This section is from the book "A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork", by The Colliery Engineer Co.. Also available from Amazon: A Treatise On Architecture And Building Construction.
The wiring for an elevator annunciator is not materially different from that used in the simple annunciator described in Art. 95. A single No. 14 wire, b, Fig. 78, is connected to one pole of the battery B and carried all the way up the elevator shaft, where connection is made to the pushes at each floor, as shown at 1, 2, 3, 4. The wires leading to the annunciator, in the elevator e, are laid side by side, and are made up into a single cable c for convenience, each wire being independently insulated; one end of the cable is then made fast at a point a midway up the elevator shaft, and connections are made from the remaining terminals of the push buttons to the wires in the cable leading to the corresponding annunciator drops. The electrical circuit is completed by a return wire r to the battery.