The 140U-L-PAD4 Plug-In Block is an MCCB plug-in base adapter from Allen-Bradley/Rockwell Automation. It belongs to the bulletin 140U MCCB accessories product line. It is designed for use with 600 Amps, L-Frame rated molded case circuit breakers. It provides a mounting base and rear connection for the easy front removal or installation of a circuit breaker. When this plug-in adapter kit is used in switchboard applications, no terminals need to be used. The protection and the durability levels increase with the use of a plug-in adapter with the circuit breaker. The UL-approved 140U-L-PAD4 Plug-In Base Adapter provides power terminations and an adapter for the applications that need quick removal and replacement of circuit breakers. The breaker can be mounted in a vertical position angled at up to 90 degrees left or right. With this plug-in adapter, only one wire connection is needed at the load side.

The compact 140U-L-PAD4 Plug-In Base Adapter is suitable for use in electrical and power distribution boards. It allows the users to replace the circuit breaker easily and rapidly without even touching the connections on the base. It also allows for greater flexibility and future additions. Note that the extreme vibration can affect the performance, current-carrying, and safety operation characteristics of the adapter. During installation, all of the installation location's environmental characteristics must be considered. Insulation barriers can be used to improve the performance of the insulation as well as the circuit breaker and they can be easily assembled after the installation of the circuit breaker. The circuit breaker can be easily mounted on the plug-in based adapter. However, only trained technicians must perform the installation.