The electromagnet locks are one of the components of the Access Control System. It uses the magnetic force generated from the electromagnet to secure the doors to which they are being installed on. These systems has a built-in safety feature where they will be disabled in emergency situations like fire alarms being activated and power cuts to enable smooth evacuation of the occupants in the installations. In addition to that a "break-glass" switch is provided to enable the occupants inside the installation to release the locking mechanism to ensure that there are no unnecessary lock-ins occurrances.The designs and type of electromagnetic locking systems varies with the type and usage of the doors on which they are installed.

The types of electromagnetic locking systems which are current being used are:
1) EM Locking system
2) Electric drop bolt system
3) Electric door strike system

EM Locking system

This is the most popular and cost effective locking system which is currently being installed in access control system. It consist of a electromagnet lock which is mounted onto a door frame and a steel locking plate which is mounted onto the door. When electic current is applied to the lock, the electromagnet lock on the door frame will energise and hold on to the steel plate which is mounted onto the door. The holding power of the magnetic force is dependent on the type of locking system installed and it is in the range of 300Lbs to 1,200 Lbs. The most widely used models are the 600 Lbs holding force models. Optional brackets are avialable for the installers to mount the systems on various doors of different design and usage. The system is design to be disabled when there is a power failure or when the "break-glass" switch is activated. It is an optional feature to link the locking mechanism to the Fire Alarm panel as it involves linking and mantainence costs..

Advantages:
1) Low mantainence as there are no moving parts on the locking system.
2) It is relative easy to install compared to the other two systems, hence lower installation charges.
3) The system can be easily replaced hence the access control system will experience very limited down time due to equipment failure.

Limitations:
1) The doors on which the locks are installed can only be opened in one direction i.e. inwards or outwards.
2) The lock will protude from the top door frame or a protruding LZ bracket has to installed onto the door to install the locking steel plate should the lock be mounted flushed to the door frame.

Ebelco EM locking system

 

Electric drop bolt system

The system consist of a locking system which can be installed either on the floor or on the top of the door frame. When power is applied, a bolt protrudes from the lock and lodges itself into the strike plate which is mounted on the door frame. Optional brackets are avialable for installers to mount the system on different types of doors. The electric drop bolt is designed to retract when there is a power failure or when the "break-glass" switch is activated. It is an optional feature to link the locking mechanism to the Fire Alarm panel as it involves linking and mantainence costs.

Advantages:
1) It looks very pleasant aesthetically as the lock is mounted flush into or onto the frame with nothing protruding outwards. This is a preferred system to be mounted on glass doors and glass doorframes.
2) The electric drop bolt will not retract unless the "open button", access control release or the "break-glass" switch is activated, hence it is a very secured locking system.
3) The doors can open in both inward and outward directions.

Limitations:
1) A high quality "door closer" mechanism has to be installed onto the door system to ensure that proper alignment of the lock and the strike plate.
2) Higher installation charges compare to the EM lock to mount the lock and strikeplate. The locking system has to be properly aligned to ensure proper operation of the system.
3) Regular maintenence is needed to ensure the system is properly aligned and that the locks are clear of dust and grime (instances when the locks are installed onto the floor)
4) The end-user should purchase an extra set of drop bolt system as spares because the mounting positions of different brands of drop bolt system differs and thus replacement of the locking systems due to equipment failure can be troublesome if the end user cannot source the same brand of locking system installed at their premise.

EB200 Electric Dropbolt system

 

Electric door strike system

The electric door strike system replaces the locking plate on existing door locking system. When power is applied to the door strike system, it functions as an ordinary door locking plate to secure the door lock (on a permanent locked position) ; the door strike disengagesitself to enable the door to be pushed open when there is a power failure or when the "break-glass" switch is activated. It is an optional feature to link the locking mechanism to the Fire Alarm panel as it involves linking and mantainence costs.

Advantages:
1) Existing locking mechanism can be used and this is important if the end user has a preference to the design of the existing lock which has been installed at the doors.

Limitations:
1) Higher installation charges as it involves carpentary or metal work in install the strike at the locking plate position of the door. The locking system is very sensitive to the alignment of the door lock as well as the strike plate to ensure proper operation of the system.
2) Regular maintenance is needed to ensure that the system is properly aligned. The lifespan of the door strike is dependant on the proper alignment of the door system.
3) The market for door strike systems is relatively very small compared to EM lock and electric dropbolt systems and the spare part issue can be a problem over a long period of time. the mounting positions of different brands of door strikes differs and thus replacement of the locking systems due to equipment failure can be troublesome if the end user cannot source the same brand of locking system installed at their premise.

Ultimatey the choice in selecting the appropraite type of electromagnetic locking system rest on the expectations of the end user. Every system has it's merits and limitations. it is the end-users' responsibility to be aware of them and make an uniformed decision and carry certain spare parts if necessary to ensure proper operation of their locking systems. Do not depend on the installers to carry spares for your systems because they may not be around or interested to maintain your system after a few years.