LiftMaster LM21XPBB Fire Door Release with Battery

Battery Backup Fire Release Device for Rolling and Sliding Doors

The LiftMaster LM21XPBB is a UL-listed fire door release device with integrated battery backup, designed to safely release fire-rated rolling and sliding doors in the event of an alarm or power loss. Compatible with fusible link systems, this fail-safe unit supports up to four smoke detectors and two horn strobes while providing up to 72 hours of standby power. The LM21XPBB includes programmable alarm delay, ground fault detection, alarm and trouble relays, and diagnostic LEDs for system monitoring and code compliance.

Key Features

• Battery backup fire release device with up to 72 hours of standby time
• Supports up to 4 smoke detectors and 2 horn/strobes
• Programmable alarm delay: 10, 20, 30, or 60 seconds
• Normally energized fail-safe design with mechanical reset
• Ground fault monitoring and diagnostic LED indicators
• Trouble and alarm relay outputs for fire panel integration
• Audible trouble buzzer for battery or wiring alerts
• For use with rolling, sliding, or center-parting fire-rated doors

Technical Specifications

• Model: LM21XPBB
• Power Input: 120 VAC, 24 VAC, or 24 VDC
• Battery Type: 12V 4.5AH or 5.0AH sealed lead-acid (2 total)
• Battery Backup Time: Up to 72 hours
• Load Rating: Supports up to 40 lbs
• Dimensions: 9.7" H × 7.5" W × 5" D
• Weight: Approx. 18 lbs (with batteries)
• Compliance: UL-listed, NFPA 72 & 80 compliant
• Environment: Indoor dry locations only

Note

• This is a special order. Not eligible for return

Conclusion

The LiftMaster LM21XPBB offers enhanced fire safety with a reliable, battery-backed solution for emergency fire door release. With support for multiple initiating devices and clear system feedback via LEDs and relays, it’s ideal for commercial applications requiring fire code compliance and dependable performance.