WHICH TYPE OF LOCK SHOULD BE INSTALLED AND WHY?
One of the cornerstones of residential and commercial building security systems are physical access control systems, which can include turnstiles, commercial door locks, gates, and physical barrier systems. Locks and locking mechanisms are one of the most extensively utilized types due to cost, practicality, ease of implementation, and management.
Among the countless choices of locks to choose from when installing locks to secure a building, there are generally two categories of locks, i.e., fail-safe and fail-secure locks.
The terms “fail safe” and “fail secure” describe what happens when the access control system stops working or when the device loses power. When there is a failure, a fail-secure unit is locked, whereas a fail-safe unit is unlocked.
Understanding how each type functions and the applications best suited for each is essential since it will have an effect on the safety and security of building occupants, visitors, and property.
Definitions
Fail-Secure Locks: When power is cut or switched off, the lock engages, i.e., locks. Also known as fail-close.
Fail safe Locks: When power is applied or switched on, the lock disengages, i.e., unlocks. Also known as fail-open.
Fail Secure Locks
When there is no power, a door with a fail-secure lock remains locked from the outside, hence the word secure, i.e., no entry is permitted and the space beyond the door is secure. Its default state is a locked or secure position.
Applications
Fail-secure locks are often used in sensitive high-security spaces like vaults, IT equipment rooms, or areas with hazardous materials. This default setting works to prevent circumnavigation of the security system, where one might exploit an emergency or power failure to gain unauthorized access.
They can also be used in applications like stairways or fire-rated doors, which need to remain closed during a fire to prevent the fire from spreading beyond rooms, sections, or levels, effectively sealing off parts of the building.
Typical examples of fail-safe locks are electric strike/ electric latch locks.
While a fail-safe lock allows no entry in an emergency, e.g., during a lockdown or a fire when power fails, it can still be opened with a mechanical override, like a regular key that would be in the possession of a few authorized individuals.
For such sensitive rooms, it is imperative that the mechanical override key be kept in a secure place or in the hands of a few high-security clearance individuals, as it can be used to gain entry into such sensitive rooms without leaving an electronic trace.
NOTE: Regarding stairways and staircases, due diligence and consideration should be taken because there can be a lot of confusion in this regard. While securing doors, it’s important to determine whether a fail-secure door might hinder the movement of people between floors and sections during an evacuation. This, when not taken into serious consideration, can result in a catastrophe.
Fail Safe Locks
When power is interrupted, either due to an emergency or failure, the lock disengages and the door remains unlocked, allowing for safe, unfettered passage of people in the building, hence the term safe.
Fail-safe locks are unlocked in their default state and require power to engage. So during normal operation, they’re powered and locked to control access to specific areas.
To open a fail-safe lock, a user presents a valid credential, like a card or password. The reader momentarily disrupts power to the lock, and the door is open. Power is restored after a few seconds, and the door is locked again.
Applications
Fail-safe locks are mainly used on main entry points like lobbies, offices, classrooms, rooftops, stairwell doors, and general access doors—basically all areas that require re-entry and where tenants of a building require unrestricted movement in emergencies.
Electromagnetic locks or maglocks are by design fail-safe locks as they require power to energize the magnet and thus lock the door.
Egress
While fail-safe locks allow safe passage of people during emergencies, that doesn’t mean fail-secure locks do not allow passage of people during emergencies either. Both types of locks grant egress regardless of whether or not they’re powered. Egress is the action of going out or leaving a place.
The terms fail-secure and fail-safe only refer to security on entry into a space, which means the “key side” of the door, i.e., only the side that requires credentials to enter.
Exit is granted and should be granted for both fail-safe and fail-secure lock applications; otherwise, it could hinder emergency personnel like fire-fighters or medical staff in case of emergencies as they need unrestricted movement.
Electrified Panic Hardware
Electrified panic hardware or exit device devices refer to the levers that are used for stairwells or fire-rated doors to allow fast and easy egress to a building’s occupants in case of an emergency.
It’s used for fail-secure doors since the door is locked when power is cut, and the panic hardware device works to disengage the electric lock and allow anyone who might be trapped inside to exit.
Safe practices
In places with frequent power outages, office and building owners might decide to install a power backup system to keep fail-safe locks operational and prevent them from opening during a power outage and leaving an area vulnerable. This is particularly common in offices with glass doors because typically only magnetic locks, which are fail-safe by default, can be installed on glass doors.
However, this does not only defeat the concept of fail-safe but can also be catastrophic. Typically, when power is cut during an emergency, the power backup will still keep the lock engaged, and this can trap people who need free movement, resulting in panic and possibly a stampede.
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Although electronic strike locks are normally fail-secure, depending on the application, they can still be deployed in either a fail-secure or fail-safe configuration. By switching the polarity, it is possible to make the solenoids in the lock mechanism that move back and forth to lock and unlock positions retract or remain locked when power is applied or cut.
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Different applications require different types of locks for safety and security, though there’s the option of getting a hybrid lock, for instance, an electric strike lock that has the ability to switch modes from fail secure to fail safe.
Before a type of lock is selected for a specific location, the function should meet the programmatic requirements of the tenants and users of the building or local fire and security codes and regulations, if needed, especially for sensitive facilities.
A combination of fail-secure and fail-safe lock systems can help with the implementation of a comprehensive access control system that would help building owners and managers strike a balance between safety, security, and convenience.
A centralized access control system can help an administrator or manager identify which doors are open and which ones are closed and enable them to remotely open and close specific doors and passages during emergency events like lock-downs and evacuations
Slim Bz Techsystems : Nairobi, Kenya
Informative