Electromagnetul se monteaza pe perete iar contraplaca pe usa. Pe timpul alimentarii, electromagnetul si contraplaca sunt lipite, astfel usa este retinuta in pozitia deschis pana la intreruperea curentului. Electromagnetul poate fi comandata de o centrala sau de buton.

1. 12 VDC (or 24 VDC) are the usual power source use in the control panel.	2. The control panel activates the fire alarm when a fire is detected.	3. The control panel activates the fire alarm when a fire is detected, and cut off the power source.	4. The Electromagnet door holder automatically releases the armature plate allowing the door to close to prevent the fire and smoke to spread to another room.