Application:
The electro holding magnets are used as locking device for holding fire protection doors or similar applications, according DIN 4102 Bl. To reach the nominal holding force, the steel poles of the holding surface must cover the workpiece completely.

Design:
The magnetic circuit is open in switched-on position and makes it possible to hold ferro-magnetic locking discs. After switching off, a pressing device, located in the centre of the magnet, overrules the remaining holding force present between magnet and disc.
Depending on the application, fixed or moveable locking discs are used. The moveable execution of the locking disc is to be used when a complete parallel contact between holding magnet and fixed locking disc is not possible.All ferrous magnetic parts are galvanized. For electrical connection, two stripped wires are available.Mounting through a centred threaded hole (Exec. A ) or mounting flange (Exec. B ). Depending on the application, the appropriate rules for the prevention of accidents are to be followed.

In the housing of the magnet, two diodes (rectifiers) are fitted. One is connected parallel to the coil and suppresses the voltage peaks which occur when switching off and thereby prevents disturbance of electronic parts. The other diode is connected in series and prevents the holding magnet from damage in case of false connection. The electro holding magnets and the thereto belonging locking discs (on request) have been tested by the federation of insurers, e.V. Cologne, with report FSA V/76 of 3.5.76. They correspond to the requirements for such locking devices and the application guidelines for fire protection barriers of the institute for civil engineering, Berlin, regarding section 3.1.9 and have been approved. A constant quality control is accomplished by VDS Cologne.

Nominal voltage: 24 V DC

Isolation class: E

Protection: IP 65 according DIN 40 050

Duty:
25% at a maximum operation time of 2 minutes, respectively 40% at a maximum operation time of 30 seconds.

Notes to technical data:
The relative operation time is determined as follows:

rel. op. time = Duty ÷ operation time * 100%

The maximum holding forces are based on a suitable locking disc (on request) at an airgap of dL = 0 , 90% of nominal voltage and warmed condition (<15°C over-temperature without additional heat discharge). The values in the table give the maximum values in order to determine the correct electric accessories and are based on 20°C coil temperature at nominal voltage (VDE 0850). During operation the power decreases due to the temperature increase, depending on the duty. The inductivities are based on 24 V apparatus.