A guide to fire alarm interdisciplinary coordination

Many understand the basics of fire alarm layouts including pull stations, notification devices, heat and smoke detectors and coordination with sprinkler systems, but often there are other items in the design that garner less attention. These items may receive less attention because they involve disciplines other than fire protection and sometimes the proper coordination conversations are not had between design team members to address the issue.

The fire alarm designer will need to coordinate with many team members: architects, engineers (mechanical, electrical, telecom, security, fire protection) and consultants (door hardware, kitchen equipment, signage). Because communication is a two-sided endeavor, if you are not the fire alarm designer, know that some aspects of your design may interface with the fire alarm system.

For each topic, this will address the typical design solutions, what questions need to be answered and the information that needs to be shared to develop the proper design.

Figure 1: The Quarry Run Regional Operations Center is a mission critical facility with redundant systems designed not to fail in the event of man-made or natural disasters. The suppression and the fire alarm systems were coordinated and provide a fully integrated system. Courtesy: Page

Fire alarm panel locations

Fire alarm drawings are often created in 2D space, which does not account for the size of the cabinets needed. It is important to plan for the wall space needed with the proper clearance and room among the other disciplines. When panels are grouped together, it often claims more space than one would expect. Because fire alarm control units and either electrical or telecom often share rooms together, the space needs to be coordinated.

Fire alarm control units are typically 24 inches wide and auxiliary power supplies are typically less than 12 inches wide. The height of the fire alarm control unit depends on amount of equipment needed inside of the panel. If the design calls for an amplifier, voice control unit or multiple signaling line circuit cards, additional bays within the cabinet are needed, which results in a taller cabinet.

Very early smoke detection apparatus units (air-aspiration smoke detectors) and their associated power supply also take up 12 inches of wall space. It is good practice to reserve wall space above and below the control unit so it can be expanded if additional bays are needed or if you want to stack auxiliary power supplies or VESDA units. Conduit and wireway adjacent to the panels also need to be accounted for.

Without spatial coordination for fire alarm equipment, oftentimes the fire alarm panel will end up being located in less-than-ideal locations, for instance, an office, a highly trafficked corridor or feature lobby. This is not wrong from a code perspective, but not ideal for the end-user or responding fire department.

Figure 2: Example of fire alarm equipment wall layout and a stacked panel arrangement. Courtesy: Page

Fire alarm power requirements

If the same person or firm is not designing both the electrical system and the fire alarm system, there needs to be coordination to ensure the fire alarm equipment receives the power it needs. Fire alarm equipment requires a dedicated circuit for only fire alarm systems. The circuit can be on normal building power because the fire alarm equipment is typically provided with battery backup as a secondary source.

To coordinate this item with electrical, it is best to provide a drawing markup of all the fire alarm equipment that will need power. This type of equipment includes fire alarm control units, auxiliary power supplies used to control notification appliance circuit circuits, preaction or clean agent releasing panels and VESDA equipment.

On the fire alarm drawings, highlight the equipment location and add some notes on the power needs. Looking at typical fire alarm equipment cutsheets the power requirements are not a large load compared to other systems. In general, the electrical engineer provides a 10-ampere circuit to single pieces of equipment or a 20-ampere circuit to groups of equipment. That circuit capacity should meet the fire alarm equipment need most of the time.

From an electrical perspective, the total load and circuits need to be provided in the field. If this is not coordinated during design, then planned spare circuits may be used or new panelboards and circuits may need to be installed resulting in likely change orders. Also, beyond the circuits and breakers, conduit and wiring will need to be run out to each piece of fire alarm equipment.

Fire alarm circuits need to be dedicated to fire alarm purposes and have a lock on the breaker switch. Multiple fire alarm devices can be on the same circuit.

Figure 3: Example of a dedicated 20-ampere circuit for a fire alarm panel on an electrical panelboard schedule. Courtesy: Page

Survivability

When using partial relocation strategies common to health care, high-rise or large footprint buildings, survivability needs to be considered in the fire alarm design. This may require input from the architectural team if fire-rated construction needs to be used.

The purpose of providing pathway survivability is to protect circuits and equipment that are needed to notify other portions of the building in case of a fire. For instance, if circuits are crossing a smoke compartment boundary, the circuit serving the adjacent compartment needs to be protected. In this case, if there is a fire in the primary compartment, the adjacent smoke compartment will still receive its notification.

Likewise, in a high-rise, if there is a circuiting crossing one floor that provides notification to the floor above that circuit needs to be protected so that if there is a fire on the primary floor, the floor above can still receive its notification message.

The survivability requirements have changed slightly in the last few NFPA 72: National Fire Alarm and Signaling Code editions, so make sure to follow the applicable requirements. Architects may not be aware they need to fire-rate rooms because those requirements do not come from the building code. If there is a need for a horizontal run that needs to be protected, a horizontal fire rated shaft may be needed, which requires architectural coordination.

An alternative to the horizontal shaft is to use rated circuit integrity cabling. The CI cabling is currently UL listed again after losing it for a period of time in 2012 due to changes in the UL 2196: Fire Test for Circuit Integrity of Fire-Resistive Power, Instrumentation, Control and Data Cables fire testing standard.

Figure 4: The fire alarm system at the Austin Bergstrom International Airport East Infill Terminal required the coordination of a multidisciplinary team to ensure that the system would accurately support the facility while also enhancing the design intent of the architects. Courtesy: Tim Griffith, Page

Elevators

When an elevator is used in a building, it will have some level of interface with the fire alarm system. The type of elevator, the construction of the elevator and the fire suppression system associated with the elevator will come into play when determining the type of fire alarm interface is required.

To properly coordinate the fire alarm system with the elevator, some information will need to be gathered from other designers. First, it needs to be determined the type of elevator that is being provided. The elevator can be a traction type, hydraulic type or machine-roomless. Second, it needs to be determined where the sprinklers will be located.

Ask these questions: Are there sprinklers at the top of shaft, bottom of shaft and are there sprinklers in the elevator machine room? Is there a separate control valve and flow switch for the sprinklers?

One thing to also note is that many jurisdictions have their own requirements regarding the sprinkler and alarm requirements for elevators, so make sure to double-check with the authority having jurisdiction.

Generally, there are smoke detectors at the elevator lobbies for elevator recall and inside the elevator machine room. As far as detection in the hoistway, heat detectors will be placed near the locations of the sprinklers if they are present. Also, if the elevator has its machinery located within the hoistway, a smoke detector will be necessary at the top of the shaft.

The elevator controller is where additional fire alarm outputs are required. Here you will need to provide relays for primary recall, secondary recall, inside cab firefighters warning and shunt trip (if applicable).

Figure 5: Example wiring diagram for connections to elevator controller and detection devices. Courtesy: Page

Combination fire and smoke dampers

Combination fire/smoke dampers are commonly required where ductwork enters/exits shafts and where it passes through two-hour rated construction, at air handling units for isolation. The dampers require power, control and the damper itself to operate. Generally, there is an associated duct detector, which provides the control signal to close the damper.

The power for the damper typically would be 120 volts alternating current or 24 volts direct current, most commonly 120 vac on most projects. In this instance, electrical will need to provide power to the circuit. Fire alarm would need to provide a control module and a relay to cut the power to the normally energized circuit to close the damper. The control module connects to the fire alarm signaling line circuit and provides a low-voltage output to the relay. The relay leverages the low voltage output to a higher voltage, which allows for the 120 vac circuit to open.

When coordinating combination fire/smoke dampers, the design responsibilities should be assigned as follows: the mechanical engineer places the dampers based on the code analysis, the electrical engineer provides power to all of the damper locations and the fire alarm designer provides the duct detector, relay and relay module to control the damper.

Door hardware

Knowing which doors require a fire alarm interface is important to prevent issues during construction with sequence of operations and equipment procurement. To coordinate, it’s important to have conversations with the architect and security designer. Oftentimes there is a specialty door hardware consultant as well.

To find the information for coordination, the architectural door schedule is a good place to begin. Often, there is information about the door hardware kit that will identify if there is a magnetic hold open, delayed-egress or shutter associated with the door.

However, sometimes only the door hardware type is listed on this schedule and that requires the need to look into the door hardware specification for the information. It is much simpler to have a meeting between the design disciplines and markup a drawing on where the connections need to occur, so everyone agrees.

For a magnetic hold open, typically there is a smoke detector to activate the hold open and a control module and relay to turn off the power, which de-energizes the magnet to close the door. Another method is to have the magnetic hold be powered by the 24 vdc fire alarm system. This auxiliary power would come from an auxiliary power supply unit. When powering the door hold from the fire alarm system, it also needs to be determined if fire alarm provides the magnetic holds or it is provided via the door hardware vendor.

When doors need to unlock under a fire alarm, there needs to be coordination between fire alarm and security. Typically, the security designer will have an access control panel that controls all of the magnetic or electric locks. For fire alarm, a control module needs to be located next to the access control panel and connected to it. The control module sends an output to the access control panel, which then unlocks whichever doors will need to unlock upon a fire alarm.

When using delayed-egress hardware, a signal needs to be sent from the fire alarm system to the delayed-egress hardware if a sprinkler waterflow switch occurs. This ensures the door hardware will open in the event of fire and not just when an occupant initiates the door hardware timer countdown. To accomplish this, a control module is placed in the vicinity of the delayed-egress hardware and connected to its control junction box typically located above the door frame.

Figure 6: See typical combination fire/smoke damper equipment arrangement and points of connection. Courtesy: Page

Phone/fiber interface

Fire alarm signals are required to be monitored outside of the protected premises by a third-party monitoring agency or 24/7 emergency dispatch center. Other times, there is a campus with multiple buildings, each with its own fire alarm control unit, which creates a network over fiber and reports back to a 24/7 monitoring center.

In either case, there needs to be a means for which the fire alarm signals leave the building and make their way to a monitoring location. This traditionally has been done over phone lines and now phone to voice over internet protocol networks. Using cellphone signals is now also an alternative to use and some jurisdictions even use radio transmitters. Regardless of the methods used, there is some coordination to be performed to make sure any supporting infrastructure needed is provided by other disciplines.

If a fiber network is used, this needs to be coordinated with the telecom designer. They will need to know the location of the fire alarm panel, which needs to be connected to provide an interface. Also, they will need to know if multimode or single-mode fiber is used and the fiber strand sizes. Providing them with this information allows them to include the fire alarm fiber pathways in their design.

When using the phone service to connect to a universal digital alarm communicator transmitter, the telecom designer will also need to know the location of the fire alarm panel. This is needed so they can route the telephone or VOIP lines to the proper location in the field for connection to the panel.

If a radio transmitter is used, this is typically specified by the fire alarm designer, but coordinating the location for the antenna needs to be coordinated with the building architect. It will need to be decided where on the roof the antenna is located and if a mast is needed. If a mast is needed, the details for size and its connection to the roof and supports will need to be coordinated.

Figure 7: See example of delayed-egress hardware equipment placement. Courtesy: Page

Two-way radio enhancement system

Emergency responder radio enhancement systems, sometimes called a distributed antenna system, are becoming a more regular part of building design. The systems ensure the radio systems for first responders are functional during an emergency event. The performance requirement to achieve certain signal strength within buildings was introduced into the International Fire Code after the Sept. 11 attacks. Because the requirements are a performance requirement it is sometimes uncertain whether the system will be required. In general, tall buildings, buildings with a large footprint, buildings with low-E glass used for energy efficiency and those with portions underground will require the system.

From a fire alarm aspect, there are components to the radio system that need to be monitored by the fire alarm system. NFPA 1221: Standard for the Installation, Maintenance and Use of Emergency Services Communications Systems, which has the majority of the requirements for the system, calls for monitoring of the following: Monitoring of integrity of power supplies, supervisory signals for donor antenna malfunction, radio frequency device failure, low battery, system component failure, etc. To properly coordinate, it needs to be determined if the system will be present in the building, who will be doing the design, when the design will be available and where the equipment is planned to be located.

As far as if the system is required, this should be determined as early as possible in the design. Some jurisdictions have a long grace period system if the building does not meet the required signal strength without the system, while others require the signal strength to be available to receive the certificate of occupancy. Sometimes, the need for the system is decided after a site signal survey is performed to estimate the available signal strength and compare it to the anticipated signal loss through the construction. A solution for the unknown situation is to leave space for the anticipated equipment and install empty riser pathways that could be used for wiring when the system comes into place.

Regardless of the path taken, once it is identified it is needed, the designer of the system needs to be determined. The electrical designer, the telecom/low-voltage designer, the fire alarm designer or a vendor could provide the design.

Once the design is in place, the fire alarm designer will need to locate the antenna, the head-end equipment and the signal booster locations. Typically, these are in stacked rooms in a tall building. It should be noted that the riser backbone needs to meet survivability requirements. At each location, fire alarm will need to provide monitor modules that connect to the equipment to ensure any change of status for the equipment gets reported properly to the fire alarm system.

The intent of this article is to provide a list of common fire alarm interfaces with other disciplines that sometimes get overlooked. There will be specific code requirements for each project and there are multiple ways to address the issues discussed from a design perspective. Include the topics within quality control and design checklists to make sure they are included in projects. It is better to have the items resolved during the design phase than to fix it during construction via multiple requests for information and change orders.

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