PURPOSE: To enable the operational function state of a circuit to be arbitrarily and properly changed by applying the constitution where a part of the predetermined circuit laid in an enclosure is operated from the outside thereof for changing the operation state of the circuit.

CONSTITUTION: A constitution is so made that an operational circuit section 5 as a part of the predetermined circuit 4 laid in an enclosure 2 is operated from the outside thereof for changing the operation state of the circuit 4. In this case, for example, a screw 6 coupled to the predetermined screw hole 9 at the pertinent position of the enclosure 2 is used for circuit operation, or a pertinent slender operation lever 8 is inserted through the predetermined small hole 7 formed at the pertinent position of the enclosure 2 for the circuit operation, as a method for externally operating the circuit 4 in the enclosure 2. According to this construction, operational parts such as a switch can be operated without opening or closing the cover of a sealed vessel containing the parts and without being easily known to a user. Thus, the predetermined setting change operation for electrical equipment can carried out efficiently and quickly.