The need to control access to buildings and internal areas within them has led to the proliferation of electronic locking systems. Their primary mission is to determine the identity of those who wish to enter through a protected door. Only those authorized to enter can unlock these electronic locks. Although this is a great way to protect a building, if it’s not performed properly, it can result in death and injury in a fire.
Access control systems commonly use electrically controlled locking mechanisms to prevent people from entering and from quickly leaving. Controlled egress is one way management can track the time that people come and go. It also enables an access control system to instantly know who still is in a burning building when the fire department arrives, for example. In retail installations, it also ensures customers pay for their items before leaving the building.
Unfortunately, controlling egress with electronic locking devices harbors the potential for death and injury in a fire.
“It’s important to have an overall strategy between the access and the fire alarm system that takes into consideration any special operational issues. It’s important to clarify who’s providing that capability,” said Jeff Hendrickson, director of sales, Silent Knight, Maple Grove, Minn., a Honeywell company. “I think you’re looking at an age-old problem—who’s responsible for what—and I think this is what contractors struggle with.”
According to Section 220.127.116.11 of NFPA 101, Life Safety Code, 2006 Edition, “Means of egress shall be continuously maintained free of all obstructions or impediments to full instant use in the case of fire or other emergency.” That pertains to the occupant’s ability to quickly and easily leave the building. The National Fire Protection Association of Quincy, Mass., wrote and published NFPA 101.
When working with electronic locks of this nature, electrical contractors (ECs) must be mindful of the pitfalls related to egress. To do this, they must have a working knowledge of the numerous fire codes that pertain to this issue. Although security is important, nothing is more important than the lives of those who occupy buildings. Seconds count in a burning building and often mean the difference between life and death.
Connect fire alarms to electronic locks
When a contractor installs a special lock that secures a door electronically, preventing occupants from quickly leaving, it usually is necessary to connect it to the building fire alarm system.
For instance, consider Section 18.104.22.168, NFPA 72, National Fire Alarm Code (NFAC), 2007 Edition: “Any device or system intended to actuate the locking or unlocking of exits shall be connected to the fire alarm system serving the protected premises.”
“Generally, the integration of access control with fire is something I consider to be on the access control side of the house,” Hendrickson said. “And that’s done either electronically or physically. There are a variety of ways to do it, too.”
The electronic locking mechanisms that cause low-voltage contractors the most grief are those that require more than a single action to release the door. In particular, electromagnetic and solenoid-type locks pose the biggest challenge where it involves ready, free egress.
Then, consider Section 22.214.171.124, NFPA 72, 2007: “All exits connected in accordance with 126.96.36.199 shall unlock upon receipt of any fire alarm signal by means of the fire alarm system serving the protected premises.”
Section 7.1.9 of NFPA 101, Life Safety Code, further defines the duties of an installing company where it involves access control and electronic locking systems: “Any device or alarm installed to restrict the improper use of a means of egress shall be designed and installed so that it cannot, even in case of failure, impede or prevent emergency use of such means of egress, unless otherwise provided in 188.8.131.52 and Chapters 18, 19, 22, and 23.”
Not all electronically controlled locking mechanisms need to be interfaced to a building’s fire alarm system, however. For example, in most cases, knob-and-key locks, working in conjunction with electronic door strikes, pose little or no concern to fire alarm installers. This is because most door strikes simply take the place of the strike plate in the doorjamb.
When an occupant wishes to leave a building equipped with a knob-and-key lock, all that is necessary is to turn the doorknob. To open the door remotely, power is applied and the “keep” within the door strike will allow the lock latch to freely move, thus opening the door.
Fail-safe and fail-secure locks
In the past, all that was necessary to electronically control a door was a door strike, electromagnetic (EM) lock or a solenoid lock. Installers simply placed a small power supply nearby and installed a pushbutton for someone inside the facility to use. But experience has demonstrated that when a fire erupts in a building equipped with this locking arrangement, people can find themselves trapped inside without any way to release the door.
There are two basic operating modes associated with the electronic locks discussed thus far: fail-safe and fail-secure.
With an electronic lock that uses the fail-safe method will default to its unlocked position when power is disrupted at the door or the electronic lock fails in some manner, allowing occupants to freely leave the building. Under the same conditions, those that use the fail-secure method will remain in a secure condition, preventing people from leaving.
EM locks are naturally fail-safe devices because they require power to lock a door. There are no moving parts in an EM lock; therefore, when power or the lock fails, the door can be readily opened. Solenoid locks, on the other hand, will remain locked when they rely on the fail-secure method of operation.
However, solenoid locks are rarely used today. When using this type of locking mechanism, always use the fail-safe type to ensure ready egress when power is lost or the mechanism fails.
Special locking arrangements
There are applications where the owner may ask for egress to be delayed when an occupant attempts to leave the building. Section 184.108.40.206.1(4) of NFPA 101, 2006, allows for a 15- or 30-second delay when the authority having jurisdiction approves.
Operation of the egress method must be in accordance with Section 220.127.116.11.9: “A latch or other fastening device on a door shall be provided with a releasing device that has an obvious method of operation and that is readily operated under all lighting conditions.”
There are other requirements installers must observe when installing electronically controlled locks on exit doors. Section 18.104.22.168.2 of NFPA 101, 2006, outlines them. In brief they are as follows:
1. An egress motion detector that will automatically unlock the door when it senses a person’s approach.
2. Loss of power must automatically release the door, so the occupants can quickly egress.
3. A manual means of lock release must be installed no less than 40 inches and no more than 48 inches from floor level. This device must be installed within 5 feet of the doors.
4. The mechanism used for manual egress must be clearly labeled “Push to Exit.”
5. When the manual egress mechanism is operated, it must result in the loss of power to the lock on the door. When operated in this manner, disruption must be direct and not through the access control system. When operation occurs, the doors must remain unlocked for at least 30 seconds.
6. When a fire alarm occurs within the building, all electronically controlled locking mechanisms must be released and the respective doors unlocked, so the occupants can freely exit the building. This unlocked condition must continue until the fire alarm system is reset.
7. When manual fire pulls, or manual fire alarm boxes, as NFPA 101 refers to them, are activated, setting off an alarm in the building, electronically controlled locks are not required to unlock.
8. Operation of an automatic sprinkler system or fire detection system must automatically unlock all electronically controlled locking devices. This condition must continue until the respective systems are restored.
The days when an installing company will get away with sticking an EM lock atop a door and a card reader outside are truly gone. Today, a request-to-exit pushbutton or panic bar on the door, an egress motion detector and the right method of fire alarm interface are required. There are other requirements according to NFPA 72 and 101 that installers must know about before they embark on the installation of an access control system.
To learn more about these fire codes, contact NFPA at 800.344.3555 or on the Web at www.nfpa.org.
COLOMBO is a 32-year veteran in the security and life safety markets. He currently is director with FireNetOnline.com and a nationally recognized trade journalist located in East Canton, Ohio.