Clamp-on Circuit Breaker Lockout Device – 120/277 Volt – 10 Pack

TRADESAFE clamp-on circuit breaker lockout devices provide a straightforward way to secure compatible single-pole 120/277V breakers in the off position during maintenance, repair, inspection, and electrical service work. This 10-pack is designed for breaker toggles measuring up to 5/8" wide by 1/2" thick, making it suitable for facilities that need multiple devices for recurring electrical isolation tasks.

Each breaker lockout combines a red polypropylene body, black nylon components, and a stainless steel thumbscrew for durable, nonconductive construction and tool-free installation. The included cleat helps the device grip compatible breaker toggles, while the integrated lock point accepts one safety padlock with a shackle diameter up to 19/64". Padlocks are not included.

Clamp-On Circuit Breaker Lockout for 120/277V Breakers

This clamp-on circuit breaker lockout is designed specifically for compatible single-pole breakers within the stated toggle dimensions. The thumbscrew mechanism allows the device to be tightened directly onto the breaker handle without additional installation tools, while the included cleat supports a secure fit on qualifying toggles.

Part number: TSMBRKR. Similar industry part number: 148698

Product specifications include:

• Quantity: 10 clamp-on breaker lockout devices
• Breaker compatibility: standard 120/277V single-pole circuit breakers
• Maximum compatible toggle width: 5/8"
• Maximum compatible toggle thickness: 1/2"
• Red polypropylene body
• Black nylon components
• Stainless steel thumbscrew
• Cleats included
• Tool-free clamp-on installation
• Compatible with 1 safety padlock per device
• Maximum compatible padlock shackle diameter: 19/64"
• Safety padlocks sold separately

Confirm the breaker type and toggle dimensions before ordering to ensure compatibility. This 10-pack is particularly useful for maintenance departments, electrical teams, and facilities that need identical lockout devices available across several panels or isolation points.

Single Pole Circuit Breaker Lockout with Tool-Free Thumbscrew

This single-pole circuit breaker lockout uses a clamp-and-thumbscrew design that can be installed without screwdrivers or other hand tools. The device is positioned over the compatible breaker toggle, tightened using the integrated thumbscrew, and then secured with the required safety padlock.

Construction and installation features include:

• Impact-resistant polypropylene construction
• Nonconductive nylon components
• Stainless steel thumbscrew
• Included breaker cleat
• Tool-free tightening mechanism
• Clamp-on design for compatible breaker toggles
• Integrated padlock attachment point
• One-padlock configuration
• Compact format for electrical panels and maintenance kits

The combination of the clamp body, cleat, and thumbscrew allows the lockout to be tightened firmly onto compatible breaker handles before a padlock is applied. Because breaker designs and toggle dimensions vary, users should always verify the breaker configuration and measurements rather than selecting the device based on voltage alone.

Circuit Breaker Lockout for Electrical Maintenance and Isolation

These circuit breaker lockout devices are suited to maintenance departments, industrial facilities, commercial buildings, electrical service teams, and other workplaces where compatible 120/277V single-pole breakers need to remain secured during servicing. The compact design makes the devices easy to keep in a lockout station, electrical maintenance kit, service cart, or portable LOTO bag.

To install the device, place it over the compatible breaker toggle, position the cleat as required, tighten the thumbscrew until the lockout is firmly seated, and attach one safety padlock through the integrated lock point. When work is complete and the isolation can be released, the authorized user can remove the padlock, loosen the thumbscrew, and remove the device from the breaker. 

To ensure compatibility, check out our Breaker Lock Solution Guidelines to find the right TRADESAFE Breaker Lockout Device for your specific breaker model and number of poles.

Choose the TRADESAFE 10-pack when you need multiple clamp-on devices for compatible single-pole circuit breakers across several panels or work areas. Verify the breaker toggle dimensions before use and pair each device with the safety padlock required by your facility. Keep electrical isolation equipment organized and ready for recurring maintenance tasks.