Why Your Fire Alarm Watches the Fire Department’s Radio System

Firefighters rely on their radios inside your building, and a building's structure can weaken the signal. Washington’s fire code answers that with a radio system inside the building, and it makes your fire alarm responsible for reporting when that system has a problem.

What the system is

The code calls it an emergency responder communication enhancement system. You may also hear ERCES, ERRCS, or DAS (a distributed antenna system, the network of indoor antennas). It picks up the public safety radio signal outside the building and rebroadcasts it inside, so responders can talk from a stairwell or a basement.

Which buildings need one

WAC 51-54A-0510 says an approved system “shall be provided in all new buildings,” based on the public safety coverage measured at the outside of the building. The local fire code official can decide a building doesn’t need one, or accept an approved alternative, so the answer for your building comes from your fire department. Existing buildings are covered separately, under Chapter 11 of the fire code.

Cities can add their own rules. Bellevue, for example, amends this section, and sets acceptable coverage at 95 percent of all areas on each floor and 99 percent of critical areas.

Seattle has its own version

Seattle sets different thresholds in its own fire code. The Seattle Fire Department’s Client Assistance Memo 5123 says these buildings need a system, unless the owner shows that radio coverage already meets the minimum standard:

• All new high-rise buildings.
• New buildings with 50,000 square feet or more in total, 10,000 square feet or more of basement, or occupied floors more than 30 feet below the lowest level of exit discharge. Smaller new buildings are exempt.

Existing high-rises without approved radio coverage or a wired fire department communication system have to add one or the other. King County’s public safety radio system has also been replaced by the Puget Sound Emergency Responder Network (PSERN), and building owners have to re-tune or recommission their equipment for it.

Where your fire alarm comes in

Under section 510.4.2.5, the radio system’s supervisory and trouble signals (the messages that say something needs attention) must be monitored by a supervisory service and shown on the fire alarm system, in accordance with NFPA 72. The code lists eight conditions:

• Loss of normal AC power
• Battery charger failure
• Donor antenna malfunction (the outside antenna that reaches the public safety network)
• Failure of an active RF-emitting device (equipment that transmits radio signal)
• Low battery capacity, at a 70 percent reduction
• Active system component malfunction
• Malfunction of the communications link between the fire alarm and the radio system
• Oscillation of an active RF-emitting device (a fault where the equipment feeds back on itself)

Each condition is shown separately on the fire alarm. The alternative is one combined signal on the fire alarm, if the radio system has its own dedicated panel showing each condition individually.

What has to be tested each year

The building owner or their agent has to have the system inspected and tested every year, and whenever structural changes could affect its performance. The list in section 510.6.1 includes:

• An in-building coverage test (annual testing isn’t required inside dwelling units in residential occupancies).
• Signal booster levels, and backup batteries and power supplies tested under load for an hour.
• If the building has a fire alarm, a test that the fire alarm is properly supervising the radio system, done by simulating alarms to the fire alarm control panel.
• A record kept on the premises and a report submitted to the fire code official.

This is specialized work. In Seattle, the people who design these systems and lead acceptance testing need a valid FCC general radio operator license plus in-building system training. Annual reports go to the Seattle Fire Department through The Compliance Engine within 7 calendar days, and a system out of service for more than eight hours has to be reported to the fire code official.

What to do

• Find out whether your building has one. The code calls for a sign on or next to the door of the room with the main equipment.
• Check your fire alarm panel. Ask whether the radio system’s signals actually come through to it.
• Look at your last test report. Make sure it covers the fire alarm supervision test and went to your fire department.

More about fire alarm monitoring →

Sources

1. Washington Administrative Code, WAC 51-54A-0510, Emergency responder communication coverage.
2. Seattle Fire Department, Client Assistance Memo 5123, Emergency Responder/Public Safety Radio Amplification Systems Using PSERN (updated November 2024), and Systems Testing.
3. Bellevue City Code, 23.11.510, International Fire Code Section 510 amended.