As we have seen, electric strikers allow remote opening of a door fitted with a common mechanical lock, where you cannot or do not want to install a normal electric lock, such as in the case of French doors and interior doors. But how does it open? Pressing a button to trigger a lock seems such a simple action that it would not leave much room for choice. However, in reality, we have several options available to decide how and when it must be opened.
What happens if there is no electricity?
An electric lock is a fantastic thing. Until there is a power failure! It doesn’t happen often, but it can occur. An electric strike can deal with such an occurrence in one of two ways, depending on the type of coil which is fitted:
Fail secure: the striker remains closed during normal operation when it is not energised and it opens when, by pressing the button, it receives an electrical pulse. If their is a power failuretherefore, the striker remains closed. It is a solution which, in the case of a fault,favours security of the rooms, by keeping them closed.
Fail safe: the striker remains closed during normal operation because it is continuously energised and it opens only when, by pressing the button, the power supply is interrupted. Therefore, if there is a power failure, the striker opens, thus allowing free passage. It is a solution which, in the case of a faultfavours safety of individualsby ensuring the abilityto pass through as well as the possibility of evacuation in case of emergency.
There are 2 types of electric strikes: one which stays open if there is a power failure and one which remains closed (photo by ).
This function depends on how the electric strike has been designed; in particular how the coil is energised. It is therefore a characteristic which is selected at the time of purchase and cannot be changed at a later date.
Permanent or controlled opening
An electric strike also allows selection of the way the opening will be managed:
Permanent (or service) opening: by pressing the button the striker opens and it only closes after the door has been opened and re-closed. This is the most common type of operation.
Controlled (or security) opening: the striker only opens if, at the same time as the electrical pulse, pressure is exerted either manually or automatically on the door. In other words, therefore, if nobody opens the door when the button is pressed, the door remains closed. This prevents accidental openings. This the right solution when maximum security is required, as in the case of jewellery shops or supervised warehouses.
There are also 2 types of electric strikers with respect to the opening mechanism: one is opened simply by pressing the button, the other is opened if someone pushes the door whilst the button is pressed (photo by flickr/chrisinplymouth )
This feature also depends on the design of the striker and cannot be changed by the user.
“Dogging device”
The third useful feature is the possibility of lockingeasily the striker in the open position, for all those situations where the lock must remain open for long periods. This is the so-called “dogging device”, and it can be useful, for example, on access doorsto a building which is supervised by a concierge during the day, and can remain therefore open for sake of convenience, but it must remain shut at night.
In the Viro electric strikes, the dogging device can be activated simply by moving a small lever inside the striker.
The red circle highlights the lever which must be moved to activate and deactivate the dogging device in Viro electric strikers.
The convenience of electric strikers is therefore not merely that of being able to open a door remotely, but also carefully choosing how the opening must work. Convenience and flexibility combined. Before making a purchase it is well worth spending a few minutes to decide which solution best meets one’s needs, in order to take full advantage of everything an electric strike can do.