Wheelock® Series MB Motor Bells
High-Output Audible Notification with Reliable 24 VDC Performance
The Wheelock® Series MB Motor Bells from KiddeFenwal deliver powerful, dependable audible notification for use with Kidde Fire Systems branded fire alarm and suppression systems. Available in 6-inch and 10-inch models, these bells produce high sound pressure levels (dBA) while maintaining low current draw for efficient operation.
Each bell features a durable, high-torque permanent magnet motor designed for long life and consistent performance. With versatile mounting configurations and lightweight aluminum shells, the Wheelock MB Series provides flexible installation and reliable operation for a wide range of commercial, industrial, and life safety applications.
Key Advantages
- Powerful Performance
Produces a high-output audible signal to ensure clear, attention-commanding alerts. - Energy Efficient
Low current draw minimizes load on NAC power supplies. - Durable Construction
Aluminum low-frequency shell provides superior sound projection and longevity. - Versatile Mounting
Multiple installation options including surface, semi-flush, outdoor, and concealed conduit.
- Easy Installation
Built-in trim plate simplifies semi-flush mounting and alignment. - Reliable Operation
Polarized design supports DC supervision of Notification Appliance Circuits (NACs). - Compliant and Proven
Meets major safety, performance, and accessibility standards for fire alarm signaling.
Applications
The Wheelock MB Series Motor Bells are ideal for:
- Fire alarm and suppression systems requiring clear audible notification
- Industrial and commercial facilities with moderate to high ambient noise levels
- Warehouses, plants, and large occupancy buildings needing high-impact signaling
- Retrofit or upgrade projects integrating with existing 24 VDC systems

System Architecture
Construction & Design
Shell Sizes: 6-inch and 10-inch
Material: Lightweight aluminum bell shell with durable red enamel finish
Motor: High-torque permanent magnet motor for consistent tone output
Mounting: Compatible with multiple configurations including surface, semi-flush, and outdoor applications
Wiring: Screw terminals for #12–#18 AWG wire; polarized for DC supervision
Trim plate: Integrated design simplifies semi-flush installation
Compliance & Certifications
- UL 464 – Audible Signal Appliances
- CAN/ULC-S525-07 – Audible Signal Devices for Fire Alarm Systems
- Factory Mutual (FM) Approved
- California State Fire Marshal (CSFM) Listed
- Chicago (BFP) Approve
- Meets OSHA 29 CFR 1910.165 Audible Alarm Requirements
Resources
Data Sheet: Wheelock® Series MB Motor Bells (K-75-004)
Resource links coming soon!
Performance That Rings True
The Wheelock® Series MB Motor Bells deliver the unmistakable strength and reliability that safety-critical systems demand. Engineered for durability, efficiency, and audibility, they’re built to perform when every second, and every sound, matters.



