About this item
The Accentra SDA16-1-XL is the remote mounting version of Yale's SDA16 stand alone battery-powered door alarm. If you searched "stand alone door alarm", "door alarm with remote", "yale door alarm", "sda16", "yale alarm remote", or "what is this" - this is the product. Accentra is the current brand name for Yale commercial hardware under ASSA ABLOY. The SDA16 specifications carry forward directly from the Yale security catalog.
"What Is This": What the SDA16-1-XL Actually Does
If you searched "what is this" and landed here - the SDA16-1-XL is a door alarm unit that mounts on a door and sounds a loud alarm when the door opens without authorization. It is not a lock. It does not prevent the door from opening. It detects unauthorized opening and announces it with a 105+ decibel piezo horn alarm loud enough to be heard throughout a building corridor.
The unit continuously monitors the door's position using a magnetic contact sensor - the alarm body mounts on the door frame or door interior face, and a small magnet mounts on the opposing surface across the door gap. When the door is closed, the magnet sits adjacent to the alarm body and the circuit is complete. When the door opens, the magnet moves away from the alarm sensor, breaking the circuit and triggering the horn.
SDA16 vs SDA16-1-XL: The XL Remote Mounting Distinction
The base SDA16 mounts directly on the door or frame with the alarm body self-contained at the mounting location. The SDA16-1-XL is the remote mounting variant - "XL" designates extended lead or remote mounting configuration where the alarm body can be positioned separately from the magnetic contact sensor, extending the sensor lead to reach a mounting location that the standard configuration cannot accommodate.
This is the correct specification for doors where the frame geometry, door material, or frame obstruction prevents mounting the standard unit at the contact sensor location - wide stile aluminum doors, doors with frame inserts, and retrofit applications where the standard mounting position is blocked.
105+ Decibels: How Loud Is It
The SDA16 piezo horn produces 105 decibels or more at close range. For reference: a normal conversation is 60 decibels, a power saw at 3 feet is 110 decibels. At 105 decibels the alarm is physically startling to anyone near the door - it is designed to immediately deter the person opening the door and alert anyone within hearing range in the building. In a quiet corridor environment this alarm is audible from a significant distance and will not go unnoticed.
The piezo horn is the correct technology for this application because piezo elements produce sound through electrical vibration without moving mechanical parts - they work reliably for extended periods without wear and are not affected by door slam vibration the way speaker-cone alarms can be.
Dip Switch Settings: Field-Adjustable Features No Competitor Explains
The SDA16 has user-adjustable features set by internal dip switches. These are the most valuable operational details on the product - and the ones absent from every competitor product page:
Automatic alarm reset - When enabled, the alarm silences automatically after a set period and re-arms itself without key intervention. When disabled, the alarm continues sounding until manually reset by key.
REX (Request to Exit) time delay - Provides a brief period after authorized exit button activation before the alarm triggers, allowing authorized users to exit without tripping the alarm.
Passage time delay - A configurable delay period between door opening and alarm activation. Allows authorized users time to disarm before the horn sounds.
LED color preference - The LED indicator (which flashes every 30 seconds to confirm the unit is armed) can be set to different color preferences depending on visibility requirements.
These dip switch adjustments are made inside the unit - accessible by removing the cover with the cam lock key.
"Yale Alarm Remote": The Remote Reset and Arm Switch
If you searched "yale alarm remote" or "door alarm with remote" - the SDA16 accepts an external remote reset/arm switch (sold separately). This allows security staff or building management to arm and disarm the alarm from a different location - a security desk, a nearby room, or any convenient position - without having to physically reach the alarm unit at the door.
The alarm horn will sound until reset either by the key cylinder built into the cam lock on the cover or by the optional remote reset switch. For stairwell doors, rear exit doors, or loading dock doors where the monitoring station is not adjacent to the alarmed door, the remote switch provides practical operational control.
Tamper Switch Protection
The SDA16 includes an internal tamper switch. If someone removes the cover - either legitimately for maintenance or by attempting to defeat the unit - the tamper switch activates the horn immediately. The horn sounds until the unit is reset by key or remote. This prevents someone from simply unscrewing the cover and disabling the alarm before opening the door.
The cover is held in place by a keyed cam lock - a small cam lock that holds the cover over the mounting screws, electrical connections, and internal sensor, preventing casual access. The unit ships with a keyed-alike cam lock standard.
Power and Cylinder Options
Standard power is a 9-volt alkaline battery supplied with the unit. The LED flash every 30 seconds also serves as a battery status indicator - if the LED stops flashing, the battery needs replacement. For hardwired permanent power, the optional Model 784 power supply and WH-11 wire harness allow AC connection, eliminating battery replacement requirements on high-use installations.
Cylinder options for arming and disarming: a mortise cylinder (not included, order separately) installs in the alarm body for interior key control. A rim cylinder (not included, order separately) installs for exterior key control - arming the alarm from outside the door before locking up. Both cylinder types accept standard Yale/Accentra keyways to integrate into an existing key system.
Applications
Emergency exit doors, fire stair tower doors, rear exit doors in retail and restaurant environments, loading dock doors, roof access doors, and any opening where unauthorized exit should trigger an immediate audible alert. The SDA16 does not prevent exit - it announces it. This satisfies egress codes (inside egress always free) while providing security monitoring.
Specifications
Model: Accentra SDA16-1-XL / Yale SDA16-1-XL
Former Brand: Yale (now Accentra, ASSA ABLOY)
Type: Stand alone battery door alarm, remote mounting
Horn: Piezo, 105+ decibels
Power: 9-volt alkaline battery (supplied); hardwired via optional Model 784 power supply and WH-11 harness
LED Indicator: Flashes every 30 seconds - armed status and battery check
Dip Switch Settings: Auto alarm reset, REX time delay, passage time delay, LED color preference
Tamper Switch: Yes - horn activates if cover removed
Cover Lock: Keyed-alike cam lock supplied standard
Cylinders: Less cylinder standard; accepts mortise cylinder (interior) and rim cylinder (exterior) - order separately in desired keyway
Remote Switch: Accepts optional external remote reset/arm switch
Dimensions: 8.3" L x 3.1" W x 2.0" D
Finish: Gray
Sensor: Magnetic contact (magnet mounts on opposing door surface)
American Locksets has stocked Accentra and Yale door alarms since 2001.
Trusted Since 2001
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