(a) While repair or other work is being performed on equipment powered by an external source, that equipment must be locked out as required in paragraph (b) of this section or, if a lockout provision does not exist on the equipment, must be disconnected from the power source or otherwise deactivated, unless the nature of the work being performed necessitates that the power be connected or the equipment activated.

(b) If the equipment has a lockout or other device designed to prevent unintentional activation of the equipment, the lockout or other device must be engaged while the work is being performed on the equipment, unless the nature of the work being performed necessitates that the equipment be activated.

(c) A tag must be placed at the point where the equipment connects to a power source and at the location of the control panel activating the power, warning -

(d) The tags must not be removed without the permission of either the person who placed the tags, that person's immediate supervisor, or their respective reliefs.