Alarm Lock 271 Armored door loop

The Alarm Lock 271 is an 18-inch armored door loop- a flexible armored cable with deep drawn anodized aluminum end brackets that transfers electrical power from the door frame to the door for electrified lock systems. If you searched "armored door locks", "fully armored door locks", "armored door loop", "door loop", "armored door lock", or "armoured door loop"- this is the product. BHMA Grade 1 commercial.

"Armored Door Locks" vs "Armored Door Loop": What the Search Actually Means

If you searched "armored door locks", "fully armored door locks", or "armored door lock"- you are likely searching for the power transfer accessory used with electrified door lock systems, not a lock with physical armor plating. An armored door loop is the cable assembly that routes wiring from the fixed door frame to the moving door. It is armored in the sense that the cable jacket is a flexible steel or metallic armor- a protective sleeve around the internal wires that resists abrasion, cutting, and the mechanical stress of repeated door swing cycles. The Alarm Lock 271 is this product.

What a Door Loop Is and Why Every Electrified Door Needs One

An electrified lock- a Trilogy electronic access control lever, an electrified cylindrical lock, an electrified mortise lock, or an Alarm Lock 715 exit device- is mounted on the door. The power supply and access control panel are mounted on the fixed wall or door frame. The door swings open and closed thousands of times per year. Every time it swings, the wires from the frame to the door must flex.

Without a door loop, installers typically run wires through the door hinge area loosely, tape them to the door edge, or drill through the door frame- all of which eventually fail from flex fatigue, pinching, or abrasion. A door loop solves this by providing a dedicated engineered flex path: the armored cable arcs in a loop from the frame bracket to the door bracket, absorbing the swing motion in the loop arc. The wires inside the armor never flex tightly at a single point- the stress is distributed across the full curve of the loop.

"Armoured Door Loop": British Spelling, Same Product

If you searched "armoured door loop"- the British spelling of "armored" is "armoured." Both spellings reference the same product. The Alarm Lock 271 is the armored/armoured door loop.

The 271 Physical Construction: Deep Drawn Aluminum Brackets

Every competitor lists "deep drawn anodized aluminum end brackets" as a spec without explaining what deep drawn means. This matters.

Deep drawing is a metal forming process where a flat sheet is pulled (drawn) into a die to form a three-dimensional shape in a single seamless piece. Deep drawn brackets have no seams, no welds, no crimps- the bracket body is one continuous piece of anodized aluminum formed from a single blank. This construction provides strength without the stress concentration points that welded or crimped brackets create. On a door bracket that experiences thousands of flex cycles per year, the absence of seams means no fatigue cracks developing at joint lines over time.

The anodized finish provides corrosion resistance in humid or exterior-adjacent applications- corridor doors in healthcare, government facilities, and commercial buildings where moisture and cleaning chemicals contact the hardware daily.

18 Inches: Why This Length

The 271 is 18 inches of flexible armored cable between the two end brackets. This length provides enough loop arc to accommodate standard commercial door swing (typically 90 to 180 degrees) without pulling tight at either extreme. At full open, the loop arc stretches. At door closed, the loop relaxes. 18 inches is the standard length for most hollow metal and wood commercial door applications at standard door frame offsets.

For wider doors, thicker door frames, or unusual swing geometries, confirm that 18 inches is adequate for the specific installation before ordering. The loop must not pull taut at full swing or bind against the door edge when closed.

Door Loop vs Electric Hinge: Choosing the Right Power Transfer Method

The Alarm Lock 271 armored door loop and an electric hinge (such as the Hager BB1279 1104 discussed elsewhere in this catalog) both transfer power from frame to door- but they work differently and suit different applications:

Electric hinge (Hager BB1279 ACSI Series): Wires route through the center knuckle of a ball bearing hinge. Invisible from outside, no visible cable, minimal door edge impact. Requires modifying or replacing the door hinges. Rated for continuous duty with specific UL current ratings (3.5A continuous, 16A pulse). Best for new construction or full hardware retrofit where hinge replacement is practical.

Armored door loop (Alarm Lock 271): Surface-mounted on door face and frame. Visible as a looped cable along the hinge edge. Installs without touching the door hinges- the existing hinges stay. No drilling through hinge barrel. Much faster and less invasive to retrofit onto existing doors. Best for adding power transfer to existing electrified locks without hinge replacement.

For retrofit applications where speed and minimal door modification matter, the 271 armored door loop is the correct choice.

Compatible Applications

The Alarm Lock 271 is confirmed compatible with the Alarm Lock 715 Series exit device with electrified trim. It is also used with any electrified lock system that requires flexible power transfer from frame to door- Alarm Lock Trilogy electronic access control locks, electrified cylindrical locks, electrified mortise locks, and magnetic locks mounted on the door face. Applicable in public buildings, commercial and industrial buildings, government and military facilities, retail, and multifamily applications.

Specifications

Model: Alarm Lock 271 / 271MS

Type: Armored door loop- flexible power transfer cable

Cable Length: 18 inches

End Brackets: Deep drawn anodized aluminum- conceals wire connections, no exposed terminations

Cable Jacket: Flexible armor- resists abrasion, cutting, and flex fatigue

Grade: BHMA Grade 1 Commercial

Compatible Devices: Electrified locks, Alarm Lock 715 exit device with electrified trim, Alarm Lock Trilogy electronic access control locks

Application: Power transfer from hinge-side door frame to electrified door hardware

Alternative to: Electric through-wire hinges (non-invasive retrofit option)

American Locksets has stocked Alarm Lock power transfer hardware since 2001.