What is a Maglock?
The term 'maglock' is an abbreviation of the full and correct term 'Electro-Magnetic Lock'. These are electrically powered magnets which when energised (powered up), will grab hold of a metal plate fitted opposite to the magnet, creating a phenomenal hold typically anywhere between 250kg and 500kg per magnet. We've all seen the large cranes in scrap yards - even if only in the movies - which will magnetically pick up cars and trucks to effortlessly move them around the yard, and the principle is exactly the same here, just downscaled ever so slightly!!
They are often referred to simply as magnetic locks which stems from the word maglock, but this is technically an incorrect (or rather, incomplete) description for this type of lock. There are magnetic latches and locks on the market for lightweight cabinet doors - such as the childproof locks for your under-the-sink cabinet door or similar - which is of course not an electromagnetic lock, so there's a distinct difference!
What types of Maglocks are there?
There are lots of different maglocks out there, but the principle options are standard maglocks, slimline maglocks and double maglocks. We also offer some architectural profile handles with built-in maglocks which we'll also have a look at. All these types of maglocks are available monitored and unmonitored, which we'll go into a little further on.
These are your typical maglocks you'll most commonly see fitted on around modern purpose-built commercial buildings. They offer a better holding force than the slimline alternatives, simply due to the size of the magnet and the subsequent size of the coil within the housing.
As a rule of thumb, these full-size maglocks will offer you the higher-end of the holding forces on offer, typically around the 500kg / 1100lb mark. This is a phenomenal amount of holding force and generally suits most applications as long as there's space to fit them.
Slimline maglocks are designed with a much lower profile design, hence the term 'slim'. They are designed for fitting in tight spaces making them extremely diverse and scaleable to so many applications, from aluminium shop doors with really narrow frame designs, to cabinet spaces and hatches. We've even been involved in projects where these were to be used on flight simulator cabin doors because of their sleek unobstructive design.
As a rule of thumb, slimline maglocks will offer less holding force, but still in the 250kg region, giving you plenty of holding force for most applications - and of course, if you can't fit a fullsize maglock then this really is the only way to go regardless of required holding force, if indeed you feel a maglock best suits your purpose.
When you have a set of double-doors, you'll need a maglock for each door; but rather than fitting multiple maglocks with multiple cable runs, double-mags can be used to secure a set of double doors from one unit.
These are available in both full-size and slimline variations with the same principle as the above mentioned maglock types - only doubled-up for use on double door setups. Naturally they'll use double the power of a single maglock, but make for a much cleaner and simpler install than fitting two independent maglocks.
These are available in small single maglock handles, right up to full-length profile handles which will run the full height of the door, incorporating multiple maglocks for added strength.
This is actually a fantastically secure solution because the maglocks run along the opening/closing side of the door, rather than just at the head of the door. We've fitted these on library doors and similar, where public traffic is heavy and doors have previously been damaged unintentionally by visitors 'yanking' the door against the power of the maglocks when locked.
How do Maglocks work?
In simple terms, maglocks work by magnetically adhering to a metal counterplate - called the armature plate.
The magnet itself is designed with an electrical coil which when powered, creates a strong electro-magnetic field, which is how maglocks can offer such impressive holding forces. This means of course, that maglocks require power to lock. So in the event of power failure, they will fail-safe (unlocked), allowing free escape.
Of course, this all relies on the armature plate. This armature plate is a substantial thick piece of steel, secured to the door or frame opposite to where the maglock itself is positioned. When installed correctly, the armature plate will have a degree of 'wiggle-room', allowing it to fully adhere to the magnet, without any gaps - as we all know, one small gap on a magnet significantly reduces its strength, so this fitting knowledge is essential for correct operation and full holding strength.
In addition to this, there will usually be a small 'thrusting magnet' incorporated into the armature plate which is designed so that when the magnet de-energises (because the power was removed to unlock the door), if there's any residual magnetism left, this small magnet is designed to repel the magnet from the armature plate, effectively breaking this residual magnetism, allowing the door to be opened.
Monitored Maglocks vs Unmonitored Maglocks
As previously mentioned, all styles of maglocks can be obtained in monitored and unmonitored versions. In basic terms, monitored maglocks offer an output which allows you to connect a light, an alarm, or wire into a monitoring panel, which will send out a signal when the maglock is energised, letting you know the door is locked.
In most typical applications monitoring is not required, but for some settings it is essential that a sounder or light can be triggered when the door is open or closed - in these applications, getting a monitored maglock is critical. This allows you to have that form of monitoring you require - whether it be audible or visual - or indeed both! Just bear in mind as these are maglocks and only work when powered, the output will always be for when the maglock is in its energised state, so if you need the alert to be when it's unlocked rather than locked, simply using a handy relay you can achieve this result.
How are maglocks mounted?
There's an array of fitting brackets available for maglocks, namely Z brackets and L brackets, which can be seen in the header image of this article.
With maglocks, they always want to be fitted on the inside of the door, not on the outside. So depending on the direction of the door - inward opening or outward opening - and the space available above the door, you have to make a suitable selection of brackets in order to appropriately mount the maglock and the armature plate.
This is the part most people struggle with, so to make it simple, please take a look at our diagrams:
Typical Fitting on Inward-Opening Doors
Typical Fitting Options on Outward-Opening Doors
We hope this article has helped you understand a little more about how maglocks work, and their principle properties and functionality. If you do have any questions however, we're always happy to help and you are more than welcome to contact us with any queries you may have on how electromagnetic locks work - or indeed any other systems or products we sell.