An emergency door opening actuator includes electrical switches that are
at least one of normally open and normally closed. The electrical
switches may be connected accordingly in parallel or in series to
terminals of an overhead door operator. The terminals may correspond to a
push button circuit, an obstruction sensing circuit, an alarm system
circuit, and/or a door opening circuit. The emergency door opening
actuator may take advantage of a protocol in the operator to cause the
overhead door to open during an emergency condition to facilitate egress.
Likewise, the emergency door opening actuator may cause that the overhead
door cannot close by signaling the protocol in a predetermined way when
the switches are actuated by an emergency condition. The electrical
switches may be mechanically actuated when at least one fusible link is
broken.