Types of Electronic Door Locks
An electronic door lock is a critical part of your commercial access control system. Your card readers or fingerprint scanners aren’t worth much if your doors don’t unlock when your credentials are approved. Your locks need to be wired into your entry system so you can control them without a mechanical key – and that means more than automatically unlocking them. You need to be able to lock them down in the event of a security breach, unlock all of them during a fire or earthquake, and you want to keep a log of when they were opened.
Let’s be clear: we’re not talking about automatic door openers, although you can use them in conjunction with an electric door lock. We’re focusing on the locking mechanisms themselves, the latches and deadbolts.
Don’t forget, there’s a difference between latches and deadbolts. A latch is a spring bolt that returns to the strike plate when the door closes, usually with an angled face. A deadbolt is a simpler, single-throw bolt used to lock a door shut. Latches in a traditional lockset include a lock, but are generally more fragile than deadbolts. In simple mechanical locks, a pin-and-tumbler lock prevents the cylinder from unlocking the bolt unless the right key is inserted. In an electronic door lock, the bolt is connected to an actuator that releases with an electrical signal from the access control panel.
Installing An Electric Door Lock
The most common access control solution for upgrading to an electronic door lock is called a drop-in lock – it’s basically just a hardware replacement that uses all the same mounting locations on your doors. There’s nothing that says you can’t replace the door itself if you want a Mortise instead of a cylindrical lock, though. Your commercial access control system will be tailored to your unique security needs, of course, so how you replace your locks will depend on your personalized security plan.
The most common door-mounted electronic door lock, the rectangular box of a Mortise lock fits into a pocket (or mortise) inside the door. They usually include both a latch and a deadbolt in a single unit, but milling out the pocket is relatively difficult. However, since you’re already cutting a hole in the door (or using the existing pocket), running wires isn’t too inconvenient.
Cylindrical locks look a bit like Mortises, but they’re far simpler to install. Instead of requiring a pocket in the door, the latch and handle are installed through two simple holes bored in the door. They’re often not the most secure of locks, as they’re vulnerable to brute force without an accompanying deadbolt. These are most common for residential applications, but some internal doors in offices can use cylindrical locks.
Also known as crash bars or exit devices, these long push handles often incorporate their own external latch. They’re very common on external doors in retail and office buildings because they’re so easy to operate. Most crash bars can be locked open (known as “dogging”), retracting the latch and allowing the door to swing freely during business hours. Obviously, dogging the doors isn’t about access control but convenience – usually for retail stores, restaurants, or office lobbies. Some electric versions can be automatically dogged in addition to locked or unlocked, making them a popular choice for access control systems.
Installing Additional Electronic Door Locks
Alternatively, you can secure your doors without ripping out your existing locks by simply adding electric release mechanisms. They perform the same basic function, but installation is generally simpler.
Maglocks are the simplest electronic door locks, since by nature they need power to work. Electromagnetic locks are mounted on the top of the door frame, with a contact plate on the surface of the door. Locking the door sends power to the magnet, holding the door shut. Relatively simple to install, electromagnetic locks don’t require drilling a wire path into the door – you only have to wire up the magnet that sits above the door. Don’t confuse maglocks with door closers – they might be mounted in the same place, but locks don’t have an arm connecting the door to the frame.
Instead of trying to wire your door with a transfer hinge and a new electronic door lock, you might opt to just exchange the strike plate on your doorjamb. An electric strike allows controlled access by pivoting part of the strike plate without technically unlocking the door. The latch remains locked, but since the keeper is no longer in the way, it can swing open. Once the latch clears the keeper, it rotates back into place, forming a normal strike plate once more. They’re somewhat easier to install and wire than electric locks, but the type of frame determines just how easily you can put one in.
Planning Your System
An electronic door lock is a lot more complicated than just sticking a few wires into your existing door knobs or handles. You’ll have to replace the locks themselves in addition to running wires through the door and its frame. A transfer hinge is used to run wires into the door, which means you’ll also have to drill a path in the door to connect to the lock. A lot of your access control plan will depend on the construction of your building’s walls and doors, which determine how easy it will be to run those wires. Drywall and drop-ceilings are the easiest to work with, while poured concrete walls are the most challenging.
Wired or Wireless?
Hotels, smaller buildings, and other difficult sites to wire sometimes use wireless locks and readers installed directly on the door. Hotels may or may not link the readers together on a network – only the room key and the master key need to open an individual door – but other businesses might use wireless relays to create an access control network that can be managed by a central server. Bear in mind that while this reduces the wires you need to run, relays can negatively affect your bandwidth, have a limited range, and have difficulty connecting through dense materials like concrete. Difficult as it is to drill through concrete, industrial warehouses and manufacturing facilities might need to run wires if you have more than two access-controlled doors.
Fail-Safe vs Fail-Secure
Strange as it may sound, you’ll need to consider how your doors fail in addition to how they work. Depending on design, your doors will either lock or unlock if your building loses power. Failing safe means the door needs power to lock, and will unlock if the power is cut. A fail-secure door will stay locked even without power – no once can get in, but no one can get out, either.
Neither is definitively better; the choice you make depends on what the door opens to. Fail-safe doors are most often seen as emergency exits in access-controlled buildings. If you lose power in a fire, for example, you don’t want anyone trapped in the building. If you care more about intruders getting into sensitive areas when the power’s out, though, you’ll want a fail-secure lock on that door. Bear in mind that you can have both kinds of locks in your building, just not on the same door. Almost all the lock options mentioned here are available in both fail-safe and fail secure models, so you have a wide range of options when installing your commercial access control system.
Firewalls and Fire Doors
One final note before your security company starts drilling holes and tearing out doors: make sure you’re not working on a firewall or a fire-rated door. These are specifically designed to stop or slow the spread of a fire, and they must be modified by certified specialists according to regulations. Check your doors for fire-rating labels before you decide to install an electronic door lock.