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Seco-Larm Flush-Mount Magnetic Door Holder

Seco-Larm Flush-Mount Magnetic Door Holder

SKU: DH-171SQ

Regular price $64.99 USD
Regular price Sale price $64.99 USD
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SECO-LARM DH-171SQ – Flush-Mount Magnetic Door Holder (UL Listed)

Low-profile electromagnetic door holder with tri-voltage operation, designed for safety and convenience in commercial access control systems.

The SECO-LARM DH-171SQ is a flush-mounted magnetic door holder ideal for use with door closers in public buildings, stairwells, and fire-rated areas. It provides reliable holding power with automatic release in emergencies or power failure. This UL Listed holder features a cast aluminum faceplate, adjustable armature plate, and spike suppression circuitry for durability and safe operation.

Key Features:

• Holding Force: 33-lb (15kg)
• Voltage: 12/24 VAC/VDC or 120VAC
• Mounting: Flush-mount design
• Build: Cast aluminum faceplate with spike suppression
• Operation: Fail-safe with no residual magnetism
• Approvals: UL Listed

Ideal For:

• Stairwell and corridor fire doors
• Door control in schools, hospitals, and commercial buildings
• Applications requiring automatic door release upon fire alarm

Why You Should Use This:

• UL listed for reliable safety compliance
• Tri-voltage input for flexible installation
• Adjustable armature simplifies door alignment


Key Highlights:

  • ✅ 33-lb holding force for secure door retention
  • ✅ Adjustable armature plate adapts to door alignment
  • ✅ Spike suppression circuit protects internal components
  • ✅ No residual magnetism for easy door release

Frequently Asked Questions:

Q: Does this require a separate power supply?
A: Yes, it must be connected to a 12/24VDC/VAC or 120VAC source.

Q: Can this be used with fire alarm systems?
A: Yes, it is ideal for fire doors and stairwell control.

Q: Is it compatible with SECO-LARM door closers?
A: Yes, works with models like SD-C121-S, SD-C131-SQ, and others.

Holding Force: 33 lb (15 kg)

Installation: Flush-mount

Operating Voltage: 12/24 VAC/VDC, 120VAC

Current Draw:

52mA @ 12VAC

60mA @ 12VDC

27mA @ 24VAC

31mA @ 24VDC

24mA @ 120VAC

Magnet Box Weight: 1 lb 1.5 oz (468 g)

Door Armature Weight: 8.1 oz (230 g)

Electromagnet Dimensions: 2-3/4″ x 4-9/16″ x 2-1/16″ (70 x 116.5 x 52 mm)

Armature Dimensions: 2-9/16″ x 2-9/16″ x 1-9/16″ (65 x 65 x 40 mm)