the existing control panel. Each new head possesses an address, which conveys its exact location. You may be asking yourself if this means a spare head has to be kept in inventory for each location. No, each initiating device has on its back a set of DIP switches by means of which you enter a binary number that comprises the address prior to installation. If replacement is necessary, use a small screwdriver to set the DIP switches on the new device.

The option to upgrade with addressable heads or to completely replace a legacy system has to be carefully considered by building owners with the input of in-house electricians and outside consultants. For a large set of buildings, the expense to upgrade can be formidable.

For example, besides addressable and non-addressable heads, there are high- and low-impedance initiating devices, 2- and 4-wire circuitry, and various operating protocols. These are reflected in the different states a control panel can be in as reported by the alphanumeric display. A system may also be power limited, or, less commonly, non-power limited.

In addition to familiarizing yourself with the most recent technology trends as outlined above, it's also important for electrical contractors to realize how sensitive these devices are to certain design, installation, and operational issues all of which can result in lost revenue, unplanned downtime, and unhappy customers. Here's a good example. Say an expensive commercial building is all but finished; however, the fire alarm doesn't pass inspection, meaning the facility cannot legally be used. As a few rattled electricians work feverishly to get the bugs out of the system, the owners lose thousands of dollars every day. Another potentially problematic scenario might involve slightly creased conductors coming out of a conduit connector at the detector head base. Although this situation would pose no problem in ordinary power or telephone circuits, it could throw one of these systems into false alarm.

Realizing that these types of unforeseen circumstances can throw a wrench into even the best conceived plans, it makes sense for contractors to review fundamental design, installation, and operational considerations for fire alarm systems to keep their skills sharp.

Design considerations. Typically, a fire alarm system is made up of the following components:

Addressable Fire Alarm System Intelligent Addressable Fire alarm Systems allow the location of a fire to be precisely located from the control panel. The use of looped wiring allows the system to function normally even with an open circuit in the loop wiring. These systems offer benefits in speed of detection, identification of the location of a fire and easier maintenance. The wiring cost of system can be reduced by the use of single pair of wires for up to 200 devices to the system, allowing cost savings in the wiring of large systems.