Electromagnetic locks use the principle of bio-magnetic, when the current through the silicon steel sheet, the electromagnetic lock will have a strong suction tightly adsorbed iron plate to achieve the effect of locking the door. As long as a small current electromagnetic lock will have a great magnetism, control the electromagnetic lock power access system identification personnel that is correct after the power, the electromagnetic lock to lose suction to open the door. Because the electromagnetic lock has no complicated mechanical structure and the structure of the bolt, it is suitable for the passage control of the escape door or the fire door. Its interior is filled with epoxy to protect the body. At present, the suction strength of electromagnetic locks in LB (pounds), the test method is static pressure. The so-called static pressure is the electromagnetic lock is slowly and gradually gradually increase the tension on the adsorption of iron, when the electromagnetic lock beyond the suction moment to open the adsorption of iron, the ㄧ pull force data is the electromagnetic lock tension value. And the electromagnetic lock and the adsorption of iron must force the face to face and is linear pressure, so the electromagnetic lock suction is the maximum. Adsorption of iron because the electromagnet for a long time by the magnetic induction may be temporarily magnetized.
Electromagnetic locks are mainly used in indoor high-voltage switchgear before and after the cabinet doors need to be interlocked parts to prevent the occurrence of misuse, power generation and power supply departments indispensable blocking device. In addition, in order to meet the needs of integrated automation substation, some electromagnetic locks also increase the auxiliary contacts within the lock, which can provide the user with a pair of corresponding switch contacts at the combined position of the lock for user interlocking and integrated automatic sampling to avoid Going for an empty journey is the ideal locking device for modern substation equipment.