The catalog number 140G-G6S3-D12 designates a 3-pole, G-frame, Molded Case Circuit Switch manufactured by Allen-Bradley. It has a current rating of 125 Amps and an Interrupting Rating/Breaking Capacity of 65 kA. This circuit switch is intended to provide a means for the manual connection and disconnection of the conductors and devices in its downstream circuit. Some applications where the Allen-Bradley 140G-G6S3-D12 Molded Case Circuit Switch could be employed are in local isolation in motor installations, in isolation in a single machine or a group of machines, and in bus-tie isolation, just to name a few. This molded case circuit switch serves the purpose of applying locking and tagging procedures for safe machine operation and for the maintenance of electrical installations, but it cannot break the circuit automatically in the event of a short circuit or overload situation. For this reason, it is up to the users to protect the line side of the machine with a coordinated short circuit protection device.

In the OFF position, the Allen-Bradley 140G-G6S3-D12 Molded Case Circuit Switch ensures that there is sufficient electrical isolation to the circuit. It is the same size as thermal-magnetic circuit breaker equivalents and it can accept the same electrical and mechanical lugs and accessories as its thermal-magnetic circuit breaker equivalents. Mechanically speaking, it is also the same as its equivalent circuit breakers, with both an ON and OFF features that are controlled with a toggle switch. Since it cannot provide overcurrent or overload protection to the circuit, this type of circuit switch is mostly installed as a branch circuit isolator, which must be operated by hand when any major intervention in the panel board is required.