Abstract: A lock mechanism according to an embodiment includes an engaging portion, a hook, and a pressing portion. The engaging portion is provided in any one of a housing and a door that is configured to open and close a housing opening portion of the housing. The hook is provided in the other one of the housing and the door to be rotatable around a rotation axis, is engageable with the engaging portion, and is normally disengaged from the engaging portion by its own weight. The pressing portion is provided separately from the hook and is configured to press the hook. The hook includes a hook side engaging portion that is configured to engage with the engaging portion with the rotation axis interposed therebetween, and a hook side pressing portion that is configured to cause the engaging portion to engage with the hook side engaging portion by being pressed by the pressing portion.

Abstract: A protection relay device includes a housing and a fuse unit. The fuse unit includes a connection conductor, an input conductor connected to the connection conductor and receiving an external power, a fuse connected to the connection conductor, and an external device connection conductor connected to the fuse on a side opposite to the input conductor, and to which an external device is connected. A short-circuit induction conductor is provided on at least one of the input conductor on a side opposite to the fuse and the flapper portion, the short-circuit induction conductor protruding toward the other of the input conductor and the flapper portion.

Abstract: A ventilation device of an embodiment includes a housing, a shutter case, a fan, and a shutter. The shutter case has an opening. The fan is configured to exhaust air inside the housing to outside through the opening. The shutter partitions inside of the shutter case into a first chamber communicating with the opening and a second chamber different from the first chamber, and opens and closes the opening by a rotating operation. The fan is arranged on a first chamber side of the shutter case in the housing. The first chamber is a positive pressure region of the fan. The second chamber is a negative pressure region of the fan. The second chamber of the shutter case communicates only with the negative pressure region in the housing. The shutter is provided so that a pressure received from the second chamber is smaller than a pressure received from the first chamber.

Abstract: A ventilation device of an embodiment includes a housing, a shutter case, a fan, and a shutter. The shutter case has an opening. The fan is configured to exhaust air inside the housing to outside through the opening. The shutter partitions inside of the shutter case into a first chamber communicating with the opening and a second chamber different from the first chamber, and opens and closes the opening by a rotating operation. The fan is arranged on a first chamber side of the shutter case in the housing. The first chamber is a positive pressure region of the fan. The second chamber is a negative pressure region of the fan. The second chamber of the shutter case communicates only with the negative pressure region in the housing. The shutter is provided so that a pressure received from the second chamber is smaller than a pressure received from the first chamber.

Abstract: An insulating cover includes a cover main body and a pair of supporters. The cover main body is open in one direction along a radial direction of a tubular portion of a crimp terminal. The cover main body is configured to be disposed outside a terminal base. The cover main body is configured not to cover at least a region of a plate portion of the crimp terminal. The region is configured to face an electrical connection portion of the terminal base. The cover main body is configured to cover the tubular portion. The pair of supporters is configured to face at least one of an electrical wire and the tubular portion on a side opposite to the cover main body.

Abstract: An insulating cover includes a cover main body and a pair of supporters. The cover main body is open in one direction along a radial direction of a tubular portion of a crimp terminal. The cover main body is configured to be disposed outside a terminal base. The cover main body is configured not to cover at least a region of a plate portion of the crimp terminal. The region is configured to face an electrical connection portion of the terminal base. The cover main body is configured to cover the tubular portion. The pair of supporters is configured to face at least one of an electrical wire and the tubular portion on a side opposite to the cover main body.

Abstract: A protection relay device includes a housing and a fuse unit. The fuse unit includes a connection conductor, an input conductor connected to the connection conductor and receiving an external power, a fuse connected to the connection conductor, and an external device connection conductor connected to the fuse on a side opposite to the input conductor, and to which an external device is connected. A short-circuit induction conductor is provided on at least one of the input conductor on a side opposite to the fuse and the flapper portion, the short-circuit induction conductor protruding toward the other of the input conductor and the flapper portion.