SECO-LARM DH-171SQ Flush-Mount Magnetic Door Holder

Flush-Mount Magnetic Door Holder For Residential and Commercial Access Control

The SECO-LARM DH-171SQ is a UL-listed flush-mount magnetic door holder designed to control the release and closing of doors in residential, commercial, and public area applications including apartments, schools, hotels, hospitals, and offices. Featuring fail-safe operation and tri-volt coil compatibility, this unit holds doors open under energized conditions and releases automatically upon power interruption or remote signal to allow door closer operation. The included adjustable armature plate reduces installation time and accommodates door alignment changes without reinstallation. The flush-mount design integrates cleanly into standard single-gang wall boxes for a low-profile, professional finish in any access control environment.

Key Features

• UL-listed flush-mount magnetic door holder with 33 lb holding force
• Fail-safe operation releases door automatically upon power loss or remote signal
• Tri-volt coil accepts 12 VAC/VDC, 24 VAC/VDC, or 120VAC for flexible installation
• Adjustable armature plate included reduces installation time and adapts to door alignment changes
• Cast aluminum faceplate with no residual magnetism for smooth, reliable door release
• Built-in voltage spike suppressor protects against electrical transients
• Mounts to standard single-gang wall box for clean, low-profile installation
  
• Optional extension bars available in 3/4 in, 1 in, 4 in, and 7 in lengths

Technical Specifications

• Part Number: DH-171SQ
• Installation Type: Flush-mount (single-gang wall box)
• Holding Force: 33 lb (15 kg)
• Operating Voltage: 12 VAC/VDC, 24 VAC/VDC, 120VAC
• Current Draw: 52mA @ 12VAC, 60mA @ 12VDC, 27mA @ 24VAC, 31mA @ 24VDC, 24mA @ 120VAC
• Magnet Box Dimensions: 2-3/4 in x 4-9/16 in x 2-1/16 in (70 x 116.5 x 52 mm)
• Armature Dimensions: 2-9/16 in x 2-9/16 in x 1-9/16 in (65 x 65 x 40 mm)
• Magnet Box Weight: 1 lb 1.6 oz (498g)
• Armature Weight: 8.4 oz (237g)
• Faceplate Material: Cast aluminum
• Certification: UL listed (R38736)
• Warranty: 2-year limited
• Includes: Door holder, armature, jumpers, mounting hardware, 1 in extension bar, extension bar wrench

Conclusion

The SECO-LARM DH-171SQ provides reliable fail-safe door hold-open control with a clean flush-mount profile for residential and commercial access applications. Tri-volt coil compatibility and the included adjustable armature simplify installation across a wide range of door configurations. Confirm compatibility with your door closer and power supply before ordering to ensure proper system integration.