Protective relay switch having trap door

Protective switch device, provided with at least one pole having contacts that can be separated, comprising:

• a box;
• a control mechanism that can cause opening and closing of the contacts;
• a protective means that can act in case of electrical failure to actuate the control mechanism;
• a manual control button;
• an electromagnet in the box and linked to the contacts for opening and closing the contacts, the electromagnet being controlled by the control button;
• a movable trap door that opens and closes an opening of the box, which opening provides access to a coil of the electromagnet;
• a trap door locking element that can be displaced between a closed position in which the locking element immobilizes the trap door to close the opening of the box and an open position in which the trap door can open;
• selective blocking means connected between said manual control button and said locking element for immobilizing the locking element in the closed position responsive to the manual control button occupying all positions other than a stop position in which the electromagnet is inoperative, and for freeing the locking element so that the locking element can be brought into the open position in response to the manual control button occupying the stop position.