The Von Duprin 47856044 QEL-B is the modular buzzer kit for Von Duprin Quiet Electric Latch Retraction (QEL) exit devices. It adds audible notification specifically at the moment of initial latchbolt retraction, giving personnel at the door an immediate sound cue that the electric latch has released and the device is ready to open. This is a retrofit-only add-on, designed to be installed on existing QEL-equipped devices rather than ordered as part of a new device build.

The buzzer activates once at the initial retraction event. It doesn't run continuously while the latch is held open, which keeps the audible signal informative without being disruptive in noise-sensitive environments.

What the QEL-B Buzzer Kit Is Used For

In facilities where authorized personnel need real-time notification that a door has been electrically released, the QEL-B buzzer delivers that signal without requiring a separate monitoring system or remote alert. It's particularly relevant on service corridors, loading dock entries, and staff-access doors in hospitals, libraries, and museums where the base QEL system was already specified for quiet operation. The buzzer adds a local alert layer to an already quiet system, letting staff know when a credential or access control trigger has activated the latch retraction.

The QEL-B is also useful in K-12 and higher education settings where visitor entrances and administration offices use QEL-equipped exit devices and staff need to hear when a door has been remotely released without visual line of sight to the door.

Compatible Von Duprin QEL Devices

The 47856044 buzzer kit is compatible with QEL-equipped devices across the Von Duprin product line. That includes the 98/99 Series, 22 Series, and 33A/35A Series exit devices, as well as the 94/95 and 78/75 Series. In all cases, the QEL-B is an add-on to an existing QEL device; the base device must already have motorized latch retraction installed before the buzzer kit can be retrofitted.

If the device currently uses a solenoid-driven electric latch retraction (EL) rather than the motor-driven QEL, the correct path is to first convert the device to QEL using the appropriate modular conversion kit, then add the QEL-B buzzer.

How the Von Duprin QEL System Works

The QEL (Quiet Electric Latch Retraction) system replaced the older solenoid-driven EL design with a stepper motor assembly that retracts the latchbolt quietly. The system runs on 24 VDC, draws 1.0 amp inrush for approximately 0.5 seconds during retraction, and drops to a 0.14 amp holding current once the latch is open. Because the inrush is low, a standard 2-amp power supply supports the QEL, and longer wire runs are achievable compared to solenoid systems: up to 200 feet on 18 AWG wire, 320 feet on 16 AWG, 500 feet on 14 AWG, and 800 feet on 12 AWG.

The QEL platform features on-board installation and troubleshooting diagnostics, auto-adjusting latch retraction that compensates for latch throw and pull variance, and vandal detection that responds to tampering events. The system provides mechanical egress at all times regardless of power state, and it carries ANSI/BHMA A156.3 Grade 1 certification, UL 305 listing as Panic Hardware, and UL 10C listing as Fire Exit Hardware. The QEL-B buzzer kit is UL classified under Accessories for Single-Point Locks and Latches and Fire Exit Hardware (UL 10C).

QEL-B Ordering Note

Part number 47856044 is the retrofit buzzer kit only, not a complete QEL device. It cannot be specified on a new device order using this part number. For new QEL-equipped devices with a buzzer, the suffix -B is appended at the factory. This kit is the field-installable version for adding the buzzer to a QEL device already in service.