The FH EM series from DICTATOR Technik GmbH (Augsburg, Germany) comprises electromagnetic bar magnets purpose-designed as locking devices for clean room, laboratory, and pharmaceutical production interlock door systems. Unlike general-purpose access control magnetic locks, the FH series is engineered for the specific requirements of interlock logic — where doors must remain locked in normal state, release only when the interlock controller confirms the opposite door is closed, and provide positive feedback that the lock is engaged. An integrated potential-free feedback contact reports lock status to the interlock controller independently of the magnet power circuit, enabling the controller to distinguish between "door locked" and "magnet energized but door not fully closed."

How does the DICTATOR interlock system use FH magnets?

The FH bar magnets integrate with the DICTATOR ST3 peripheral interlock control terminal, which manages up to 8 doors (or 8 groups of 8 doors) using modular RJ45 flat cabling — no PLC programming or specialist knowledge required. The system operates on a normally-locked principle: all doors remain magnetically locked, and pressing the ST3's piezo-type operating key (rated for 20 million operations) temporarily releases the requested door after the controller verifies the interlock condition. DIP-switch configuration sets door release times, interlock logic, and emergency-open behavior. For clean room applications, the flush-mount FH UK variants present a smooth, crevice-free face to the clean side of the wall — eliminating the dust-trapping ledges that surface-mounted hardware creates.

What safety provisions apply to escape routes?

FH bar magnets designated "elTvtr" are TÜV Thüringen approved for installation on doors along escape routes. In the event of a fire alarm or power failure, the magnets de-energize and the doors release mechanically — the fail-safe open principle ensures occupants are never trapped. For doors requiring both interlock security and escape-route compliance, the ST3 controller can integrate an emergency-open mushroom pushbutton (IP65, illuminated) on the clean room side that immediately releases the lock independent of the interlock logic. The 12/24V DC supply voltage, drawn from a DICTATOR power pack (2.7 A or 5 A), keeps the FH magnets within SELV limits for safe installation in wet or conductive clean room wall constructions.