Basic Magnetic Lock System

Electromagnetic locks are widely used in commercial and industrial applications. The lock is usually mounted on the header above the door and the armature is usually mounted on the door (see drawing below). Different arrangements can be made for inswing or outswing doors, and different holding forces, monitoring switches, and other variations and options are available. In this article I will discuss only the basics.

As with any locking system, use of electromagnetic locks may be restricted by local authorities such as your local building inspector and/or fire marshall. It is wise to check with these authorities before installing an electromagnetic lock.

To install the most basic electromagnetic locking system on an out-swinging hollow metal commercial door and frame you need the following:

1. The electromagnetic lock
2. A way in
3. A way out
4. A power supply

The electromagnetic lock is an appliance. It unlocks when you shut off the power. Therefore the means of entry and egress will be swtiches of some form or other.

Means of entry could be:

• A key switch
• An access control device like a card reader or keypad
• A remote as for a garage door opener

Your choices for means of egress are limited by national, state and local life safety code. They could be:

• A mechanical push bar with a mechanical switch inside
• A pushbutton with pneumatic time delay clearly marked "Push to Exit" right next to the door
• An exit sensor with redundant pushbutton

Your local Authority Having Jurisdiction (AHJ) may require that your power supply be connected to the building fire alarm so that in the event of an alarm, the panel can unlock the electromagnet. In any case you need a power supply with sufficient capacity to power your electromagnet.

A simple electromagnetic locking system using products by Schlage Electronics might include:

• 1 each 390+ electromagnetic lock
• 1 each 505 power supply
• 1 each 653-05 key switch
• 1 each 621RD EX DA exit pushbutton

View these products at http://www.locknetics.com/

A simple electromagnetic locking system by Securitron might consist of:

• 1 each M62 electromagnetic lock
• 1 each BPS-24-1 power supply
• 1 each DK-26SS keypad
• 1 each XMS exit sensor
• 1 each EEB2 redundant exit pushbutton

View these products at: http://www.securitron.com/